Essentials of Oral Pathology Swapan Kumar Purkait
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Developmental Anomalies of Oral and Paraoral StructuresCHAPTER 1

 
INTRODUCTION
Malformations or defects resulting from disturbance of growth and development are known as developmental anomalies. A large number of such developmental anomalies, which involve the body in general and oral structures in particular can occur during the embryonic life. Manifestations of such defects are evident either at birth or sometimes after birth. These anomalies often have some serious implications on the further growth and development of the involved organ during the later stages of life.
Moreover, developmental anomalies affecting the teeth are seen more often then any other defects in the oral cavity.
Disorders of development of teeth may be due to abnormalities in the differentiation of the dental lamina and tooth germs (abnormal morphodifferentiation), which results in various defects in the number, size and form of teeth.
Besides this, abnormalities in histodifferentiation may cause defective formation of dental hard tissues, resulting in the disturbance of tooth structure.
Disturbance in histodifferentiation often occurs at a later stage of tooth development as compared to the disturbance of morphodifferentiation.
 
DEVELOPMENTAL ANOMALIES OF ORAL SOFT TISSUES
 
ANOMALIES OF LIPS AND PALATE
 
LIP PITS AND FISTULAS
 
DEFINITION
Lip pits are congenital invaginations, which can involve either the paramedial portion of vermilion border of lower and upper lips or the labial commissural area.
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ORIGIN
The condition arises probably due to notching of the lip at the early stage of labial development, which causes fixation of tissue at the base of the notch. The condition may also arise due to failure of a complete union of the embryonic lateral sulci of the lip, which persist in the later life. Both lip pits and the commissural pits are developmental malformations, which appear to be inherited as autosomal dominant traits.
 
CLINICAL FEATURES
 
Lip Pits
  • The lip pit is a small depression over the lip, which can be either unilateral or bilateral and are more commonly seen on the lower lip.
  • These pits can be up to 3 to 4 mm in diameter and may have a depth of up to 2 cm.
  • Lip pit occur more commonly among females and their frequency ranges from 1: 75000 to 1: 100000 among Caucasians.
  • Congenital lip pits may occur either as an isolated condition or they may be associated with cleft lip and/or cleft palate (Van der Woude's syndrome).
  • The opening of a lip pit on the labial surface often appears as a circular or transverse slit, moreover a lip pit opening may be located at the apex of a nipple like elevation.
  • Mucous secretion is visible at the opening of those pits, which communicate with an underlying minor underlying salivary gland.
  • Since the salivary gland orifices open into these pits, as a result saliva often exudates from them. However, exudation of mucus from lip pits onto the lower labial skin may cause embracement to the patient.
 
Commissural Pits
  • The commissural pits measure from 1 to 4 mm in diameter, are found either bilaterally or unilaterally and often they have a familial tendency.
  • Commissural pits can occur in association with multiple preauricular pits.
  • Unlike lip pits, the commissural pits are more frequent among males and black people are affected more often than whites.
  • In both lip and commissural pits, there are no signs of inflammation or ulceration and both conditions are harmless.
 
TREATMENT
While commissural pits require no treatment, the lip pits are sometimes surgically excised for cosmetic reason.
 
DOUBLE LIP
Double lip is a developmental anomaly characterized by a horizontal fold of excess or redundant tissue, on the mucosal side of the lip. It is usually located on the inner aspect of upper lip, although the lower lip can also be occasionally involved.
 
CLINICAL FEATURES
  • Double lip is an oral anomaly, which can be either a congenital or an acquired one, the aquired type occurs mostly due to trauma.
  • The condition clinically appears as a “cupid's bow” when the lip is tense but it is not visible when the lip is at rest.
  • The defect can occur either alone or in association with other anomalies.
  • Double lip in association with blepharochalasis (dropping of the upper eye lid) and nontoxic thyroid enlargement are known as Ascher's Syndrome.
  • Clinically a double vermillion border is apparent with a transverse furrow between the two borders, when the patient smiles.
 
TREATMENT
Although, it is excised sometimes for cosmetic reasons, double lip mostly requires no treatment.
 
FRENAL TAG
 
DEFINITION
Frenal tag is a redundant piece of mucosal tissue, which projects from the maxillary labial frenum.
 
CLINICAL FEATURES
  • It is a familial condition and seems to be inherited as autosomal dominant trait.
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  • The shape and size of frenal tag varies from patient to patient and is clinically asymptomatic.
  • Sometimes, the condition is mistaken for a fibrous hyperplasia caused by local injury or irritation.
 
HISTOPATHOLOGY
Histologically, frenal tag consists of normal oral epithelium and connective tissue.
 
TREATMENT
No treatment is required.
 
HEREDITARY INTESTINAL POLYPOSIS (PEUTZ-JEGHERS) SYNDROME
 
DEFINITION
Peutz-Jegher's syndrome is a hereditary condition characterized by gastrointestinal hamartomatous polyposis in association with mucocutaneous pigmentations.
The disease is transmitted either through an autosomal dominant gene or it can occur spontaneously. It is a developmental condition and although pigmentation is an important feature of this disease, the primary disorder is actually not of the melanocyte system.
Incidence rate: Approximately, one case per 60,000 to 300,000 populations.
 
CLINICAL FEATURES
  • Peutz-Jegher's syndrome begins in infancy (2nd and 3rd decade of life) and there is no sex predilection.
  • Patients almost always have a positive history of the disease in the family.
  • There is multifocal melanin pigmentations in the perioral locations, which often manifest as discrete, brown to bluish-black or purpleblack macules on the skin.
  • The size of the macule varies from 1 to 5 mm in diameter and these macules often group around the oral, nasal and orbital orifices.
  • The pigmentation is most intense at the vermilion border of the lower lip and it often extends both to the facial skin as well as into the oral mucosa (crosses vermillion border in about 94 percent cases).
  • Buccal mucosa is the most frequently involved intraoral site, followed by palate, gingiva, tongue and floor of the mouth, etc. Sometimes these macules can be seen over the hands and feet as well.
  • The skin pigmentations tend to fade away in adult life, while the mucosal pigmentations continue to persist.
  • Intestinal polyposis is the other very important feature of Peutz-Jegher's syndrome besides the melanotic pigmentations. Although the polyps occur throughout the small intestine, colon and stomach are more commonly affected.
  • Presence of these polyps can cause recurrent abdominal pain (in patients younger than 25 years of age), unexplained rectal bleeding and prolapse of tissue from rectum with diarrhea.
  • Occasionally intussusceptions and intestinal obstruction may cause even death.
  • The syndrome can also cause precocious puberty, menstrual disturbances in females, gynecomastia in males and development of testicular mass, etc.
  • The polyps occur either as a hamartomatous growth or as an inflammatory lesion and they may have a very limited neoplastic potential.
  • There can be growth acceleration in few patients due to concomitant occurrence of sertoli cell tumor.
 
HISTOPATHOLOGY
Histologic examination of the oral macular lesions exhibits excessive accumulation of melanin granules in the basal cell layer.
 
DIFFERENTIAL DIAGNOSIS
  • Albright syndrome
  • Addison's disease
  • Oral melanotic macule.
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DIAGNOSTIC ASSESSMENT
  • Pigmentation in the perioral region is unique and often diagnostic for Peutz-Jegher's syndrome.
  • Radiographic examinations can be useful for detection of intestinal polyps.
  • Genetic counseling.
  • Familial history of the diseases also helps in making diagnosis.
 
TREATMENT
No treatment is required for the oral and perioral melanotic macules. However, surgical intervention may be required for the intestinal polyps causing intussusceptions.
 
ORAL MELANOTIC MACULE (EPHELIS)
 
DEFINITION
Oral melanotic macule is an idiopathic benign pigmented lesion of oral cavity; characterized by increased focal melanin pigmentations in the oral mucosa.
 
CLINICAL FEATURES
  • Oral melanotic macules present small, flat, well circumscribed, asymptomatic areas in the oral mucosa.
  • These are seen commonly on the vermilion border of the lip (mostly lower lip) near the midline. Intraorally, the gingiva, buccal mucosa and the palate are the most frequently involved sites.
  • Most of the lesions are less than one centimeter in diameter or sometimes little more and their color ranges from brown or black or bluish green, etc.
  • There is no specific age group for this condition, however middle aged females are most often affected.
  • The oral lesions are painless, firm in consistency and elliptical in shape.
  • Solitary lesion of oral melanotic macule on the lip is called labial melanotic macule.
  • The conditions are asymptomatic and have no malignant potential.
 
HISTOPATHOLOGY
  • Microscopically, oral melanotic macule presents diffuse accumulations of melanin granules in the basal keratinocytes and the lamina propria.
  • The lesions do not evolve from proliferation of melanocytes and there is no risk of malignant transformation in them.
  • Occasionally, melanin incontinence is observed with pigmented granules being seen in subepithelial melanophages.
  • Melanophagocytosis can also be seen.
 
DIFFERENTIAL DIAGNOSIS
  • Superficial melanoma
  • Blue nevi
  • Amalgam tattoo
  • Addison's disease
  • Peutz-Jegher's syndrome.
 
TREATMENT
The persistent, innocuous looking lesions do not require any treatment, however biopsy is mandatory for a definitive diagnosis of the condition as well as to rule out any possibility of malignant melanoma.
 
UVULA ELONGATA
 
DEFINITION
Uvula enlongata is a developmental anomaly characterized by abnormally long uvula, which touches or hangs lower than the base of the tongue.
 
CLINICAL FEATURES
  • The condition is usually seen at birth and sometimes it has a familial tendency for occurrence.
  • It is seen more frequently among females than males.
  • Although it is mostly asymptomatic, some sensitive patients may cough or gag when the elongated uvula touches the epiglottis or the base of the tongue.
  • Acquired cases of uvula elongata, may occur as a result of chronic pharyngitis due to cola nut chewing.
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DIFFERENTIAL DIAGNOSIS
Neoplasms of the uvula.
 
TREATMENT
In most of the cases, no treatment is required. However, in symptomatic cases, astringents can be used which will contract the uvula. In more severe cases, amputation is recommended.
 
CHEILITIS GLANDULARIS
 
DEFINITION
Cheilitis Glandularis is an uncommon, fundamentally benign, developmental anomaly of the lips characterized by chronic, progressive enlargement of the labial salivary glands.
Von Volkmann first introduced the term in 1870 and described it as a clinically distinct, deep suppurative, chronic inflammatory condition of the lower lip with mucopurulent discharge.
 
ETIOLOGY
  • Chronic exposure to sun (actinic damage), wind and dust
  • Factitial injury
  • Infection, e.g. HIV
  • Neoplasm especially squamous cell carcinoma
  • Use of tobacco
  • Emotional stress
  • Heredity.
Recent investigations indicate that overexposure to sun with superimposed bacterial infection is the more likely cause of this condition.
 
CLINICAL FEATURES
  • Cheilitis glandularis commonly occurs among middle aged or elderly adults and often there is a male predilection.
  • Inflammatory enlargement of the superficial or deep minor salivary glands of the lip often causes progressive, multinodular swelling.
  • There may be secretion of clear, viscous exudates from the minor salivary duct openings on the labial mucosa.
  • Enlargement of the labial salivary glands often cause eversion and induration of the lower lip.
  • Lower lip is involved more often than the upper lip and the vermilion borders as well as the labial mucosa are of normal color.
  • However in many cases, the lip shows diffuse keratosis with scaling of the surface.
  • Patient sometimes complain of burning discomfort or a feeling of rawness in the lip.
  • When the lip is everted due to swelling of the glands, its surface often reveals multiple pits or fistulas representing dilated and inflamed minor salivary duct openings.
  • Externalization and chronic exposure of the delicate labial mucosa often result in erosion, ulceration, crusting and infection, etc.
  • Few cases of cheilitis glandularis may undergo malignant transformation and produce carcinoma of the lip.
 
TYPES
Clinically cheilitis glandularis can be of three basic types:
  1. The simple type
  2. The superficial suppurative type and
  3. The deep suppurative type.
The simple type is the most common variant of the disease and it presents multiple, painless, pinhead size swellings on the lip with central depression.
The superficial suppurative type of cheilitis glandularis presents painless swelling of the lip with induration, areas of shallow ulcerations and crusting.
The deep suppurative type is characterized by deep seated inflammation, abscess formation in the lip with development of fistulas tracts. The disease often heals by scarring.
Many believe these subtypes probably represent a continuation of the same disease process, i.e. if 6the simple type of cheilitis glandularis is not properly treated, it becomes secondarily infected and progresses to the next type and then to the next.
 
DIFFERENTIAL DIAGNOSIS
  • Cheilitis granulomatosa
  • Crohn's disease
  • Bacterial infection (Elephantiasis nostras verrucosa)
  • Actinic cheilitis
  • Squamous cell carcinoma
  • Eczematous cheilitis
  • Chronic factitial injury.
 
HISTOPATHOLOGY
  • The surface epithelium can be either normal or hyperkeratotic.
  • The underlying salivary gland tissue shows hypertrophy and inflammation with distention of acini.
  • Squamous metaplasia of the ductal epithelium may be seen.
  • Dysplastic changes can be noted in some cases especially in type II and type III cases with increased risk of malignant transformation.
  • Frank evidences of squamous cell carcinoma are reported in about 18 to 25 percent cases in relation to this disease.
 
TREATMENT
Biopsy is mandatory especially in suspected cases, where the lip shows excessive keratosis or ulcerations.
Lesions with premalignant changes should be treated by surgical stripping of the lip without involving the vermillion border to save the esthetics.
 
CHEILITIS GRANULOMATOSA
Cheilitis granulomatosa is an atypical granulomatous disease of the lip, the origin of which is not clearly understood.
 
PATHOGENESIS
As mentioned above the exact cause of cheilitis granulomatosa is not known. Some investigators believe it as a regional form of sarcoidosis or Crohn's disease, while others suggest it as a granulomatous lesion of allergic origin.
The disease may also occur due to hypersensitivity to bacterial toxins from a chronic focus of infection in another nearby location.
 
CLINICAL FEATURES
  • Children and young adults commonly develop this disease (median age 25 years) and usually there is a female predominance.
  • Either lower or upper or both lips show a sudden diffuse, nontendered, nodular enlargement, which involves the entire lip.
  • Generally, the lower lip is enlarged on a more regular basis.
  • In some rare cases, patients exhibit lip swelling along with swelling of cheeks, eyelids and scalp, etc.
  • The swelling is usually painless, firm and exhibits no pitting upon pressure.
  • There is no sign of inflammation or ulceration on the surface of involved lips in the initial stage.
  • During the early stage, the disease is sometimes accompanied by fever, malaise and visual disturbance, etc. Regional lymph nodes are enlarged in about 50 percent cases.
  • The initial swelling subsides within few hours or days, however with more and more attacks of the disease, the swelling tends to become larger in size and persists longer, and eventually become permanent. Some lesions can even regress very slowly over the years.
  • Enlarged lips often create some cosmetic problems due to the presence of several cracks and fissures on the surface along with a reddish-brown discoloration.
  • Patient may also have difficulties during eating, drinking or talking.
  • Few lesions may exhibit scaling, fissuring and vesicle or pustule formation at the vermilion border. The fissured lip is often painful and is firm, rubbery in consistency.
  • Patients sometime complain of decreased salivary secretion and loss of taste sensation.
  • Cheilitis granulomatosa in association with facial paralysis and fissured tongue constitutes the “Melkersson-Rosenthal Syndrome”.
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  • The facial paralysis is intermittent at first but later on it becomes permanent in nature, the paralysis may be unilateral or bilateral, complete or incomplete.
  • Besides lip lesions, few other oral lesions can possibly occur in association with cheilitis granulomatosa, these include nodular or papillary tumor on the tongue, some multinodular lesions and a reddish or bluish plaque on the buccal mucosa or palate.
 
HISTOPATHOLOGICAL FEATURES
  • Microscopically, cheilitis granulomatosa (Fig. 1.1) shows granulomatous inflammation of the lip with infiltration by chronic inflammatory cells, chiefly lymphocytes, plasma cells and histiocytes.
  • The multinodular, noncaseating granulomas are often located close to the blood vessels and these are composed of epitheloid cells and swirled collagen fascicles with interspersed Langhans type of multinucleated giant cells.
  • These noncaseating granulomas often simulate sarcoidosis and these lesions may replace the minor salivary glands of the lip.
    zoom view
    Fig. 1.1: Photomicrograph of cheilitis granulomatosa
  • Generalized edema and dilated blood vessels are present throughout the connective tissue.
 
DIFFERENTIAL DIAGNOSIS
  • Sarcoidosis
  • Cheilitis glandularis.
  • Angioneurotic edema
  • Leprosy
  • Crohn's disease
  • Traumatic injury
  • Lymphoma
  • Edema and cheilitis subsequent to odontogenic infections.
 
TREATMENT
  • Intralesional injection of steroid (Triamcinolone) may result in reduction in the size of the lesion.
  • Surgical excision of the granulomas may be effective but often there is recurrence.
  • Elimination of odontogenic and periodontal infections in the vicinity may produce reduction in the signs and symptoms of the disease.
 
ANOMALIES OF THE ORAL MUCOSA
 
FORDYCE'S GRANULES
 
DEFINITION
Fordyce's granules are ectopic collections of numerous sebaceous glands, generally unassociated with hair follicles and are found in various locations within the oral cavity (Fig. 1.2).
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Fig. 1.2: Fordyce's granules
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CLINICAL FEATURES
  • Fordyce's granules are mostly seen in adult life and there is often a male predilection. These are rarely found in children before puberty.
  • They commonly occur in a bilaterally symmetrical pattern over the upper lip, buccal mucosa, gingiva, anterior pillars of fauces and occasionally over the tongue. Fordyce's granules are seen rarely in the lower lip.
  • Fordyce's granules can also be present in many extraoral locations such as the esophagus, genitalia, nipples, palms and the parotid glands, etc.
  • Normally these glands are present in the 60 to 70% of adult population but their number varies widely between individuals.
  • The number of Fordyce's granules in the upper lip increases during puberty while there is an increase in the number of these glands in the buccal mucosa in the later stages of life.
  • Fordyce's granules clinically appear as multiple, small, discrete, rice-like or milia-like yellowish-white bodies beneath the surface mucosa. They measure about 1 to 2 mm in diameter.
  • Those are completely asymptomatic conditions and in most of the cases patients are not aware of their presence in the mouth.
  • On occasions, clusters of numerous sebaceous glands may form slightly raised confluent plaques with a creamy appearance.
 
HISTOPATHOLOGY
  • Histologically, Fordyce's granules of the oral mucosa are identical to those of sebaceous glands, which are normally found in the skin, except the fact that they are not associated with hair follicles (Fig. 1.3).
    zoom view
    Fig. 1.3: Photomicrograph of Fordyce's granules
  • These glands are located superficially, quite close to the surface epithelium and are composed of 1 to 5 lobules.
  • They empty into a duct, which opens directly onto the mucosal surface. The duct may show keratin plugging.
  • The peripheral cells of the Fordyce's granules are flat and darkly stained, whereas the inner cells are lipid rich and pale in appearance.
 
DIFFERENTIAL DIAGNOSIS
The smaller size, multiplicity and typical yellow color are characteristic of the Fordyce's granules and are unlikely to be confused with any other mucosal lesions.
 
TREATMENT
No treatment is required for this condition. However, on rare occasions, sebaceous cysts or adenomas may develop from the preexisting Fordyce's granules.
 
FOCAL EPITHELIAL HYPERPLASIA
 
DEFINITION
Focal epithelial hyperplasia (commonly known as Heck's disease) is a condition characterized by multiple papillary or sessile hyperplastic areas in the oral mucosa.
 
ETIOLOGY AND PATHOGENESIS
  • The disease is specifically found among American Indians, Northern native people and other ethnic groups in Europe and Africa.
  • The exact etiology of Heck's disease is not known but it is probably caused by the Human Papilloma Virus (HIV) type 13 and 32.
  • Similar appearing lesions may also be encountered among HIVseropositive homosexual males.
 
CLINICAL FEATURES
  • The disease commonly occurs among children between the ages of 3 to 18 years and there is no sex predilection.
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  • Clinically, focal epithelial hyperplasia presents multiple, small, pedunculated, polypoid or nodular soft tissue growths in the oral cavity.
  • They also can appear as well demarcated, slightly raised plaques.
  • Sometimes several hyperplastic lesions may cluster together to produce a typical “Cobblestone” appearance.
  • Labial and buccal mucosa are the most common sites and lower lip is more frequently affected than the upper. However, the disease can also involve the tongue, gingiva and anterior faucial pillars, etc.
  • Individual lesions measure about 1 to 5 mm in diameter and are either white or pink in color.
  • Most of the lesions regress spontaneously after about 4 to 6 months and occasionally few lesions can recur.
 
DIFFERENTIAL DIAGNOSIS
  • Leukoplakia
  • Psoriasis
  • Keratoacanthoma
  • Veruciform Xanthoma.
 
HISTOPATHOLOGY
  • Focal epithelial hyperplasia histologically shows hyperparakeratosis of the covering epithelium with extensive acanthosis (increased thickening of the spinus cell layer).
  • The epithelial cells of the upper spinus layer show enlarged nuclei and vacuolated clear cytoplasms (koilocytes).
  • Deeper layer of epithelium reveals thickening, elongation and even fusion of the retepegs.
  • Basal cell layer of the epithelium exhibit increased mitotic activity.
  • Occasionally focal areas of liquefaction degeneration of the basal layer may be found.
  • The underlying connective tissue is loose, well vascularized and exhibit variable infiltrates of lymphocytes.
 
TREATMENT
Since focal epithelial hyperplasia is a harmless, self-regressing condition, it usually requires no treatment.
 
WHITE SPONGE NEVUS
 
DEFINITION
White sponge nevus or Cannon's disease is a congenital mucosal abnormality, which appears to follow an autosomal dominant hereditary pattern and manifests as a white lesion of the oral mucosa.
 
PATHOGENESIS
  • This condition is transmitted as an autosomal dominant trait with incomplete penetrance and variable expressivities.
  • Mutations in the genes coding for keratins 4 and 13 (the pair of keratins expressed by epithelial cells in the mucosa affected by the disorder) have been identified, suggesting the disorder as a hereditary keratin defect.
  • The heaping up of cells on the surface of the epithelium also suggests the possibility of an impaired normal desquamation process of the superficial strata of cells.
 
CLINICAL FEATURES
  • White sponge nevus has its onset mostly during childhood. Some lesions are congenital and are present at birth and few lesions may even initiate during the adolescent period.
  • There is no sex predilection, several members of the same family are often affected.
  • The intraoral lesions are almost always bilateral and are mostly found over the buccal mucosa and tongue. Occasionally, the vestibular mucosa, palate, gingiva and floor of the mouth, etc. are also affected.
  • Besides the oral mucosa, white sponge nevus can be seen on the conjuctivital, esophageal, nasal and anogenital mucosa as well.
  • Clinically, white sponge nevus presents a thick, bilateral, asymptomatic, deeply folded or corrugated white or gray lesion on the oral mucosa.
  • The surface of the lesion is soft, uneven and has a shaggy appearance with a spongy consistency.
  • The lesions can be either diffuse or patchy and have a translucent opalescence similar to that of leukodema.
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  • The disease can sometimes present ragged white areas, which can be peeled off by gentle rubbing without any ensuing bleeding.
  • It is a perfectly benign condition but is often mistaken for leukoplakia.
 
HISTOPATHOLOGY
  • White sponge nevus histologically shows marked thickening of the epithelium with mild to moderate hyperparakeratinization, acanthosis and spongiosis.
  • Marked intracellular edema of the spinus and parakeratinized cell layer of the epithelium is an important characteristic feature of the disease.
  • The cells with intracellular edema show vacuolated cytoplasms and shrunken (pyknotic) nuclei.
  • Intrestingly under microscope only the cell walls and the pyknotic nuclei at the centers of the cells are visible, which often gives rise to a so called “basket weave” appearance.
  • Parakeratin plugging is another important finding in white sponge nevus, which runs from the surface and extends deep into the spinus layer.
  • Individual cell keratinization may be seen in spinus cell layer.
  • The basal cells are intact and the lamina propria shows no inflammatory changes.
  • There is no evidence that this lesion undergoes malignant transformation.
 
ELECTRON MICROSCOPIC STUDY
Ultra structural studies of white sponge nevus reveal that some cells of the spinus layer differentiate early and become enriched with tonofilaments.
 
DIFFERENTIAL DIAGNOSIS
Thick, corrugated, diffuse white lesion in the mouth, with history of involvement of several members of the same family is usually suggestive of white sponge nevus.
However the following diseases are to be considered in the differential diagnosis of white sponge nevus.
  • Leukoplakia
  • Hereditary intraepithelial dyskeratosis
  • Lichen planus
  • Candidiasis
  • Leukodema.
 
TREATMENT
No treatment is required for this disease.
 
DEVELOPMENTAL DEFECTS OF THE GINGIVAE
 
FIBROMATOSIS GINGIVAE
 
DEFINITION
Fibromatosis gingivae are rare, benign, diffuse, noninflammatory hyperplasia of the gingival tissue, which sometimes cover the entire teeth.
It is a hereditary condition, which is transmitted as an autosomal dominant trait. The disease is probably the result of a diffuse infiltrative hyperplasic proliferation of the fibroblast cells and mature collagen fibers of the gingival tissue.
 
CLINICAL FEATURES
  • Clinically the disease is characterized by dense, diffuse, smooth or nodular overgrowth of the gingival tissue.
  • Fibromatosis gingivae can be either generalized or localized in nature and it is similar in appearance to the dilantin hyperplasia of gingiva.
  • The gingival enlargement mostly appears in young children or it may be present even at birth, however in some cases the swelling may not be noticed until the adult life.
  • Both sexes are equally affected in gingival fibromatosis.
  • The gingiva shows multinodular enlargements especially in the interdental papilla regions.
  • The gingival tissue changes become obvious soon after the eruption of the deciduous teeth.
  • The hyperplastic tissue is firm, painless and retains the normal coral pink color of gingiva.
  • Sometimes the markedly enlarged gingiva may cover the entire crown of the erupted teeth. The eruption process of teeth is however normal.
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  • Elimination of dental plaque does not make any significant reduction in the severity of the disease.
  • Occasionally, the condition is associated with hypertrichosis, epilepsy and mental retardation, etc.
  • Gingival fibromatosis can also be associated with other syndromes, e.g. Cowden's syndrome and Rutherford's Syndrome (features of individual syndrome are given in the relevant chapter dealing with syndromes).
  • Moreover, gingival fibromatosis can be a feature of “Laband Syndrome”, which is characterized by splenomegaly, enlarged nasal and external ear soft tissue, shortened terminal phalanges, hypermobility of joints and hypoplasia of nails.
  • Sometimes symmetrical fibrous overgrowths may occur bilaterally in the maxillary tuberosity region and few of such cases are possibly related to gingival fibromatosis.
 
HISTOPATHOLOGY
Histopathologically gingival fibromatosis presents the following features:
  • The covering epithelium is hyperplastic and often exhibits thin elongated retepegs.
  • The fibrous connective tissue consists mainly of course bundles of collagen fibers with scattered mature spindle shaped fibroblasts few of which are multinucleated.
  • Mucoid changes in the gingival connective tissue may occur due to the accumulation of excessive amount of ground substances.
  • There are significant numbers of mast cells often associated with the fibroblastic proliferation.
  • Histologically, hereditary gingival fibromatosis is indistinguishable from other forms of gingival enlargements including those which are drug-induced.
 
DIFFERENTIAL DIAGNOSIS
  • Phenytonin (Dilatin) sodium induced gingival hyperplasia.
  • Generalized hyperplastic gingivitis.
  • Leukemic infiltration of the gingiva.
History of familial involvement is extremely important in making the diagnosis of the disease.
 
TREATMENT
Periodic gingivectomy with placement of gingival acrylic splints for cosmetic and functional reasons.
 
RETROCUSPID PAPILLA
Retrocuspid papilla is a slightly raised area of mandibular alveolar mucosa, which as the name implies, is commonly located lingual to the cuspids.
  • This structure measures about 2 to 4 mm and is often present bilaterally between the marginal gingiva and the mucogingival junctions.
  • Retrocuspid papilla is more common among children and it has structural resemblance to the incisive papilla.
  • Histologically, the papilla represents a focus of fibrovascular tissue with an orthokeratinized or parakeratinized surface and it usually covers an osseous foramen of a nutrient blood vessel.
 
DEVELOPMENTAL ANOMALIES INVOLVING THE JAWBONE
 
AGNATHIA
Agnathia refers to the complete failure of development of jawbone, involving either maxilla or mandible or even both the jaws. It is an extremely rare condition, however, often a portion of the jawbone, e.g. premaxilla, condyle, or ramus, etc. can be developmentally missing.
 
MICROGNATHIA
Micrognathia is an orofacial anomaly characterized by development of jaws, which are unusually smaller than normal (Figs 1.4 to 1.8).
 
CAUSES
  • Pierre-Robin syndrome
  • Hallerman-Steriff syndrome
  • Trisomy 13
  • Trisomy 18
  • Turner syndrome
  • Marfan syndrome
  • Progeria
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zoom view
Fig. 1.4: Micrognathia (seen from front)-I
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Fig. 1.5: Micrognathia (seen from side)-II
 
TYPES OF MICROGNATHIA
Micrognathia can be of two types:
  1. Pseudomicrognathia
  2. True micrognathia
Pseudomicrognathia: It is a condition where normal sized jawbone appears to look smaller when compared with the opposing jaw. A jawbone of standard size may appear smaller, if the opposite jaw is larger than normal or if it is positioned more posteriorly in relation to the skull.
True micrognathia: It is the condition, where the jawbone is actually smaller than normal and it can be either a congenital or an acquired problem.
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Fig. 1.6: Hemifacial microstomia (seen from side)-I
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Fig. 1.7: Hemifacial microstomia (seen from front)-II
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Fig. 1.8: Radiograph of hemifacial microstomia
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The congenital micrognathia may follow a hereditary pattern and it often occurs in association with other congenital diseases such as Pierre-Robin Syndrome or congenital heart disease, etc.
Congenitally missing premaxilla often leads to maxillary micrognathia and patients with this anomaly show retracted middle third of the face.
Congenital mandibular micrognathia may occur due to posterior positioning of the condyle in relation to the skull.
Acquired micrognathia mostly occurs due to trauma or severe infections in the orofacial region especially in younger age. It may cause difficulty in feeding the child. Ankylosis of the temporomandibular joint in young individuals often leads to mandibular micrognathia with retruded chin.
 
CLINICAL FEATURES OF MICROGNATHIA
  • Micrognathia often results in defective alignment of teeth, crowding and malocclusion, etc.
  • Retruded chin with small face.
  • Difficulty in feeding the children.
  • Difficulty in proper articulation and speech.
 
MACROGNATHIA
Macrognathia is a developmental anomaly characterized by an abnormally large jaw. The condition can affect both the jaws at a time but more often it involves either maxilla or mandible.
 
TYPES OF MACROGNATHIA
True macrognathia: When the jawbone is abnormally large in size in true sense, it is called true macrognathia.
Pseudomacrognathia: A normal sized jaw may look larger when the opposing jaw is smaller than normal in size. This condition is known as pseudomacrognathia.
 
COMMON CAUSES OF TRUE MACROGNATHIA
  • Pituitary gigantism: It is often associated with abnormally large jawbones. Both jaws are affected in gigantism and the bony overgrowth is proportionate to the generalized increase in the size of the skeleton.
  • Paget's disease of bone: Paget's disease often causes increase in the size of maxilla, which is directly related to the generalized overgrowth of the cranium.
  • Acromegaly: Progressive increase in the size of mandible occurs in cases of acromegally.
  • Leontasis ossea: It is a form of fibrous dysplasia of bone and the disease is often associated with enlargement of maxilla.
  • Hereditary causes: Mandibular prognathism often occurs hereditarily.
Mandibular prognathism may occur due to anterior positioning of the lower jaw in relation to the cranium, even though the exact size of the jaw is normal.
However, there are certain factors, which cause mandibular prognathism and thereby create an appearance of mandibular macrognathia.
These factors are as follows:
  • Increased height of the ramus.
  • Increased length of the body of mandible.
  • Increased gonian angle.
  • Decreased maxillary length.
  • Posterior positioning of the maxilla in relation to the cranium.
  • Prominent chin button.
  • Varying soft tissue contours.
 
CLINICAL FEATURES OF MACROGNATHIA
  • Mandibular protrusion (when manduibular bone is affected).
  • Gummy smile (mostly maxillary).
  • Ramus of mandible forms a less steep angle with body of the mandible.
  • Excessive condylar growth.
  • Prominent chin.
 
TREATMENT
In case of macrognathia, surgical correction (osteotomy) of the abnormally large jaw is often performed for both functional and esthetic reasons.
 
FACIAL HEMIHYPERTROPHY
 
DEFINITION (Figs 1.9 and 1.10)
Facial hemihypertrophy is a developmental condition characterized by disproportionate unilateral enlargement of the face (Figs 1.9 and 1.10).
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Fig. 1.9: Facial hemihypertrophy (seen from front)-I
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Fig. 1.10: Facial hemihypertrophy (seen from side)-II
Though the name is hemihypertrophy the actual underlying condition is a hyperplasia.
Although most humans exhibit some degrees of facial asymmetry only few individuals actually develop clinically significant facial hemihypertrophy.
 
ETIOLOGY
Although, a number of factors have been proposed to explain this condition, the most important ones appear to be vascular and neurogenic disturbances that cause an increased neurovascular supply to the affected side of the face resulting in its overgrowth. Other possible factors include the following:
  • Hormonal imbalance
  • Incomplete twining
  • Chromosomal abnormality
  • Defective intrauterine development (due to asymmetric intrauterine pressure)
  • Lymphatic abnormalities.
 
CLINICAL FEATURES (FIGS 1.11 AND 1.12)
Facial hemihypertrophy clinically exhibits the following features:
  • Unilateral enlargement of the facial soft tissues, bones and teeth.
  • A positive family history is reported in many of these cases.
  • Either side of the face can be affected and there is a slight female predilection for this condition.
  • The asymmetry is more specifically noticed in the frontal bone, maxilla, palate, mandible, alveolar process, condyles and the associated soft tissues.
  • The skin is thick and coarse on the affected side and also there is presence of thick and abundant hair (hypertrichosis).
    zoom view
    Fig. 1.11: Facial hemihypertrophy-III
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    Fig. 1.12: Radiograph of facial hemihypertrophy
  • The sebaceous and sweat glands on the affected side show excessive secretions.
  • The ear and eye on the affected side may also be enlarged.
  • Unilateral enlargement of the cerebral hemisphere may cause mental retardation and seizure in about 15 to 20% cases.
  • There can be an increased incidence of certain systemic conditions in facial hemihypertrophy such as Wilms, tumor of kidney, adrenocortical tumor and hepatoblastoma, etc.
  • On rare occasions, the hypertrophy may extend beyond the face and include the limbs or even the entire one side of the body.
 
ORAL MANIFESTATIONS
  • Unilateral macroglossia with an increase in the size of the fungiform papilla is often seen.
  • Crowns and roots of teeth, especially of the permanent teeth are often enlarged on the affected side.
  • The teeth on the affected side may also erupt prematurely.
  • There is often early shedding of deciduous teeth on the affected side.
  • The jawbone proper is larger and thicker on the affected side.
  • Because of the osseous and dental asymmetries in facial hemihypertrophy malocclusion often develops.
  • Because of the overgrowth of soft tissue, buccal mucosa on the affected side appears pendulus and velvety, and folds of tissue may hang from there in the oral cavity.
 
DIFFERENTIAL DIAGNOSIS
Differential diagnosis of facial hemihypertrophy includes the following:
  • Neurofibromatosis
  • Fibrous dysplasia is of bone
  • Arteriovenous malformations of jaws.
 
TREATMENT
No treatment is usually required for facial hemihypertrophy. However, selective surgical treatments may be performed to improve functional and cosmetic status wherever necessary.
 
FACIAL HEMIATROPHY
 
DEFINITION
Facial hemiatrophy also known as Parry-Romberg syndrome, is a developmental anomaly characterized by progressive decrease in the size of one side of the face due to atrophy of the facial structures.
 
ETIOLOGY
The exact etiology of the disease is not known however certain possible factors have been identified which can precipitate the condition. These factors include the following:
  • Peripheral nerve dysfunction
  • Trauma
  • Heredity
  • Peripheral trigeminal neuritis
  • Infection
  • Regional systematic sclerosis.
 
CLINICAL FEATURES
  • The condition usually begins in the first or second decade of life. Many cases may be present since birth.
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  • Initially a slightly depressed vertical furrow or line is noticed at the midline of the forehead and eyebrow.
  • As the condition progresses, facial tissues on the affected side including the skin, subcutaneous tissue, muscle and bone, etc. become atrophic, resulting in facial deformity.
  • Usually the left side of the face is involved more often than the right side.
  • Affected side of the face shows hyperpigmentation of skin with loss of hair.
  • Severe cases may often result in hollowing of the cheek and depressed eye in the orbit.
  • Other features associated with facial hemiatrophy include trigeminal neuralgia, contralateral jacksonian epilepsy and ocular and hair changes.
  • The cartilage of the ear, nose and larynx, etc. may be affected.
  • Occasionally the disease may affect other parts of the body.
 
ORAL MANIFESTATIONS
  • Intraoral tissues on the affected side exhibit an overall atrophy.
  • Delayed development of the jawbone.
  • Tooth eruption on the affected side may also be retarded.
  • Teeth on the affected side often have shorter crowns and roots.
  • Development of the roots of teeth on the affected side is also delayed.
 
TREATMENT
There is no effective treatment for facial hemiatrophy. Progression of the condition ceases after certain age and it remains static thereafter for the remaining part of life.
 
CLEFT LIP AND CLEFT PALATE
Cleft lip and palate are the most common developmental defects in the head and neck region.
 
DEFINITION
Cleft lip: It is a developmental anomaly characterized by a wedge-shaped defect in the lip, which results from failure of two parts of the lip to fuse together at the time of development. This defect is more commonly seen in relation to the upper lip.
Cleft palate: It is a developmental defect of palate characterized by lack of complete fusion of two lateral halves of the palate resulting in a cleft. Cleft in the palate leads to communication between oral and the nasal cavity.
Cleft of the maxillofacial skeleton are quiet common entities and these can involve many structures of the orofacial region.
These developmental defects often have very serious impacts on the growth, development and functions of the involved facial organ. Moreover, such defects can jeopardize the appearance of the face and badly affect the personality of the patient as well.
 
ETIOLOGY
The etiology of cleft lip and cleft palate covers both hereditary and environmental factors.
 
Hereditary Factors
Heredity is the most important single factor in the development of cleft lip and cleft palate. Different studies indicate that nearly 40 percent of cleft lip cases with or without cleft palate are hereditary in origin. Heredity also plays role in the development of about 20 percent cases of isolated cleft palate.
Moreover research also indicates that cleft lip or cleft palate of hereditary origin can occur either due to polygenic influence or monogenic influence.
Polygenic inheritance of cleft lip or cleft palate: If the origin of the disease is influenced by several different genes acting together, it is known as 17polygenic inheritance. It is presumed that every individual carries some genetic liability for clefting and only if the combined liabilities of both the parents exceed a minimum threshold level, then clefting occurs in their offspring.
Monogenic inheritance of cleft lip and cleft palate: When clefting is influenced by only a single gene, it is called monogenic defect. Moreover the cleft lip and cleft palate of monogenic origin can be associated with numerous other syndromes.
 
Environmental Factors
Several environmental factors have been identified which probably play an accessory role in the development of cleft lip and cleft palate.
The factors include the following:
  • Nutritional factors such as deficiency of or excess of vitamin A and deficiency of riboflavin.
  • Maternal smoking (during pregnancy) is a very high risk factor.
  • Psychogenic, emotional or traumatic stress in pregnant mothers.
  • Relative ischemia to the area due to defective vascular supply.
  • Mechanical obstruction by enlarged tongue.
  • High dose of steroid therapy during pregnancy.
  • Localized mucopolysaccharide metabolism defect in the area.
  • Infections.
  • Substances such as alcohol, drugs or toxins in the circulation.
  • Pathological conditions like Streeter's fetal dysplasia.
  • Lack of inherent developmental force.
 
PATHOGENESIS OF CLEFT LIP AND CLEFT PALATE
Cleft lip and cleft palate usually develop due to incomplete obliteration and maturation of different embryonic processes, which are associated with the formation of normal lip and palate.
  • Mandibular cleft (lower lip and/or mandibular bone) usually occurs either due to failure of the copula to form the mandibular arch or due to persistence of the central groove of the mandibular process. Mandibular clefts are mostly midline defects.
  • Cleft of the upper lip and premaxilla occur due to failure of mesodermal penetration and subsequent obliteration of the ectodermal grooves between the median nasal process, lateral nasal process and the maxillary process, which occurs during the seventh week of intrauterine life.
  • The tongue occupies the space between two palatal halves during the initial phase of development. however, ninth and tenth week of intrauterine life are associated with mandibular enlargement and gradual downward movement of the tongue.
  • If the tongue does not move downwards sufficiently, the palatal shelves remain separated and do not rotate to their horizontal position, this causes lack of fusion between the palatal shelves resulting in clefts.
  • Palatal fusion occurs anteroposteriorly and is completed in between 11th and 12th week of the intrauterine life.
  • Isolated cleft of the palate develops due to the failure of fusion between two palatal shelves in the midline.
A number of both genetic and environmental disturbances have been isolated, which can cause breakdown of the normal series of interdependent events or steps during the development of facial structures and result ultimately in cleft formation.
  • Disturbed mesenchymal cell migration and/or proliferation: Failure of fusion of facial growth centers or palatal processes due to impaired mosenchymal cell replacement after palatal fusion.
  • Suppressed cell division in associated structures: Reduced growth of cranial and/or Meckel's cartilages.
  • Impaired intrinsic tissue function: Reduced tongue mobility and delayed ability or inability of palatal processes to elevate.
  • Disturbance in inductive tissue interactions: Aberrant message leading to failure of palatal fusion.
  • Suppressed programmed epithelial cell death following fusion: Incomplete palatal fusion or reopening of fused processes.
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INCIDENCE OF CLEFT LIP AND CLEFT PALATE
Incidence varies with racial and geographic background. Incidence of cleft lip and/or cleft palate is about 1 in 800 child births (range in 1:500–1:2500). It is interesting to note that when a couple have their first baby born with the defect of either cleft lip or cleft palate or both, their second baby will carry a 1% risk of having the same defect. The incidence of cleft lip and cleft palate are on the rise among modern population because the modern maxillofacial and plastic surgery can provide hugely improved and almost perfect esthetic rehabilitation to those patients who had cleft lip or cleft palate.
After the perfect surgical repair, the grown up people do not have any problem in free social mixing. Moreover, marriages between such people, who are genetically harboring the defect may give birth to children with even higher risk of developing cleft lip and cleft palate.
 
COMMON SYNDROMES ASSOCIATED WITH CLEFT PALATE
  • Pierre-Robin syndrome
  • Goldenhar syndrome
  • Median cleft face syndrome
  • Oral facial digital syndrome
  • Apert's syndrome
  • Cleidocranial dysplasia
  • Schenthaner-Marie-Sainton syndrome
  • Nagar syndrome
  • Elashy-Waters syndrome
  • Crouzon syndrome
  • Larsen syndrome.
  • Treacher-Collins syndrome
  • Marfan syndrome
  • Otopalatodigital syndrome
  • Down syndrome
  • Edward's syndrome.
 
CLINICAL FEATURES OF CLEFT LIP AND CLEFT PALATE
  • These defects occur more commonly among male people.
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  • Most common type of cleft in both sexes combined is cleft lip and palate (Fig. 1.13).
  • Most common type of isolated cleft lip only is unilateral complete type.
  • The mildest form of cleft palate is the cleft uvula.
  • Clefting involves left side of the face more often than the right side.
  • As cleft palate creates a communication between the oral and the nasal cavities, patients often feel difficulty in taking foods and drinks due to nasal reflux or regurgitation.
  • Breastfeeding is impossible to babies having cleft lip or cleft palate, as they cannot generate sufficient suction.
  • In case of cleft palate, upper anterior teeth may be misplaced, deformed or impacted.
  • Bony deficiency of upper jaw may cause retrusion of maxilla with narrow arched palate.
  • Maxillary canine or premolars on the affected side may contact in lingual occlusion to the corresponding mandibular teeth due to retrusion of the maxillary bone.
  • Deflection of nasal tip towards the non-cleft side and larger naris on the clefted side.
  • Bilateral complete cleft is the worst situation, where complete separation of the anterior palate occurs (Fig. 1.14), which projects towards the mid portion of the lip and is attached only by the nasal septum.
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    Fig. 1.13: Cleft lip and palate
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    Fig. 1.14: Bilateral complete cleft palate
  • Increased susceptibility to middle ear infections via the auditory tube.
  • Difficulty is correct phonation and articulation of speech.
  • There may be associated major congenital defects in the body including heart defects, spina bifida and mental deficiency, etc.
  • Mental trauma to the child due to the unusual appearance as well as due to the speech problems, which often prevents them from mixing with other children freely.
  • Improper or untimely surgical correction of these defects may also cause persistence of some ugly appearance and defective speech; moreover improper surgical correction may also result in an unbalanced growth of the mid face region in future.
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TREATMENT
Treatment should be aimed at achieving the following goals:
  1. Restoration of feeding to the children.
  2. Proper development of speech.
  3. Prevention of maxillary arch collapse.
  4. Cosmetic repair of the face and lips.
    • Cleft lip is treated surgically in the first week after birth, when the blood hemoglobin level is high and the kid is protected by the maternal antibodies.
    • Sometimes, the surgery may be deferred until the baby attains 2 to 3 months of age, as by this time, the infant becomes adapted to its independent existence.
    • Generally, cleft palates are corrected surgically at the age of 18 months or immediately after that. This particular time is selected since after this age there will be development of speech and any further delayed in treatment will cause abnormal speech development.
    • Familial, social and psychological support is necessary during the protracted management.
    • Obturators may be given in untreated adult patients with palatal clefts. The appliance helps in keeping the palatal clefts closed and thereby helps in speech and taking food.
 
DEVELOPMENTAL ANOMALIES OF THE TONGUE
 
AGLOSSIA
Aglossia is an extremely rare congenital defect characterized complete absence of the tongue. This condition is usually associated with other serious developmental defects in the body. Sometimes it occurs in association with aglossia-adactylia syndrome characterized by congenital absence or severe hypoplasia of tongue with absence of the digits.
 
MICROGLOSSIA
Microglossia is a rare congenital anomaly in which only a tiny or rudimentary tongue develops in the oral cavity. Although microglossia may develop as an isolated case but in most cases it occurs in association with other congenital anomalies, e.g. oromandibular limb hypogenesis syndrome or hypoglossia-hypodactylia syndrome, etc.
  • Microglossia without limb deformity can occur but they are also associated with some other birth defects such as partial anodontia, sublingual gland hypertrophy and dextrocardia, etc.
  • However, patients with microglossia don't have severe speech difficulties or difficulty in taking food.
  • Small children often have problem in sucking milk.
  • Since the size of the tongue often determines the growth and size of the mandibular arch, in case of microglossia the length of the mandibular arch is often smaller.
  • Moreover, the smaller mandibular arch length often leads to development of severe malocclusion.
 
MACROGLOSSIA
Macroglossia is a relatively common condition characterized by an abnormally large tongue in the oral cavity.
 
TYPES
Macroglossia can be either congenital or acquired (secondary) in nature.
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Relative Macroglossia
Relative macroglossia is a condition in which a normal sized tongue appears abnormally large if it is particularly enclosed within a small oral cavity. It happens mostly in cases of maxillary retrusion or in cases of restricated growth of nasopharynx.
Lymphangioma restricted to the tongue or in continuity with a cystic hygroma of the neck is the most common cause of macroglossia.
Relative macroglossia can also occur in conditions like enlarged tonsils or adenoids, habitual posturing of tongue, low palate with reduced volume of oral cavity and mandibular retrognathism, etc.
 
Apparent Macroglossia
Apparent macroglossia is a condition, where the tongue appears abnormally large due to poor muscular control of the tongue, although there is no real increase in the bulk of the tongue tissue. Apparent macroglossia is often seen in cretinism and in “Happy puppet” syndrome.
 
CLINICAL FEATURES OF MACROGLOSSIA
  • Macroglossia causes displacement of teeth and malocclusion as the enlarged tongue creates continuous pressure or thrust on the teeth.
  • It may disturb the process of speech and food intake to some extent.
  • Some macroglossias may cause cosmetic deformity.
  • The lateral margin of the tongue exhibits scalloping or indentations as the tongue is always pressed against the teeth.
  • Children with macroglossia often develop tongue-thrusting habits, which may lead to malocclusion, open bite and diestema formation, etc.
  • Macroglossia developing in adult people (as in acromegaly or in tumors, etc.) may produce spacing of teeth and distortion of the mandibular arch.
  • Blockage of the pharyngeal airway due to macroglossia may result in a condition called “obstruction sleep apnea”, which is characterized by intermittent cessation of respiration during sleep.
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  • Macroglossia can also be an important component of “Beckwith's hypoglycemic syndrome, which features—neonatal hypoglycemia, mild microcephaly, umbilical hernia, high birth weight and postnatal somatic gigantism.
It is important to note that CT scans can be helpful in determining, if the tongue size is normal or there is any deviation.
 
TREATMENT
  • Removal of the primary cause whenever possible.
  • Surgical reduction or trimming may be required when macroglossia disturbs the oropharyngeal function or is causing some major cosmetic problems.
 
ANKYLOGLOSSIA
 
DEFINITION
Ankyloglossia can be defined as a congenital developmental condition characterized by fixation of the tongue to the floor of the mouth; causing restricted tongue mobility. During functional movements, the tip of the normal tongue should touch the anterior palate but in case of ankyloglossia, it fails to reach up to that limit.
Complete ankyloglossia is an extremely rare condition, however partial ankyloglossia, which is otherwise known as “tongue-tie” is a relatively common developmental anomaly of the tongue. The tonguetie occurs either due to a short and thick lingual frenulum (a membrane connecting the undersurface of the tongue to the floor of the mouth) or due to a frenulum, which attaches too near to the tip of the tongue.
Ankyloglossia is almost always a congenital disorder and its prevalence rate ranges from 0.04 to 6.8 percent. According to few investigators this condition may sometimes develop as a result of trauma. Recent study of Harris EF et al indicate that incidence of tongue tie may increase with maternal use of cocaine during pregnancy.
 
CLINICAL FEATURES
  • Ankyloglossia affects the males more frequently than females (2.6:1)
  • Although most affected individuals can perform tongue functions almost normally, the restricted tongue mobility in ankyloglossia may sometimes cause the following problems:
    • Speech disorders—patient cannot properly pronounciate certain consonants and diphthongs such as L, R, T, D, N, TH, SH, Z, etc.
    • Patient pronounciates the word “lemonade” as wemonade.
    • Infants feel difficulty in sucking breast milk.
    • Deformities in dental occlusion especially development of open bite and mandibular prognathism, etc.
    • Difficulty in swallowing food and maintaining oral hygiene.
    • Tension in the anterior lingual gingiva in tongue-tie may initiate some localized gingival or periodontal diseases near the site of frenal attachment (e.g. gingival recession and persistent gap between lower incisors).
    • Difficulty in kissing, licking one's lips, eating icecream cones and performing tongue tricks.
Ankyloglossia may occur sometimes in association with the following syndromes:
  • Ankyloglossum spurious syndrome
  • Vander Woudes syndrome
  • Fraser's syndrome
  • Rainbow's syndrome
  • Orofacial digital syndrome, etc.
 
TREATMENT
Partial ankyloglossia in most of the cases does not require any treatment, however in severe cases of ankyloglossia, surgical correction (frenulctomy) of the lingual frenulum is done to free the tongue. Sometimes, the offending frenulum may tear spontaneously resulting in freeing of tongue.
 
CLEFT TONGUE
Developmental disturbance may sometimes cause partial or complete cleft in the tongue. Although a complete cleft or bifid tongue is a rare congenital anomaly, however a partially cleft tongue is more frequently encountered.
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Cleft tongue usually develops due to partial or complete failure of union between the two lateral lingual swellings during embryogenesis. Incomplete cleft in the tongue develops due to failure of mesenchymal tissue proliferation that obliterates the groove.
Partial cleft tongue clinically exhibits a deep groove in the midline, while the bifid tongue shows a complete cleft along its long axis. Cleft tongue in most of the cases is an asymptomatic condition although sometimes irritation can be felt due to accumulation of food debri or microorganisms at the bottom of the cleft.
Sometimes, cleft tongue may occur as a feature of the orofacial digital syndrome, other features of this syndrome include frontal bossing, short upper lip with cleft, presence of thick fibrous brands in the lower anterior mucobuccal fold eliminating the sulcus and cleft of the mandibular alveolar process, etc.
 
FISSURED TONGUE (SCROTAL TONGUE)
Fissured tongue is a congenital developmental malformation; characterized by presence of numerous shallow or deep groves (fissures) on the dorsal and lateral surface of the tongue.
 
ETIOLOGY
The exact etiology for this condition is not known, however the following factors are often suspected:
  • Genetic defect (polygenic or autosomal mode of inheritance).
  • Vitamin deficiency
  • Trauma
  • It may be a normal variation of tongue architecture.
 
CLINICAL FEATURES
  • The overall worldwide prevalence rate of fissured tongue is about 7 percent (may be as high as 21 percent), prevalence in USA is about 2 to 5 percent.
  • Slightly more common among males.
  • Usually there is no clinical symptom in fissured tongue but collection of food debris and microorganisms in the fissures or groves may sometimes cause discomfort.
  • Similar discomfort may also be felt when fissured tongue occurs in association with geographic tongue.
  • The fissures or groves often radiate from a central groove on the dorsal surface in an oblique direction.
  • The large and deep fissures may be interconnected and they separate the dorsum of the tongue into multiple lobules.
  • The average depth of individual fissure is about 6 millimeter.
  • The disease often occurs in association with Melkersson-Rosenthal syndrome and some investigators believe that fissured tongue can be a feature of benign migratory glossitis.
 
HISTOPATHOLOGY
Histopathologically fissured tongue produces the following features:
  • There will be loss of filliform papilla from the surface mucosa.
  • Neutrophilic microabscess formation within the epithelium.
  • Hyperplasia of the rete-pegs and increased thickness of the lamina propria.
  • Mixed inflammatory cell infiltration in the connective tissue stroma.
 
TREATMENT
No treatment is required for fissured tongue except brushing of the tongue to eliminate the debris that irritates.
 
MEDIAN RHOMBOID GLOSSITIS
 
DEFINITION
Median rhomboid glossitis is an asymptomatic, elongated, erythematous patch of atrophic mucosa on the middorsal surface of the tongue.
 
ETIOPATHOGENESIS
In the past median rhomboid glossitis was thought to represent a developmental defect of the tongue, presumably arising as a result of persistence of the “tuberculum impar”on the surface of dorsum of the tongue.
During normal embryognesis, however the tuberculum impar should retrude and is overgrown by the lateral lingual swellings.
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In recent times, however several investigators believe that median rhomboid glossitis occurs due to chronic infection by Candida albicans.
 
CLINICAL FEATURES
Incidence: The average frequency of median rhomboid glossitis is about 0.2 percent among the general population.
Age: The condition is mostly seen among adults (30–50 years) and is rarely found among children.
Sex: Median rhomboid glossitis is seen more frequently among males (M: F-3: 1).
Site: The lesion is located immediately anterior to the foramen cecum and the circumvallate papillae, in the midline on the dorsurm of tongue (at the junction of the anterior two-third and posterior one-third areas).
 
PRESENTATION (FIGS 1.15A AND B)
  • The median rhomboid glossitis starts as a narrow, mildly erythematous area located along the median fissure on the dorsum of the tongue just anterior to the circumvalate papilla.
  • The lesion finally appears as a diamond or lozenge shaped area devoid papilla.
  • Clinically, the lesion is asymptomatic and it often remains unnoticed by the patient for many years.
  • It enlarges slowly and the fully developed lesion of median rhomboid glossitis reaches to a size of little less than 2 cm in diameter.
    zoom view
    Fig. 1.15A: Median rhomboid glossitis-I
  • The color of the lesion varies from pale pink to bright red and occasionally there is presence of a white halo.
  • The surface is usually smooth, flat or slightly raised and is sometimes fissured or lobulated.
  • In many cases, the lesion exhibits an erythematous and nodular hyperplasia characteristic of chronic hyperplastic candidiasis.
  • Some patients even develop a similar lesion on the midline of the palate just opposite to the tongue lesion and it occurs due to repeated contact with the infected tongue surface to the palate (kissing lesion).
  • Median rhomboid glossitis is usually asymptomatic but occasionally it may cause slight soreness or burning sensation.
  • The lesion is clinically suspicious and it is often mistaken for carcinoma of the tongue. Although dorsum of the tongue, where median rhomboid glossitis is located is not a frequent site for carcinoma of the tongue.
    zoom view
    Fig. 1.15B: Median rhomboid glossitis-II
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  • In some cases the disease may regress spontaneously.
 
DIFFERENTIAL DIAGNOSIS
  • Squamous cell carcinoma
  • “Gumma” of tertiary syphilis
  • Granular cell myoblastoma
  • Lingual thyroid nodule
  • Tuberculous granuloma
  • Deep fungal infection.
 
HISTOPATHOLOGY
Microscopically, median rhomboid glossitis presents the following features:
  • Mild to severe parakeratosis of the surface epithelium.
  • Loss of both filliform and fungiform papilla.
  • Thinning of the supra-papillary epithelium.
  • There may be presence of acanthosis with elongation of rete-ridges.
  • The rete-ridges may either divide or anastomose.
  • Superficial layer of the epithelium often shows neutrophilic infiltration, and often there is presence of numerous candidal hyphae.
  • The underlying connective tissue is usually very vascular and is infiltrated by chronic inflammatory cells.
  • Areas of irregular hyperplasia may be seen in the epithelium as a result of chronic inflammation in the underlying connective tissue.
  • On occasions, the epithelium may show features of dysplasia or individual cell keratinization due to the chronic fungal infection.
 
TREATMENT
No treatment is basically required for this lesion. Antifungal agents and antiseptic gurgles are used to relieve the erythema and irritation in the area.
 
LINGUAL VARICES
 
DEFINITION
A varix is a dilated, tortuous vein which is often subjected to increased hydrostatic pressure but is poorly supported by the surrounding tissue.
 
CLINICAL FEATURES
  • Varicosities can be observed in many oral locations like ventral surface of tongue, floor of the mouth, lips, buccal mucosa and the commissure, etc.
  • Among all these intraoral locations, ventral surface of tongue and floor of the mouth are the most common sites for oral varices.
  • Clinically lingual varices appear as small, round, purplish nodules, lateral to the sublingual vein, which is usually also deflected.
  • Lingual varices are common among people over the age of 50 years and the varices tend to become more conspicuous with advancing age.
  • Thrombosis can occur occasionally in these varicose veins, however only rarely there are any clinical symptoms.
  • In case of lingual varices, there is absence of any similar lesion in the skin and other mucosal locations.
  • The lesion interestingly has no bleeding tendency either.
  • Presence of lingual varices before the ages of 50 indicates premature ageing.
  • Lingual varices may occur in association with leg varicosities, however there is no relationship established between cardiopulmonary disorder and lingual varices.
  • Sometimes, lingual varices can be indistinguishable from hereditary hemorrhagic telangiectasia.
 
TREATMENT
No treatment is required for lingual varices.
 
GEOGRAPHIC TONGUE
 
DEFINITION
Geographic tongue is the multifocal, patchy irregular areas of depapillation of tongue characterized by frequent remissions and recurrences.
 
ETIOLOGY
The exact etiology of geographic tongue is not known, however patients often have a positive family history of the similar problem for 26generations. However, many investigators believe that emotional stress, asthma, eczema and allergy may also precipitate this condition.
 
CLINICAL FEATURES (FIGS 1.16 TO 1.18)
  • The condition occurs in about 1 to 2 percent of the population.
  • It can be seen among children as well as adults and there is a slight female predilection
  • Geographic tongue clinically presents multiple, irregular, well-demarcated, smooth patchy erythematous areas on the dorsum of the tongue with desquamation of the filliform papilla.
  • At the periphery, these lesions are often surrounded by a well-defined, slightly raised, yellowish-white, serpigenous line on the dorsum of the tongue.
  • Although, the filliform papillae are absent in the desquamated zone, the fungiform papillae remain present, which appear as few red dots, projecting from the surface.
  • The lesions heal centrally and spread centrifugally, and they may even sometimes involve the ventral surface of the tongue.
  • Remission of the initial lesion is always followed by fresh recurrent lesion at a new location over the tongue. Because of this tendency for migration of the lesion from one area to the other, it is often called “migratory glossitis” (Fig. 1.19).
  • Moreover, the benign migratory glossitis lesion mimics the continental outlines on the globe and this also makes frequent use of the term “geographic tongue” for the condition.
    zoom view
    Fig. 1.16: Geographic tongue-I
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    Fig. 1.17: Geographic tongue-II
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    Fig. 1.18: Geographic tongue-III
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    Fig. 1.19: Benign migratory glossitis (Geographic tongue-IV)
  • The condition is mostly painless and asymptomatic, however on few occasions, it may produce soreness or burning sensation 27(glossodynia) particularly during taking spicy or citrus foods.
  • Soreness of the tongue may be aggravated due to use of chemicals, e.g. chlorhexidine mouthwashes or tooth whiteners, etc.
  • The abnormal clinical appearance and the persisting nature of the lesion along with the associated soreness often makes the patient cancerophoveik.
  • Sometimes several lesions may coalesce together to produce a typical “scalloped pattern”.
  • Occasionally these lesions may occur in association with scrotal tongue or psoriasis.
 
HISTOPATHOLOGY
  • Geographic tongue microscopically shows hyperparakeratinization of the covering epithelium of tongue with loss of filliform papilla.
  • Intercellular edema and accumulation of neutrophil polymorphs (so called spongiotic abscess) is often seen in the superficial layers of the epithelium.
  • Mild inflammatory cell infiltration is present in the underlying connective tissue.
  • The condition is histologically similar to hyperplastic candidiasis, however candidal hyphae are absent.
 
DIFFERENTIAL DIAGNOSIS
  • Psoriasis
  • Lichenoid reactions
  • Reiter's syndrome
  • Chronic hyperplastic candidosis
  • Familiar dysautonomia.
 
TREATMENT
There is no specific treatment for geographic tongue. Heavy doses of vitamins may produce some results in few cases. Sometimes antihistaminic and local steroidal antinflammatory drugs are also used.
 
HAIRY TONGUE
 
DEFINITION
Hairy tongue is an unusual condition, which occurs due to hypertrophy of the filliform papilla of tongue along with loss of normal desquamation process. The abnormal hair-like growth of the papilla eventually leads to formation of a pigmented, thick, matted layer on the tongue surface often heavily coated with bacteria and fungi.
 
PATHOGENESIS
  • Normally the keratinized surface layers of the tongue papillae are continuously desquamated through friction of the tongue with food, rough surface of the palate and the upper anterior teeth. Following desquamation, tongue papillae are replaced by newer epithelial cells from below.
  • Lack of tongue movements due to local or systematic disease disturbs the regular desquamation process of the tongue papilla; especially the filliform papilla, which lengthens considerably and produces a hairy appearance on the tongue surface.
  • Such hypertrophied papillae are often coated with microorganisms and become discolored 28by retaining pigments from foods, medicines and chromogenic bacteria, etc.
 
CLINICAL FEATURES
  • Hairy tongue commonly affects the mid dorsum of the tongue.
  • Hypertrophy of the filliform papilla produces a thick matted layer on the dorsal surface.
  • Hairy tongue in extreme cases may produce a thick, leathery coating on the tongue surface and this condition is often known as “earthy or encrusted tongue”.
  • Hypertrophied filliform papilla may grow up to half a centimeter long, which often brushes the soft palate and produces gagging sensations.
  • Hairy tongue in many cases produces halitosis.
  • There can be irritation to the tongue due to accumulation of food debris and microorganisms.
  • Hairy tongue is often considered as the mirror of general health status since it is often associated with various systemic diseases.
 
DIFFERENTIAL DIAGNOSIS
  • Candidiasis
  • Leukoplakia
  • Lichen planas
  • Oral hairy leukoplakia.
 
TREATMENT
  • Cleaning and scraping of the tongue.
  • Application of topical keratolytic agents.
  • Consumption of yoghurt.
  • The affected tongue papilla often rapidly returns to normal when long-term antibiotics or other drugs are discontinued.
 
LINGUAL THYROID NODULE
 
DEFINITION
Accessory accumulation of functional thyroid gland tissue within the body of the tongue is called lingual thyroid nodule.
 
PATHOGENESIS
Embryologically thyroid gland develops as an endodermal downgrowth at the site of the foramen caecum. It then migrates inferiorly along the thyroglossal tract to its ultimate destination in the anterolateral surface of the trachea of the anterior neck. If all or part of the thyroid analogue fails to migrate, then lingual thyroid nodule develops, which is characterized by a mass of thyroid tissue on the midposterior dorsum of the tongue. Lingual thyroid nodule therefore represents a thyroid remnant in the site of the thyroid gland's origin.
 
CLINICAL FEATURES
  • Lingual thyroid nodule is predominantly seen in females and it becomes clinically apparent usually during puberty or adolescence.
  • In the tongue, thyroid tissue appears as a deep seated, nodular, exophytic mass, measuring about 2 to 3 cm in diameter and is located posterior to the foramen caecum mostly in the midline.
  • Sometimes, it can also be present as a smooth cystic or a vascular swelling.
  • Symptoms may vary, which include change of voice (dysphonia) bleeding, pain, difficulty in swallowing (dysphagia), respiratory obstruction (dyspnea) and a feeling of tightness in the throat.
 
HISTOPATHOLOGY
  • Histologically, most cases of lingual thyroid nodules are composed of normal mature thyroid tissue, although embryonic or fetal thyroid gland tissues may also be seen.
  • Occasionally, thyroid nodules may exhibit colloid degeneration or goiter.
  • Microscopic examination of human tongues removed at autopsy reveals remnants of the thyroid tissue within the tongue in as many as 10% cases, although there was no clinically evident thyroid nodule among them.
 
DIFFERENTIAL DIAGNOSIS
  • Thyroglossal tract cyst
  • Neoplasms.
 
DIAGNOSIS
Diagnostic procedures include:
  • Iodine-131 and technetium scans.
  • Preoperative biopsy from the thyroid nodule.
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TREATMENT
 
Surgical Excision
Before excision of a lingual thyroid nodule is planned, it must be determined if the patient has a normal functioning thyroid gland in the anterior neck with sufficient secretion to support the daily requirements.
Lingual thyroid nodules can be excised only if a normal thyroid gland is present in the neck. If the secretion from the thyroid gland in the neck is subnormal, then thyroid replacement therapy may be required.
 
THYROGLOSSAL TRACT CYST
 
DEFINITION
The thyroglossal tract cyst is an uncommon developmental cystic lesion arising from the embryonic remnants of the thyroglossal tract. It develops on the midline of the neck, anywhere between the base of the tongue above and the thyroid gland below.
 
ORIGIN
  • The thyroglossal tract cyst arises from the remnants of the embryonic thyroglossal tract, which had not become obliterated.
  • Initiation of the process of cyst development is triggered by infection of the lymphoid tissue in the area of the remnants, through drainage from upper respiratory tract infection.
  • The cyst can arise anywhere along the length of the thyroglossal tract, which extends from the foramen caecum of tongue to the thyroid gland; however most of the cysts (70 to 80% cases) develop below the hyoid bone on the midline of the neck, where the tract makes two distinct turns on its way to the thyroid gland.
 
CLINICAL FEATURES
  • The cyst occurs primarily in children and young adults.
  • It presents a slow enlarging, asymptomatic mobile swelling involving the midline of the anterior neck above the thyroid gland.
  • The firm cystic mass may vary in size from a few millimeters to several centimeters.
  • When seen in the region of the tongue, it appears as a dome-shaped compressible lesion.
  • The cyst moves during swallowing.
  • A small percentage of these cysts can occur within the tongue and these lesions may produce dysphagia.
  • If infected or inflamed a draining fistula may develop, which communicates between the cyst and the overlying skin surface.
  • Neoplasms including carcinomas have been reported to develop from these cysts.
 
HISTOPATHOLOGY
  • The cyst is usually lined by stratified squamous epithelium or ciliated columnar epithelium or transitional epithelium or a mixture of any of these epithelial types.
  • The lining epithelium of the cyst often occurs in association with follicles of the glandular thyroid epithelium.
  • Lymphoid aggregates, thyroid tissue, mucous glands and sebaceous glands, etc. are often present within the capsule of thyroglossal tract cyst.
  • In some cases the lining epithelium of the cyst or the remnants of the thyroglossal tract may undergo malignant transformation and results in the development of carcinoma.
 
DIFFERENTIAL DIAGNOSIS
  • Lingual thyroid nodule
  • Mesenchymal neoplasms
  • Dermoid cysts
  • Epidermoid cyst.
 
TREATMENT
Thyroglossal tract cyst should be surgically excised along with the tract. Rate of recurrence is very high. To minimize the recurrence of the cyst involving the hyoid area, it is sometimes recommended that the central portion of the hyoid bone and its associated remnants of thyroglossal tract be removed.
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ANOMALIES OF ORAL LYMPHOID TISSUE
 
REACTIVE LYMPHOID AGGREGATES
The oropharyngeal lymphoid tissue is primarily distributed in a circular arrangement called the “Waldeyer ring” in the posterior region of the mouth. It consist of three main masses of lymphoid tissue namely the paired palatine tonsils, the pharyngeal tonsils (adenoids) and the lingual tonsils.
Besides this, lymphoid tissues may also be found in a variety of intraoral locations like the buccal mucosa, soft palate, floor of the mouth and gingiva, etc.
Reactive hyperplasias may occur in lymphoid tissue in any of these locations. Lingual tonsil is one of the largest oral lymphoid aggregates and its common location is the posterior part of the tongue. It may extend anteriorly up to the region of the foliate papilla and reactive lymphoid hyperplasia of the lingual tonsil in this location is sometimes termed as “foliate papillitis”.
When inflamed, the lingual tonsils produce swelling, erythema of the overlying mucosa and pain or discomfort, etc. especially during swallowing. There can be diagnostic confusion if the involvement is unilateral rather than bilateral.
Sometimes, children and adolescents may have islands of extra pharyngeal lymphoid tissue called “oral tonsils” on either side of the lingual frenum and they appear as discrete, slightly elevated, reddish plaques in the floor of the mouth.
Oral tonsils consist of lymphoid aggregates, which exhibit germinal centers surfaced by nonkeratinized squamous epithelium with or without occasional crypts. It must be remembered that lymphoma the malignant neoplasm of the lymphoid tissue origin, can develop from any of the lymphoid tissue aggregates found in the oral cavity.
 
LYMPHOEPITHELIAL CYST (BRANCHIAL CYST)
 
DEFINITION
Lymphoepithelial cyst is the term used to describe cystic lesion previously classified as branchial cyst. It is a developmental cyst with an uncertain pathogenesis.
 
CLINICAL FEATURES
Age: Lymphoepithelial cysts occur during late childhood or early adulthood.
Sex: It occurs more frequently among males than females.
Site: The most common location is the lateral aspect of the neck, anterior to the sternomastoid muscle.
Intraoral lymphoepithelial cysts are uncommon lesions but whenever they occur, these lesions involve floor of the mouth in 50% cases and ventral and posterolateral surface of tongue in 40% cases. Other sites involved may be the soft palate, mucobuccal fold and anterior faucial pillars.
 
CLINICAL PRESENTATION
  • Lymphoepithelial cyst generally presents as an asymptomatic, circumscribed, movable swelling on the lateral aspect of the neck anterior to the sternomastoid muscle.
  • Intraorally it commonly appears as a small, slow enlarging, elevated, yellowish-pink nodule.
  • The cysts may be unilateral or bilateral and may be tendered on palpation.
  • A draining fistula may develop, which communicates between the cyst and the overlying skin surface.
  • The size of the cyst ranges from few millimeters to 1.5 to 2 cm in diameter.
  • Recent reports indicate that there is a marked increase in the incidence of lymphoepithelial cyst of the major salivary glands, among patients those, who are tested positive for HIV.
 
HISTOPATHOLOGY
  • Histologically the lesion consists of a cystic cavity lined by thin stratified squamous epithelium.
  • The cyst is generally embedded in a circumscribed mass of lymphoid tissue, which typically exhibits discrete follicles of the lymph node pattern.
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  • The capsule of the cyst also presents variable amount of connective tissue, being infiltrated by lymphocytes, plasma cells, macrophages and occasional multinucleated giants cells.
  • Cystic lumen is filled up with either a thin watery fluid or a thick gelatinous material containing desquamated orthokeratin, sloughed epithelial cells and lymphocytes, etc.
 
PATHOGENESIS
  • Lymphoepithelial cyst is probably derived from epithelium entrapped within lymphoid tissues of the neck during embryologic development of the cervical sinuses or second branchial clefts or pouches.
  • An alternate theory suggests that the epithelium in lymphoepithelial cyst might be derived from the ductal epithelium of salivary glands, which remained entrapped within the cervical lymph nodes during embryogenesis.
 
DIFFERENTIAL DIAGNOSIS
  • Inflammatory lesions
  • Teratoma
  • Warthins tumor
  • Dermoid cyst
  • Neoplasms of the minor salivary gland
  • Salivary lymphoma.
 
TREATMENT
The intraoral counterpart of lymphoepithelial cyst is treated by conservative surgery. Recurrence is usually rare.
 
ANGIOLYMPHOID HYPERPLASIA WITH EOSINOPHILIA (ALHE)
 
DEFINITION
This is a benign condition characterized by subcutaneous nodular aggregates of lymphocytes and eosinophils, regional lymphadenopathy and peripheral blood eosinophilia.
Similar findings were also noted under the heading of Kimura's disease, characterized by eosinophilic grannuloma of soft tissue and eosinophilic lymphofolliculosis. However, unlike angiolymphoid hyperplasia with eosinophilia, Kimura's disease has a distinct male predilection and is not associated with regional lymphadenopathy.
 
ETIOLOGY
  • A vascular proliferation along with intense inflammatory cell infiltration in the lesion suggests a reactive etiology for this condition.
  • A reactive immunologic cause has also been suggested as the disease shows increased serum IgE levels and deposition of IgE within the lymphoid follicles.
  • According to some investigators, candida albicans might be having some role in the initiation of this disease. Since, anti-candida albicans antibody can be demonstrated within the lesion and moreover, the condition improves after hyposensitization to these allergens.
 
CLINICAL FEATURES
Age: Mean age of occurrence is about 35 years.
Sex: More common among males.
Site: Although 85% of the lesions usually occur in the head and neck area, oral lesions one rare.
Lower lip is the commonest site.
 
PRESENTATION
  • The lesion clinically presents a slow enlarging, painless submucosal nodule.
  • It measures about 1.5 cm in diameter and is movable.
  • In about 40% cases eosinophilia is detected in peripheral blood examination.
  • Some of the patients may exhibit multiple lesions in the oral cavity.
 
HISTOPATHOLOGY
  • Microscopically angiolymphoid hyperplasia with eosinophilia reveals a circumscribed lesion, which is grossly separable from the surrounding tissue.
  • A nodular mass of hyperplastic lymphoid tissue is seen with well-defined lymphoid follicles.
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  • Patchy areas of inflammatory infiltrates comprising of lymphocytes, eosinophils and macrophages are seen.
  • Proliferating blood capillaries with plump endothelial cells are often noticed within the inflammatory zone.
 
DIFFERENTIAL DIAGNOSIS
  • Minor salivary gland neoplasm
  • Mucocele
  • Lipoma
  • Schwannoma
  • Eosinophilic granuloma.
 
TREATMENT
  • Surgical excision
  • Intralesional steroid therapy may produce some response.
Recurrence is rare.
 
ANOMALIES OF THE SALIVARY GLAND
 
DEVELOPMENTAL ANOMALIES INVOLVING ORAL HARD TISSUES
 
ABNORMALITIES OF TEETH
Teeth develop from the cooperative interaction of two germ layers: a) ectoderm and b) ectomesenchyme. The tooth development begins at about the sixth week of the intrauterine life when few cells of the oral ectoderm undergo proliferation and eventually result in the formation of the dental lamina. The odontogenic cells (tooth forming cells) emerge from dental lamina and the later event constitutes the beginning of tooth development. The enamel develops from the ectoderm while the dentin, pulp, cementum, periodontal ligament and alveolar bone develop from the ectomesenchyme. The development of tooth occurs in several stages, namely the
  1. The stage of initiation (bud stage).
  2. The stage of proliferation (cap stage).
  3. The stage of histodifferentiation (bell stage).
  4. The stage of morphodifferentiation.
  5. The stage of apposition.
  6. The stage of calcification and
  7. The stage of eruption.
Developmental anomalies may occur during any of these developmental stages of tooth formation, which are, manifested clinically in the later life once the tooth is fully formed. These anomalies of tooth can occur either due to genetic factors or due to some environmental factors, however in few instances, even both of these factors could be involved together to cause some defects in the teeth. Developmental disturbances can results in the formation of some peculiar or strange looking teeth which exhibit mild to extreme variations from the normal teeth.
 
DISTURBANCE IN SIZE OF TEETH
 
MICRODONTIA
 
DEFINITIONS
Microdontia is the condition in which one or more teeth are smaller than normal in size. When all teeth are involved, it is called generalized microdontia and when only a few teeth are involved it is called localized or focal microdontia.
It is important to note that size of both teeth and the jaws are almost always genetically determined. However, wide variations are often seen in the ratio of tooth size and jaw size. Therefore alterations in the size of tooth are often proportionately variable to the size of the jaw.
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TYPES OF MICRODONTIA
 
True Generalized Microdontia
  • When all the teeth in both arches are uniformly and measurably smaller than normal the condition is known as true generalized microdontia.
  • This is an extremely uncommon condition and can be seen in pituitary dwarfism.
  • True generalized microdontia can also be associated with other congenital defects like down syndrome and congenital heart disease, etc.
 
Relative Generalized Microdontia
  • Relative generalized microdontia is the condition in which teeth of normal size may look smaller, if they are placed in an abnormally large maxilla or mandible.
  • In such cases larger size of the jaws give an illusion of microdontia although the teeth are not really small.
  • Relative microdontia often exhibits spacing in between the teeth.
 
Focal Microdontia
  • When one or two teeth in the jaw are measurably smaller in size while rest of the teeth are normal, the condition is called focal microdontia.
  • Microdontia involving one or two teeth in the dental arch is far more common than the generalized types.
  • The affected teeth are often present symmetrically in the jaw and in addition to being miniature in size, these teeth often exhibit alteration in their shape as well.
  • Maxillary lateral incisors and maxillary third molars are the most frequently involved teeth in focal microdontia.
  • When maxillary lateral incisors are involved, the teeth often appear “cone” or “peg” shaped and are often designated as peg laterals. These teeth often give a peculiar facial expression of the patient.
  • These peg laterals carry an autosomal dominant type of inheritance pattern and tend to be familial.
  • Maxillary and mandibular second premolars may sometimes exhibit microdontia.
  • Supernumerary teeth are almost always smaller than the normal teeth and are often conical in shape.
  • There are certain situations in which smaller teeth can be found in the mouth, although these conditions may not be truly developmental in nature.
Examples:
  • Smaller teeth can be seen in the affected side of the jaw in facial hemiatrophy.
  • In case of gemination or twinning one single tooth germ splits into two, during development and gives rise to two separate teeth, which are always smaller than normal.
  • Small, conical teeth are often seen in hereditary ectodermal dysplasia.
  • Multiple miniature teeth can be found in compound odontomes and in teratoma.
  • A retained deciduous tooth within the permanent dentition may give an illusion of focal microdontia.
 
CLINICAL SIGNIFICANCE OF MICRODONTIA
  • In microdontia, teeth are often spaced which may be disturbing cosmetically.
  • There may be difficulty in speech and taking food.
  • When shapes of these teeth are also altered along with microdontia (e.g. peg laterals), it will require immediate correction.
  • Crown and bridge prosthetic work may be required for esthetic rehabilitation of such teeth.
 
MACRODONTIA
 
DEFINITION
Macrodontia is a condition in which teeth in the jaws are measurably larger than normal in size. This is a far less common anomaly of tooth than microdontia.
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TYPES OF MACRODONTIA
Macrodontia can be of three types, which are as follows:
  1. True generalized macrodontia: When all the teeth in both arches are measurably larger than normal, the condition is termed as true generalized macrodontia. It can be seen infrequently in case of pituitary gigantism.
  2. Relative generalized macrodontia: Relative generalized macrodontia is used to designate a condition in which the normal sized teeth appear somewhat larger because of the smaller jaw size. In such cases the dental arches often exhibit crowding of teeth.
  3. Focal or localized macrodontia: Localized macrodontia is occasionally seen on the affected side of the mouth with hemifacial hypertrophy. Macrodontia of individual tooth is a rare entity and it mostly affects the incisors (Fig 1.20). However focal macrodontia should not be confused with “fusion” of teeth, (in which two adjacent teeth unite together to form a single large tooth).
 
DISTURBANCE IN NUMBER OF TEETH
 
ANODONTIA
 
DEFINITION
Anodontia can be defined as a condition in which there is congenital absence of teeth in the oral cavity.
 
TYPES
Anodontia can be of two types:
  1. Complete or total anodontia: Congenital absence of all teeth.
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    Fig. 1.20: Macrodontia of upper central incisor
  2. Partial anodontia or oligodontia or hypodontia: Congenital absence of one or few teeth.
Anodontia can further be divided into the following types:
True anodontia: True anodontia occurs due to failure of development or formation of tooth in the jawbone.
Pseudoanodontia: Refers to the condition in which the teeth are actually present within the jawbone but are not clinically visible in the mouth, as they have not erupted. Examples of pseudoanodontia can be impacted teeth or submerged teeth, etc.
False anodontia: False anodontia is the condition in which the teeth are missing in the oral cavity because of their previous extraction or exfoliation.
 
Complete or Total Anodontia
Total anodontia is a rare condition in which there is neither any deciduous tooth nor any permanent tooth present in the oral cavity.
  • It is usually seen in association with hereditary ectodermal dysplasia. This condition is usually inherited as an x-linked recessive trait and although it primarily affects males but an autosomal dominant form can occur, which affects females.
  • There will be inherited defects in the ectodermally derived structures of the body such as hair, sweat gland, teeth and salivary gland, etc. with a typical inability to regulate body temperature.
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    zoom view
    Fig. 1.21: Complete (total) anodontia
  • Although complete anodontia is a common feature of hereditary ectodermal dysphasia, however in many cases the cuspids are present in the mouth and the teeth are often malformed with conical crowns.
  • Complete anodontia sometimes occur among children those who have received high doses of radiation to the jaws as infants for therapeutic reasons (Fig. 1.21).
High doses of radiation cause destruction of tooth germs resulting in complete failure of tooth formation in future, moreover even a very lower dose may cause cessation of odontogenesis.
 
Partial Anodontia
Partial anodontia is a much more common phenomenon and is characterized by congenial absence of one or few teeth (Fig. 1.22). This condition is also known as hypodontia or oligodontia. The condition is more commonly seen in permanent dentition.
In partial anodontia, when a deciduous tooth is congenitally absent it is very much likely that its permanent successor will also be missing thereby suggesting some genetic influence.
 
Incidence Rate
Incidence rate of partial anodontia varies in different population groups but near about 35% of the general population will have at least one congenitally missing tooth.
A familial tendency for congenitally absent teeth is a well-recognized phenomenon.
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Fig. 1.22: Partial anodontia
 
Commonly Missing Teeth in Partial Anodontia
  • In partial anodontia, any tooth can be congenitally missing, however it is often noticed that certain teeth tend to be absent more often than others.
  • The third molars (any one or all four of them) are the most frequently observed congenitally missing teeth.
  • Maxillary lateral incisors and mandibular premolars are the next most common group of teeth, which are often congenitally absent.
  • When deciduous teeth are involved it partial anodontia, the maxillary lateral incisors are most likely to be affected.
  • It should be noted that mandibular first molars and mandibular lateral incisors are the teeth, which are least likely to be missing during anodontia.
 
Diseases or Clinical Conditions to be Commonly Associated with Partial Anodontia
Incontinentia pigmenti: This hereditary disorder is characterized by diffuse slate-gray macules of the skin, white lesions of the oral mucosa, skeletal, ocular and neuralgic disturbances; and partial anodontia with delayed eruption of tooth.
Hyalinosis cutis mucosae: This disease is characterized by pathologic accumulation of glycoprotein in the body and it often manifests with the following features: Hoarseness of voice, vesicular skin lesions, nodular or papillary lesions of the oral mucosa, intracranial calcifications and hypodontia.
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Mandibulo-Oculo-Facial dyscephaly: This disease is also known as Hallermann-Steriff syndrome and is characterized by brachycephaly, frontal bossing, microstomia, TM joint disturbance, blue sclera, hypotrichosis and hypodontia with retention of deciduous teeth.
Chondroectodermal dysplasia: This hereditary disorder is characterized by developmental abnormalities in both ectodermal and mesodermal tissues. Although it shares few features with hereditary ectodermal dysplasia but both are different pathologic entities.
Chondroectodermal dysplasia clinically manifest with the features like—defective nails and hair, normal sweat glands, congenital absence of numerous teeth, fusion of the upper lip to the anterior maxillary alveolar ridge, short limbs with polydactyly and congenital heart defects, etc.
Book's syndrome: This syndrome is commonly associated with localized hypodontia and its other features include—premature whitening of hairs and hyperhydrosis of the palms and soles.
Rieger's syndrome: It is an autosomal dominant hereditary disorder and it shows oligodontia or hypodontia with serious ophthalmic defects.
 
SUPERNUMERARY TEETH
 
DEFINITION
Presence of any extra tooth or teeth in the dental arch, in addition to the normal series of teeth is known as supernumerary teeth. The condition is also known as hyperdontia or polydontia. Supernumerary teeth occur less frequently than the anodontia. These teeth may erupt spontaneously in the oral cavity or they may be impacted and are detected incidentally during routine radiographic examinations.
 
ETIOLOGY OF SUPERNUMERARY TEETH
  • Heredity, these are more commonly seen among the family members of the affected individual as compared to the general population.
  • Dichotomy (division into two) of the tooth bud.
  • Localized conditioned hyperactivity of the dental lamina.
  • Fragmentation of the dental lamina during development of cleft lip and cleft palate.
 
MODE OF FORMATION
  • A supernumerary tooth may develop either from an accessory tooth bud in the dental lamina and can be seen in any part of the dental arch.
  • It may develop due to spitting of a regular normal tooth bud during the initial phase of odontogenesis.
  • The supernumerary tooth can occur in both males as well as in females.
  • A supernumerary tooth may resemble the corresponding tooth (i.e. where they are located) but in many cases it may have a conical shape. Therefore, morphologically sometimes these teeth may look like molars, premolar or like incisors, etc. depending upon their location or sometimes they may have an altogether different morphologic appearance. However in most of the cases these extra teeth are much more smaller in size (miniature form) than their normal counterparts.
 
COMMON LOCATIONS
  • Supernumerary teeth can occur in any location but they often have a predilection for certain sites.
  • These are far more common in maxilla (90%) as compared to mandible.
  • Supernumerary teeth are more often seen in maxillary permanent dentition and are rarely seen in deciduous dentition.
 
TYPES OF SUPERNUMERARY TEETH
 
According to the Site
Supernumerary tooth developing or erupting at certain sites may be known by certain special terms and these are as follows:
 
Mesiodens
Mesiodens are the most common of all supernumerary teeth and these are located in the midline, on the palatal aspect, between the roots of two upper central incisors. These teeth can be either impacted or inverted or may be horizontal in orientation. Mesiodens develop before or at the time of development of the upper central incisor teeth.
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Distomolars
Distomolars are supernumerary molars, which are usually located on the distal aspect of the regular molar teeth in the dental arch.
 
Paramolars
These are also extra molar teeth, which are usually located either in the buccal or in the lingual aspect of the normal molars. Both distomolars and paramolars are often known as the fourth molars.
 
Extra lateral incisors
Although rare, extra lateral incisor teeth can be present and they are more common in the maxillary arch.
Most of the supernumerary teeth exhibit conical crowns; they may be either single or multiple in numbers and are either erupted or impacted.
 
According to Morphology
According to their morphological characteristics supernumerary teeth can be classified into the following types:
Conical type: These supernumerary teeth are small, often peg-shaped and mostly seen in the permanent dentition, i.e. mesiodens.
Tuberculate type: These supernumerary teeth posses more than one cusp or tubercle, are often barrel-shaped and may be invaginated. These are more commonly seen in the incisor area, on the palatal aspect of upper incisors and the teeth are often impacted.
Supplemental type: This type of supernumerary tooth shows duplication (similarity in appearance) of any normal tooth in the dental arch. Most common example is the one which resembles permanent maxillary lateral incisor.
Odontome associated: These supernumerary teeth occur in association with compound odontome as multiple miniature teeth inside the tumor.
 
INCIDENCE RATE OF SUPERNUMERARY TEETH
  • 2.1 percent in permanent dentition.
  • 0.8 percent in deciduous dentition.
 
CLINICAL FEATURES
  • In many cases, the supernumerary teeth remain clinically asymptomatic.
  • The supernumerary tooth may develop as a single one or they may be multiple in numbers, moreover these teeth can be either unilateral or bilateral.
  • The extra tooth may be either erupted or impacted in the oral cavity and both upper and lower jaw can be affected.
  • Supernumerary teeth may sometimes produce crowding or malocclusion and they often cause cosmetic problems.
  • They may cause rotation, protrusion or displacement of the normal teeth.
  • In many instances, these teeth are responsible for either failure of eruption or delayed eruption of other normal teeth.
  • In many cases these extra teeth may be either directly or indirectly responsible for increased caries incidence and periodontal problems.
  • Multiple supernumerary teeth (most of them are impacted), may occur in association with conditions like cleidocranial dysplaisa or Gardener's syndrome etc.
  • Supernumerary teeth can occur in the deciduous dentition and whenever they occur, the most common one is the maxillary lateral incisor.
  • Supernumerary teeth may initiate the development of some pathological conditions in the jaw, e.g. dentigerous cyst may develop in relation to an impacted supernumerary tooth.
  • Supernumerary teeth may sometimes occur in association with cleft palate; moreover presence of these extra teeth often creates problem in the surgical correction of cleft palate itself.
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  • Presence of supernumerary teeth may create problems in orthodontic correction of teeth and also in the placement of implants in the jaw.
  • These extra teeth often cause root resorption of the neighboring normal teeth in the jaw.
  • In mandible the most common supernumerary teeth are the extra premolars, although fourth molars or additional incisors are also occasionally found.
 
TREATMENT
  • Supernumerary teeth are mostly nonfunctional and they should be extracted especially if they are causing displacement or delayed eruption of the normal teeth.
  • Impacted supernumerary teeth should also be removed surgically since they can interfere with normal tooth alignment or can develop some pathology.
 
DISTURBANCES IN ERUPTION OF TEETH
Eruption is the process in which the developing teeth move from their area of formation inside the jaw into the oral cavity to become a part of the dental arch.
The eruption time for both deciduous and permanent teeth often vary among different persons. Therefore, it is sometimes difficult to assess the exact eruption time for a particular tooth in any given individual. However, when the eruption of tooth occurs in the mouth either much before or long after the expected normal time, then we can consider that an eruption abnormally exists.
 
TYPES OF ERUPTION ABNORMALITIES
  • Premature eruption
  • Delayed eruption
  • Impacted tooth
  • Embedded tooth
  • Eruption sequestrum.
 
PREMATURE ERUPTION
 
DEFINITION
Premature eruption can be defined as a situation when a tooth erupts into the oral cavity much before its normal time of eruption.
 
TYPES
  • Natal teeth: These are erupted deciduous teeth present at birth.
  • Neonatal teeth: These are deciduous teeth, which erupt during the first 30 days of life.
 
ETIOLOGY
The exact etiology of premature eruption is not known, however a familial pattern is sometimes noticed.
 
COMMONLY INVOLVED TEETH
  • Premature eruption usually involves only one or two teeth, most commonly the deciduous mandibular central incisors.
  • Natal or neonatal teeth are not supernumerary teeth, in fact they are part of the normal component of deciduous dentition and therefore these teeth should be preserved in the mouth if possible.
  • Premature eruption of permanent teeth may occur as a result of loss of preceding deciduous teeth at a much earlier time. It is often seen that when a single deciduous tooth exfoliates prematurely, its permanent counterpart erupts much before its normal time of eruption.
  • However, in hyperthyroidism the entire permanent dentition may erupt prematurely.
 
DELAYED ERUPTION
 
DEFINITION
Delayed eruption refers to the first appearance of the teeth in the oral cavity at a much later time than what is normally expected.
This is a relatively uncommon phenomenon and can involve both deciduous as well as the permanent dentition.
 
IDIOPATHIC DELAYED ERUPTION
In many cases however the exact cause for the delayed eruption is not clearly known. Delayed eruption of permanent teeth may occur due to the same local or systematic factors, which are responsible for the delayed eruption of deciduous teeth.
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IMPACTED TEETH
 
DEFINITION
Impaction is defined as the cessation of eruption of tooth caused by a clinically and radiographically detectable physical barrier in the eruption path or by an ectopic position of the tooth.
 
FACTORS CAUSING IMPACTION OF TOOTH
  • Micrognathia: A smaller jaw cannot afford to accommodate all the teeth supposed to be present in the arch, hence few of them may become impacted.
  • Malocclusion: Abnormal orientation of some teeth, which have erupted at an earlier age may sometime block the normal pathway for the eruption of few other teeth which are due to erupt later.
  • Rotation of teeth: Rotation results in eruption of a tooth at a different angulation in the jaw, which results in impaction of such tooth.
  • Premature exfoliation of deciduous teeth: It causes partial closure of space in the alveolar ridge.
  • Retained deciduous tooth: An abnormally retained deciduous tooth may resist the eruption of its permanent counterpart and the later may sometimes become impacted.
  • Supernumerary tooth: A supernumerary tooth may sometimes obstruct the pathway for eruption of other teeth resulting in their impaction. On the other hand, in many instances a supernumerary tooth itself may remain impacted due to lack of space for eruption.
  • Odontogenic cyst (e.g. keratocyst): It may act as a physical barrier and result in the impaction of tooth in the region.
  • Odontogenic tumor (e.g. odontome): It also may results in impaction of a tooth by acting as physical barrier in the path of eruption.
  • Cleft palate: In many cases, teeth may be impacted in the area of cleft palate.
  • Nonodontogenic tumors or cysts: These lesions may sometimes cause impaction of tooth as they obstruct the path of eruption of a tooth.
  • Cleidocranial dyplasia: This disease entity is often associated with multiple impactions.
  • Gardner's syndrome: It is also associated with multiple impacted teeth.
  • Amelogenesis imperfecta: Impacted teeth are also seen in various forms of amelogenesis imperfecta.
  • Syndrome associated with enamel defects: Impacted teeth can also be seen in case of syndrome associated enamel defects such as Ameloonychohypohydrotic syndrome and Trichodento-osseous syndrome, etc.
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TEETH WHICH MAY BE COMMONLY IMPACTED
  • Although, virtually any tooth can be impacted, the commonest impacted teeth are the mandibular and maxillary third molars.
  • The next common teeth are the mandibular second premolars and maxillary canines.
  • The supernumerary teeth can be impacted in many cases.
 
CLASSIFICATION OF IMPACTION
Impactions are commonly classified in the following manner:
Mesioangular impaction: This is a common type and in this case the long axis of the impacted tooth is inclined mesially (towards midline of dental arch) as compared to the remaining teeth in the jaw.
Distoangular impaction: In this type the long axis of the impacted tooth is distally inclined (away from the midline of dental arch).
Horizontal impaction: Horizontally impacted teeth lies parallel to the long axis of the jawbone.
Vertical impaction: In this case the impacted tooth stands vertically but it occlusal plane is far below the occlusal plane of other erupted teeth.
Completely impacted tooth: When an impacted tooth is totally enclosed by bone, it is called a completely impacted tooth.
A completely impacted tooth does not communicate with the oral cavity and is therefore not susceptible to caries or infection.
Submerged tooth: when there is cessation of eruption of a deciduous tooth after gingival emergence, it is called a submerged tooth. The occlusal surface of the tooth lies above the gingiva but below the occlusal plane of the remaining teeth.
Embedded tooth: When an individual tooth fails to erupt for no apparent cause, it is called an embedded tooth. The tooth lies below the gum line and there is no physical barrier present as may be seen in case of impaction.
Partially impacted tooth: When an impacted tooth is partly surrounded by bone and partly by soft tissue, it is considered as a partially impacted tooth.
Partially impacted teeth often communicate with the oral cavity via an inconspicuous periodontal pocket and therefore make the tooth vulnerable to caries or infections.
 
RADIOGRAPHIC FEATURES OF IMPACTED TEETH
Radiographs are very much essential for determining the various aspects of an impacted tooth:
  • Radiograph helps in determining the types of impaction (mesioangular or distoangular or vertical types, etc.)
  • It also helps to determine the position of the root apex of the impacted tooth in relation to the mandibular canal in case of lower teeth.
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  • It can reveal the curvature of the root of the impacted tooth.
  • Presence of resorptions (either root or crown) of the impacted tooth as well as dental caries, etc. may be detected by radiographs.
  • Radiographs can help to detect any pathology, e.g. abscess, tumor or cyst, etc. which are associated with an impacted tooth.
 
CLINICAL FEATURES OF IMPACTION
Impacted teeth may sometimes remain innocent for the entire life but in many cases they can produce some clinical symptoms, which are as follows:
  • Infection with associated pain and swelling.
  • Trismus and extraoral sinus formation.
  • Malocclusion and crowding in the dental arch.
  • Root resorption of the adjacent erupted teeth.
  • Predisposition to dentigerous cyst development.
  • May precipitate the development of tumor in the jaw.
  • Increases the possibility of periodontal problems.
  • Impacted teeth often favor food impaction and therefore can result in development of caries in the adjacent teeth.
  • External resorption of the impacted tooth.
  • Sometimes, impacted tooth can be found within the maxillary antrum.
  • In many cases root of the impacted tooth may be present at a close proximity to the mandibular canal and in such cases possibility of damage to the neurovascular bundle is very high at the time of removal of such teeth.
  • Presence of impacted tooth may weaken the jawbone in some cases and there is an increased possibility of fracture of this bone when subjected to trauma.
  • Impacted teeth may predispose to the development of osteomyelitis, cellulites and space infections, etc.
 
TREATMENT
Treatment modalities vary depending upon the individual impacted tooth and the specific circumstances.
  • Most impacted molars are surgically extracted. However special efforts are made to save the impacted maxillary canines since these are cornerstones of the upper dental arch.
  • If the impaction is caused by any physical factor such as a cyst, tumor or any supernumerary teeth, the treatment procedure must include elimination or removal of those lesions.
 
ERUPTION SEQUESTRUM
It is a small fragment of necrosed bone, which is sometimes seen overlying an erupting tooth. This type of bone fragment is probably detached from the alveolar ridge during the emergence of the erupting tooth outside gingiva. Lack of complete resorption of the overlying alveolar bone during tooth eruption is the cause of formation of eruption sequestrum. Clinically it may cause pain, soreness and difficulty in taking food, etc.
 
DISTURBANCES IN THE SHAPE OF TEETH
 
GEMINATION (TWINNING)
 
DEFINITION
Gemination is a developmental anomaly characterized by a partial cleavage in a single tooth germ resulting in the formation of an anomalous tooth with two partially separated crowns and one root. It is therefore an abortive attempt at division of one tooth into two.
The term twinning refers to the complete and equal division of a single tooth germ that result in the formation of one normal and one supernumerary tooth.
  • Gemination affects both deciduous as well as the permanent dentition.
  • There is no sex predilection.
  • Geminated tooth often shows doubling of both the crown as well as the root.
  • Gemination mostly affects the deciduous mandibular incisors and permanent maxillary incisors.
  • Clinically the geminated tooth reveals either an extremely widened crown or their can actually be an indentation or groove delineating the two crown forms.
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PATHOGENESIS
Gemination is the result of either “schizodontism”—the splitting of a tooth germ during development or it can result from “synodontism”, the fusion of a regular tooth bud with one supernumerary tooth bud.
Gemination often clinically resembles another developmental anomaly called “fusion”. Gemination can be distinguished from fusion by the fact that full complement (number) of teeth are present in the dental arch in case of gemination (one extra tooth is present in case of twinning) where as in case of fusion one regular tooth is missing from the dental arch.
Problems in gemination: The following problems can occur due to gemination of tooth:
  • Tooth malposition
  • Spacing of teeth
  • Dental arch asymmetry
  • Cosmetic problems
  • Periodontal problems
  • Increased caries susceptibility
  • Disturbance in the eruption of adjacent teeth.
 
TREATMENT
Since gemination produces some cosmetic disturbance, construction of esthetic crown or bridge may be necessary for cosmetic rehabilitation.
 
FUSION
 
DEFINITION
Fusion can be defined as the union of two adjacent normally separated tooth germs at the level of dentin during development (Figs 1.23 and 1.24). It results in union of two teeth by dentin and enamel, pulp chambers are often shared or they may be separate.
Fusion results in one anomalous large tooth formation in place of two normal regular sized teeth and the tooth have either a single enlarged root or two roots. One of the most important criteria for fusion is that the fused tooth must exhibit confluent dentin.
 
CAUSES OF FUSION
  • Hereditary cause.
  • Trauma during development of teeth.
    zoom view
    Fig. 1.23: Fusion of teeth-I
    zoom view
    Fig. 1.24: Fusion of teeth-II
  • Physical force or pressure causing contact between two adjacent tooth germs.
 
CLINICAL FEATURES
  • Both deciduous as well as permanent teeth can be affected in case of fusion, although it is more common in deciduous teeth.
  • Fusion can occur between two normal teeth or between one normal and one supernumerary tooth.
  • Fusion can occur bilaterally in the jaw.
  • In both dentitions, the incisor teeth are more frequently affected.
  • There is no sex prediliction in case of fusion.
  • Fusion can be complete or incomplete and its extent will depend on the stage of odontogenesis at which the fusion took place.
  • In case of fusion between two adjacent deciduous teeth, the resultant fused tooth may not exfoliate normally and thus may interfere with the eruption of the permanent successor.
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COMPLETE FUSION
If fusion begins before the calcification of the tooth has occurred, then the fusion will be complete and the fused tooth crown will incorporate all components of both the participating teeth including their enamel, dentin, cementum and the pulp.
 
INCOMPLETE FUSION
If fusion begins in the later stages of tooth development, then the fused tooth may exhibit separate crowns and the fusion process may be limited to the roots only, with pulp canals either fused or separate. This condition is called incomplete fusion.
 
RADIOGRAPHIC FEATURES (FIG. 1.25)
Radiographs can be immensely helpful in determining the complete or incomplete fusion. Complete fusion gives rise to the development of a single large tooth with single root canal.
 
CLINICAL COMPLICATIONS
Fusion often Creates the Following Problems:
  • There can be spacing or diastema formation between the teeth.
    zoom view
    Fig. 1.25: Radiograph of fusion of teeth
  • There can be crowding of teeth in the arch, especially when fusion occurs between one normal and one supernumerary tooth.
  • Esthetic problems.
  • Periodontal complication.
  • Fusion can be differentiated from gemination by counting the number of teeth in the arch, since in case of fusion there will be one tooth less in the dental arch. However, in case of twining there will be one extra tooth in the dental arch.
 
TREATMENT
Depending upon the extent of clinical problem, fabrication of cosmetic crowns or bridges may be necessary for esthetic recovery in case of fusion.
 
CONCRESCENCE
 
DEFINITION
Union of the roots of two or more adjoining completely formed teeth along the line of cementum is known as concrescence.
This is a type of fusion, which is limited only to the roots of the teeth and it occurs due to deposition of cementum after the root formation of the involved teeth have been completed.
 
ETIOLOGY
  • Traumatic injury
  • Crowding of teeth
  • Hypercementosis associated with chronic inflammation.
 
PATHOGENESIS
The condition is thought to occur as a result of traumatic injury to the jaw, which causes loss of interdental bone and brings the roots of the neighboring teeth in close proximity to one another. Finally such fusion occurs between the roots of two or more such separate teeth due to deposition of cementum between them.
 
IMPORTANT FEATURES
  • Concrescence represents an acquired defect and it can occur in both erupted and unerupted teeth.
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  • There is no sex predilection.
  • In case of concrescence, union never takes place between the enamel, dentin or the pulp of the involved teeth except cementum.
  • In concrescence, the union mostly occurs between two teeth, however there may be cases where union occurs between multiple teeth.
  • Permanent maxillary molars are more often affected than any other teeth.
  • Concrescence also frequently occurs between one normal tooth and one supernumerary tooth.
  • Concrescence rarely involves the deciduous dentition.
  • Concrescence frequently occurs in those areas of the dental arch where the roots of the neighboring teeth are anatomically placed close to one another (e.g. between maxillary second and third molars).
  • Concrescence can be more complicated if the union occurs between one erupted tooth with an impacted tooth.
  • Clinically, the condition can not be detected since the union takes place in the root areas of tooth; the crowns of the involved teeth look normal and unsuspecting.
 
RADIOGRAPHIC FEATURES
Radiographs reveal obliteration of periodontal ligament space in the interradicular areas of teeth.
 
CLINICAL SIGNIFICANCE
  • The clinical significance of concrescence relates primarily to its radiographic diagnosis before planning a tooth extraction. Because in undiagnosed cases attempted extraction of the affected tooth may cause trauma to the jaw or may result in removal of many teeth instead of one.
 
DILACERATION
 
DEFINITION
Dilaceration is a developmental disturbance in the shape of tooth, it refers to a severe angulation or a sharp bend or curve in the root or crown of a formed tooth.
The bend is mostly located at the junction between the crown and the root of the tooth; in other cases it may be located at the mid portion of the root or sometimes even near the root apex.
In dilacerations the bend in the tooth sometimes can be as stiff as 90 degree. When the bend is restricted only to the root portion of the tooth the condition is known as “flexion”.
 
PATHOGENESIS
The condition probably occurs subsequent to trauma or due to any other defect of development, which alters the angulation of the tooth germ during the root formation.
  • It is generally believed that trauma to a partially calcified tooth may cause displacement of the hard calcified portion of the tooth away from its normal axis and later on, the unclassified portion develops with an unusual angulation.
  • In dilacerations, the location of the curve or bend on the tooth depends on the extent to which the permanent tooth was formed at the time of injury.
  • Injury to a deciduous tooth may push a partly formed permanent tooth further down apically into the jaw and as a result a bend in the permanent tooth develops.
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  • Some investigators believe that trauma is not always an essential factor for the development of dilacerations and according to them the anomaly occurs as a result of continued root formation during a curved or tortuous path of eruption.
  • In some cases the cause of the defect is idiopathic.
 
CLINICAL FEATURES
  • Dilaceration may involve any tooth belonging to either the deciduous as well as the permanent dentition.
  • There is no sex predilection.
  • Sometimes dilaceration at the coronal portion of the tooth is observed.
  • The tooth typically looks “hook-shaped” due to the bending in the root.
Dilaceration in a tooth can easily be detected by radiographs and care should be taken during extraction of such teeth. Since these teeth are more prone to fracture during removal.
 
TAURODONTISM
 
DEFINITION
Taurodontism or “bull-like” tooth is a peculiar developmental condition in which, the crown portion of the tooth is enlarged at the expanse of its roots.
 
PATHOGENESIS
The condition probably occurs due to failure of the Hertwig's root sheath to invaginate at the proper horizontal level during tooth development.
 
CLINICAL FEATURES
  • The affected tooth in taurodontism exhibits large crown with elongated pulp chamber and short rudimentary root.
  • The affected tooth is usually rectangular in shape with minimum constriction at the cervical area; moreover the furcation area of the tooth is more apically placed than normal.
  • The tooth often has a greater apico-occlusal height and the level of furcation of the roots is situated much below the cervical area.
  • In taurodontism the affected tooth generally exhibit certain morphologic changes.
  • This defect can involve both sexes equally.
  • Taurodontism commonly affects the multirooted permanent molars and sometimes the premolars. It is rarely seen in the primary dentition.
  • This dental anomaly may sometimes be associated with some craniofacial deformities, e.g. Down syndrome, Klinefelter syndrome, amelogenesis imperfecta and Poly-X syndrome, etc.
  • Patients with hypodontia may have taurodontism in about 30% cases.
  • Anthropologic studies indicate that taurodontism was relatively common among Neanderthal men.
 
TREATMENT
No treatment is required for taurodontism; however this anomaly can pose some difficulty during root canal treatments.
 
DENS-IN-DENTE (DENS-INVAGINATUS)
 
DEFINITION
Dens-in-dente refers to a folding or invagination on the surface of the tooth towards the pulp; which begins before the calcification of the tooth and eventually after calcification the defect produces a typical appearance of a “tooth within a tooth”.
  • The defect in generally localized to a single tooth and interestingly maxillary lateral incisors are more often affected than any other tooth in the dental arch.
  • Bilateral involvement (of the same tooth on either side of jaw) is often seen and sometimes the defect can involve multiple teeth including the supernumeraries.
 
TYPES
Dens-in-dente is often broadly divided into two type—scoronal type and radicular type.
Coronal type: Coronal type of dens in dente occurs when the invagination or folding occurs on the crown portion of the tooth. The coronal type is further divided into three subtypes, which are as follows:
Type I—The invagination within the crown of the tooth.
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Type II—The invagination extends below the cemento enamel junction (CEJ) of tooth but it may or may not communicate with the pulp.
Type III—The invagination extends through the root and perforates in the apical or lateral radicular area.
Radicular type: In case of dens-in-dente if the invagination occurs in the root portion of the tooth it is called the radicular type and the condition presumably occurs due to folding of the Hertwig's sheath during the development of root.
 
CLINICAL FORMS OF DENS-IN-DENTE
Depending upon the extent or depth of the invagination towards the pulp, the dens-in-dente presents several clinical forms and these are mostly determined by radiographs.
Mild form: This form of dens-in-dente is characterized by the presence of a deeply invaginated or accentuated lingual pit area. Such external pits can be clinically inconspicuous but are clearly visible with the periapical radiographs.
Intermediate form: Intermediate form of dens in dente radiographically reveals a small, pear shaped invagination of the enamel and dentine into the pulp chamber, this produces a typical appearance of “tooth with in a tooth”.
Extreme form: In this form of dens-in-dente the invagination extends beyond the pulp chamber in the root of the affected tooth. This condition is sometimes known as “dilated odontomes”.
 
CLINICAL SIGNIFICANCE OF DENS-IN-DENTE
Since the base of the pit or the deep invagination in dens-in-dente is composed of a thin and often defective layer of enamel and dentine, this makes the tooth extremely vulnerable to caries soon after the tooth erupts into the oral cavity.
As a result most of the teeth with dens in dente frequently develop pulpitis, pulp necrosis, periapical cysts or periapical abscesses, etc.
 
TREATMENT
Early detection of the condition and restoration of the defect is the best treatment. In case of pulp involvement with or without apical pathology, endodontic treatment should be attempted. However in more severe form of the defect, extraction of the affected tooth should be done.
 
DENS-EVAGINATUS
 
DEFINITION
Dens-evaginatus is a rare developmental anomaly of tooth, in which a focal area of the crown projects outwards and gives rise to a “globe shaped” or “nipple shaped” protuberance on the occlusal surface. The projected portion often appears as an extra cusp or tubercle.
 
PATHOGENESIS
Dens-evaginatus probably develops as a result of excessive localized elongation and proliferation of the inner enamel epithelium as well as the odontogenic mesenchyme into the dental organ. The condition usually occurs during the early stage of tooth development.
 
CLINICAL FEATURES
  • Dens-evaginatus primarily affects the premolars and the affected tooth exhibits a globe shaped extra cusp or bump on the occlusal surface, which is often centrally located between the buccal and lingual cusps.
  • The condition can also affect the molars, canines or even the incisors. In such cases, the defect may occur either unilaterally or bilaterally.
  • Dens-evaginatus is commonly seen among Chinese, Japanese, Filipino, American-Indians and occasionally Caucasians.
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  • Clinically, this defect may sometimes interfere with tooth eruption and in such cases there may be incomplete eruption of tooth or displacement of tooth with occlusal disharmony.
  • Since the extra cusp contains a vital pulp-horn, its attrition, fracture or deliberate cutting may result in pulp exposure with pain, pulpitis and the other associated symptoms.
  • Similar complications may also arise when reduction of the extra cusp is attempted intentionally by the dentist.
 
TREATMENT
The condition usually does not require any treatment as long as it is asymtomatic. In case of occusal disharmony, minor reduction should be attempted. However, in case of exposure or fracture of the extra cup, endodontic treatment of the tooth should be done.
 
TALON CUSP
 
DEFINITION
Talon cusp is an anomalous projection from the lingual aspect of the maxillary and mandibular permanent incisors. A “talon” is the claw of a bird of prey and the name talon cusp has evolved since this anomalous structure often resembles an “eagle's talon”.
 
CLINICAL FEATURES
  • This abnormal cusp arises from the cingulum area of incisor teeth, which extends up to the incisal edge as a prominent T-shaped projection.
  • It is usually an asymptomatic condition however; in some cases it may cause problems like poor esthetics, increased susceptibility to trauma and caries and occlusal disharmony, etc.
  • The projected structure in talon cusp usually consists of normal appearing enamel and dentin; moreover in few cases there can be presence of vital pulp tissue as well.
  • Wearing or deliberate grinding of talon cusp may lead to pulp exposure and pain.
  • Occasionally lingual pits develop on either side of the talon cusp.
  • This anomaly is rare among general population; however it is often seen in patients suffering from Rubinstein-Taybi syndrome.
 
TREATMENT
  • Whenever the lingual pits are present restorative treatments should be done to prevent caries.
  • When talon cusp interferes with normal occlusion, preventive care should be taken by performing endodontic and restorative treatment.
 
ENAMEL PEARL
Enamel pearls are white, dome shaped calcified projections of enamel, usually located at the furcation areas of the molar teeth.
Maxillary molars are more frequently affected than any other teeth.
Enamel pearls are radiographically seen as 1 to 3 mm round radiopaque areas at the furcation region of tooth.
Histologically, these are composed of normal appearing enamel, sometimes with a central core of dentin.
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It is believed that the epithelial component of root sheath of Hertwig may sometimes retain its ameloblastic potential and therefore may synthesize enamel in some focal areas in place of cementum. This gives rise to the formation of enamel pearl.
 
DISTURBANCE IN THE STRUCTURE OF TEETH
 
DISTURBANCE IN THE STRUCTURE OF ENAMEL
Enamel is normally formed by the specialized odontogenic epithelial cells called ameloblasts and the entire process of formation of enamel takes place in three distinct stages, which are as follows:
Stage I:
Enamel matrix formation
(Secretory stage)
Stage II:
Initial mineralization
Stage III:
Enamel maturation
Enamel matrix formation: In the first stage or secretory stage the ameloblast cells cause synthesis and secretion of special proteins namely the amelogenins and enamelins. These two proteins constitute the basic structural elements of the enamel matrix.
Initial mineralization: Initial mineralization starts immediately after the secretion of enamel matrix proteins and during this the enamel microcrystals start to abut the plasma membrane of the ameloblast cells.
Maturation: The stage of maturation is characterized by simultaneous dual activity of withdrawal of protein and water from enamel with concomitant huge increase in its mineral content. All these three stages are completed before the eruption of the tooth in the oral cavity.
During the process of enamel formation, the ameloblast cells are susceptible to various external factors, which can damage the ameloblast cells and thus disturb the process of amelogenesis. The effect of disturbed amelogenesis is reflected on the surface enamel after the tooth erupts in the oral cavity.
Defect in the enamel due to disturbance during its formative process can be either qualitative or it can be quantitative.
  • Quantitatively defective enamel having normal thickness is known as enamel hypoplasia.
  • Qualitatively defective enamel having normal thickness is called enamel hypocalcification.
The type of developmental defect in enamel depends upon which factor was responsible for the defective amelogenesis and moreover the disturbance occurred during which stage of enamel synthesis.
Therefore depending upon the stages of formation of enamel; the defects arising in it under the influence of the external factors are as follows:
 
ACQUIRED DISTURBANCES OF ENAMEL
 
FOCAL ENAMEL HYPOPLASIA
When local infection or trauma causes damage to the ameloblast cells during odontogenesis, it may result in defects in enamel formation in isolated permanent tooth and this phenomenon is often known as focal enamel hypoplasia.
  • This is probably the most common form of enamel hypoplasia among all the varieties.
  • It occurs in permanent tooth due to periapical spread of infection from a carious deciduous tooth or from trauma to the deciduous tooth.
  • In such cases the trauma or the infection in the existing deciduous tooth may cause damage to the ameloblast cells, which are supposed to form the enamel of the underlying permanent successor.
  • The tooth affected in this process is commonly known as the “Turner's tooth”.
  • Depending on the severity of the injury, the crown of the Turner's tooth may only have an area of enamel hypoplasia that is relatively smooth with some pitting on the surface.
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  • However, in very severe cases, the crown of the Turner's tooth is grossly deformed and exhibits severe pitting with a yellowish or brownish discoloration of the surface.
 
IDIOPATHIC ENAMEL OPACITIES
This condition is characterized by white opaque spots on the smooth surface enamel, which occur due to some unknown cause.
  • Some of these spots may eventually turn brown after the tooth is erupted in the mouth.
  • Enamel opacities may affect deciduous as well as permanent dentition and maxillary central incisor is the most frequently involved tooth.
  • Histologically these opaque spots represent the area of hypomineralization.
 
GENERALIZED ENAMEL HYPOPLASIA
A short-term systemic or environmental disturbance in the functioning of ameloblasts at a specific period of time during odontogenesis often manifests clinically as a horizontal line of small pits or grooves on the enamel surface.
This line on the tooth surface indicates the zone of enamel hypoplasia and it corresponds to the time of development and the duration of the insult.
If the duration of the systemic or environmental insult is brief, the line of hypoplasia on the enamel surface will be narrow, whereas a prolonged insult may produce a wider zone of hypoplasia and also affect more number of teeth as well.
It has been observed from different clinical studies that generalized enamel hypolasia due to systemic or environmental disturbances usually involves those teeth, which develop in children during their first year of life. That is why the teeth like permanent incisors, cuspids and the first molars are often affected by generalized enamel hypoplasia.
Whereas the teeth like premolars, second molars and third molars are seldom affected by this defect since formation of the teeth begins usually 3 years after birth or even later.
 
EFFECT OF INDIVIDUAL SYSTEMIC CONDITIONS ON ENAMEL HYPOPLASIA
 
NUTRITIONAL DEFICIENCY
Since ameloblasts are amongst the most sensitive cells in the body in terms of metabolic requirements and any serious nutritional deficiency occurring during odontogenesis may result in generalized enamel hypoplasia of teeth.
  • Deficiency of Vitamin A, C, and D often causes injury to the ameloblast cells and results in enamel hypoplasia.
  • Hypoplasia of enamel due to nutritional deficiency commonly affects the central and lateral incisors, the cuspids and the first molars.
  • The teeth exhibit variable degrees of pitting on the enamel surface.
 
CONGENITAL SYPHILIS
Enamel hypoplasia resulting from congenital syphilis is a well known phenomenon.
  • The disease is contracted by the child in utero from a mother, who had active infection with Treponema pallidum.
  • In syphilis, the infection is diffuse in nature and it can involve virtually any organ of the body. However, certain body tissues like the bone, nerves and the teeth are more susceptible to this infection as compared to other tissues of the body.
  • The disease produces characteristic hypoplastic change in the enamel of permanent incisors and first molars due to infection to the developing tooth germ by Treponemal spirochetes.
  • The organism causes inflammation of the tooth germ during the morphodifferentiation stage resulting in hyperplasia in the epithelium of the enamel organ.
  • Because of the inflammation of the tooth germ and subsequent hyperplastic change in the enamel organ, enamel hypoplasia results often in association with some specific morphologic changes in the affected tooth.
  • In congenital syphilis, the affected permanent incisors exhibit tapering of the mesial and 50distal surfaces towards the incisal edge rather than toward the cervical margin and this gives a typical “screwdriver” appearance of these teeth.
  • Moreover, these teeth also have a central notch at their incisal edge and hence are called “Hutchinson's incisors”. These changes are more pronounced in maxillary central incisors.
  • The lateral incisors in congenital syphilis are usually “peg-shaped” and are called “peg-laterals”.
  • Congenital syphilis also produces some classic changes is molar teeth (usually the first molars), which are characterized by a crumpled and discolored occlusal surface and occlusal two third area of the crown.
  • The affected teeth are often covered by a globular mass of enamel and such teeth are popularly known as “Moon molars” or “Mulberry molars”.
  • It is important to note that not all the patients suffering from congenital syphilis will develop the hypoplastic enamel defects in their teeth as mentioned above.
  • Moreover, few people with no history of congenital syphilis may exhibit similar dental changes.
 
HYPOCALCEMIA
Enamel hypoplasia may result from hypocalcemia secondary to Vitamin-D deficiency and the defect is usually pitting type.
 
EXANTHEMATOUS DISEASE
Exanthematous diseases are a group of diseases caused by a number of viruses but these have a prominent common feature of skin rash, e.g. smallpox, chickenpox, cowpox, measles, rubella.
  • Severe form of these diseases in childhood often cause generalized enamel hypoplasia and it probably happens due to prolonged high fever associated with the infection, which may result in injury to the ameloblast cells.
  • In such cases the enamel hypoplasia will usually occur in those portions of the teeth, which are undergoing development at the time of infection.
  • Similar type of enamel hypoplasia can also occur in rickets and in congenital hypoparathyroidism.
 
BIRTH INJURIES AND LOW BIRTH WEIGHT
  • Enamel hypoplasia is a common developmental anomaly in case of birth injuries and it might result from a transient cessation of ameloblastic activity at the time of injury during labor.
  • Children of low birth weight often exhibit enamel hypoplasia and it probably results from oxygen deprivation and mineral depletion to the ameloblast cells during perinatal management.
  • Both deciduous as well as the permanent teeth develop hypoplastic enamel in these conditions.
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FLUORIDES AND MOTTLING
If fluoride levels in the drinking water exceeds 1 PPM (Parts per Million) it can cause mottling of enamel. Mottling is a type of enamel hypoplasia, which occurs as a result of damage to the ameloblast cells due to fluoride toxicity when the ion is absorbed in the body at a very high concentration. Besides causing damage to the enamel forming cells the excess fluorides also cause disturbance in the calcification process of enamel, and mottling actually results from this dual effect of fluoride toxicity.
 
CLINICAL FEATURES OF MOTTLING OF ENAMEL
  • Excessive amount of fluoride in drinking water causes sclerosis of the skeleton, which is characterized by calcification of the muscles and ligaments (especially intervertebral muscles and ligaments) with stiffening of the body and pain. The bone changes include increased thickening and mineralization similar to that of Paget's disease of bone.
  • Mottling is a generalized disturbance affecting all those teeth exposed to excess fluoride during odontogenesis or development of tooth (Fig. 1.26).
  • The condition does not affect adults.
  • Mostly the permanent dentition is affected and the involvement of deciduous teeth is rare.
  • The mottled teeth often have chalky or typical “paper white” opaque enamel with areas of flecking or pitting.
  • The damage can be extensive in some teeth, which exhibit fracturing of enamel with an associated brown or black pigmentation.
  • Mottled teeth are less susceptible to caries.
zoom view
Fig. 1.26: Fluorosis
 
HEREDITARY DISTURBANCE OF ENAMEL FORMATION
 
AMELOGENESIS IMPERFECTA
 
DEFINITION
Amelogenesis imperfecta is a heterogenous group of hereditary disorders of enamel formation, affecting both deciduous and the permanent dentition.
The disease involves only the ectodermal component of the tooth (i.e. enamel) while the mesodermal structures of tooth, (e.g. dentin, cementum and pulp), etc. always remain normal.
 
TYPES
Normally, the process of enamel formation progresses through three stages:
  1. Stage of enamel matrix formation.
  2. Stage of early mineralization.
  3. Stage of enamel maturation.
Amelogenesis imperfecta may set in during any stage of enamel formation. Four basic types of the disease have been identified, which corresponds with three developmental stages of enamel.
Type I
Hypoplastic type of amelogenesis imperfecta
Type II
Hypomaturation type of amelogenesis imperfecta
Type III
Hypocalcification type of amelogenesis imperfecta
Type IV
Hypomaturation Hypoplastic type with Taurodontism
 
Hypoplastic Type
The enamel thickness is usually far below normal in hypoplastic type of amelogenesis imperfecta since the disease affects the stage of matrix formation. The teeth exhibit either complete absence of enamel from the crown surface or there may be a very thin layer of enamel on some focal areas of crown.
 
Hypomaturation Type
This type occurs due to interruption in the process of maturation of enamel. Here the enamel is of normal thickness but it does not have the normal hardness and translucency (snow-capped tooth). 52The enamel can be pierced with an explorer tip with firm pressure.
 
Hypocalcification Type
Hypocalcification type of amelogenesis imperfecta represents the disturbance in the process of early mineralization of the enamel.
In this type of amelogenesis imperfecta, the enamel is of normal thickness but is soft and can be easily removed with a blunt instrument.
 
Hypomaturation-Hypoplastic Type with Taurodontism
This is a rare condition where taurodontism is reported in association with amelogenesis imperfecta.
 
CLINICAL FEATURES OF AMELOGENESIS IMPERFECTA (FIGS 1.27 AND 1.28)
  • Amelogenesis imperfecta affects both deciduous as well as the permanent dentition.
  • Sex predilection varies according to the mode of inheritance.
  • The color of the teeth is mostly chalky white but sometimes it can be yellow or even dark brown.
  • Besides the discoloration, these teeth are sensitive and are prone to disintegration.
  • The contact points in the proximal surfaces are mostly open either due to lack of formation or early loss of enamel.
    zoom view
    Fig. 1.27: Amelogenesis imperfecta-I
    zoom view
    Fig. 1.28: Amelogenesis imperfecta-II
  • The occlusal surfaces and the incisal edges of the teeth are often severely abraded.
  • Sometimes, the tooth may be completely devoid of enamel and the patient which results in severe abrasion of the dentin.
  • In some patients, the enamel may have a cheesy consistency which is easily removable from the tooth surface with dental explorers.
  • Amelogenesis imperfecta can be associated with retained deciduous tooth and delayed eruption of permanent tooth.
  • Alteration in the eruption pattern of teeth in amelogenesis imperfecta may further result in the development of anterior-open bite.
  • On rare occasions, the enamel may look almost normal except the presence of few grooves and wrinkles on its surface.
  • Amelogenesis imperfecta does not increase the susceptibility of the teeth to dental caries.
  • In the mildest form of hypomaturation type, the enamel is of near normal hardness and the teeth exhibit some white opaque flecks at the incisal margins. These types of teeth are known as “Snow-capped teeth”.
  • Amelogenesis imperfecta may occur either as an isolated disease or it may develop as part of a syndrome which includes features like nephrocalcinosis and hypocalciurea, etc.
 
RADIOGRAPHIC FEATURES
In amelogenesis imperfecta, the thickness and radiodensity of enamel varies greatly. The tooth may be completely devoid of enamel and wherever the enamel is present, it is very thin and found mostly on the tip of the cusps and on the interproximal areas (Fig. 1.29).
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zoom view
Fig. 1.29: Radiographic of Amelogenesis imperfecta
  • In hypoplastic type, the radiodensity of the enamel is usually greater than the adjacent dentin.
  • The radiodensity of enamel in hypomaturation type is almost equal to that of the normal dentin.
 
HISTOPATHOLOGY
Histologically, the enamel in hypoplastic type of amelogenesis imperfecta exhibits lack of differentiation of the ameloblast cells with little or no matrix formation (Fig. 1.30).
The enamel in hypocalcification type shows defective matrix structure and abnormal or subnormal mineral deposition.
The hypomaturation type reveals alteration in the enamel rod and rod-sheath structures.
zoom view
Fig. 1.30: Photomicrograph of amelogenesis imperfecta
 
TREATMENT
There is no definitive treatment for amelogenesis imperfecta, composite veneering can be done to improve overall aesthetics of teeth.
 
SYNDROME ASSOCIATED ENAMEL DEFECTS
A large number of syndromes and pathological conditions have been identified, which are often associated with hereditary enamel defects. In the following section few such syndromes or conditions have been discussed.
Epidermolysis bullosa: It is a bullous disease of the skin and mucous membrane. Dental defects associated with this condition include—enamel hypoplasia with random pitting.
Morquio's syndrome (Type-IV-Mucopolysaccharoidoses): Dental defects which occur in association with this syndrome include:
  • Enamel hypoplasia with pointed peak-like cusp tips.
  • Grey colored teeth with vertically oriented pits on the surface.
Sanfilippo's syndrome (Mucopolysaccharoidoses type-III): This syndrome presents features like-loss of enamel from the dentinal surfaces, defective formation of dentin and obliteration of pulp chambers.
Oculodento-osseous dysplasia: Dental defects in this syndrome include the following:
  • Thick mandibular bone.
  • Multifocal enamel hypoplasia of the tooth surface with pitting.
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  • Moth-eaten radiographic appearance of the teeth.
Amelo-onycho-hypohidrotic syndrome: This syndrome often shows severe hypoplastic-hypocalcified enamel.
Trichodentoosseous syndrome: Hypoplastic-hypocalcified enamel with pitting of the surface.
Rieger syndrome: Enamel hypoplasia with abnormally shaped teeth.
 
DISTURBANCES IN STRUCTURE OF DENTIN
Dentin is the first formed dental hard tissue and it is produced by the specialized odontogenic mesenchymal cells called the odontoblasts. These dentin forming cells or odontoblasts are derived from the mesenchymal cells of the dental papilla under the influence of the internal enamel epithelium. In the initial stage of dentin formation a collagenous matrix is formed, which is embedded in a ground substance rich in glycosaminoglycans (gag). When sufficient thickness the dentin matrix is laid down the odontoblast cells migrate through it centripetally and their processes remain in the matrix, which begin to mineralize later. Mineralization of dentin is initiated by the formation of small crystallines, which subsequently grow and fuse together to form discrete calcific globules called calcospherites.
Most of the factors causing interference in the process of dentinogenesis are genetic in nature. However there are some environmental factors as well, which can also cause disturbance in the normal dentine formation.
 
DENTINOGENESIS IMPERFECTA (HEREDITARY OPALESCENT-DENTIN)
 
DEFINITION
Dentinogenesis imperfecta is an inherited disorder of dentin formation, characterized by excessive formation of defective dentin, which results in obliteration of pulp chambers and root canals of tooth. The condition affects both deciduous as well as the permanent dentition and it usually exhibits an autosomal dominant mode of transmission.
 
TYPES
The disorder has been classified into three types:
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  1. Type-I
  2. Type-II
  3. Type III
 
Type-I: Dentinogenesis imperfecta associated with Osteogenesis imperfecta (OI)
  • This type is usually inherited as an autosomal dominant trait.
  • It involves the deciduous teeth more often than the permanent teeth.
  • Teeth will usually have an opalescent color (as seen in type II as well).
  • Patients will exhibit features of osteogenesis imperfecta (since both conditions occur together), which include bluish selera of the eyes and several bony defects.
  • It is important to note that not all cases of osteogenesis imperfecta will be associated with dentinogenesis imperfecta.
  • Moreover, there is no correlation between dentinogenesis imperfecta and the severity of the osseous defects present in osteogenesis imperfecta.
 
Type-II: Dentinogenesis Imperfecta not Associated with Osteogenesis Imperfecta
  • This type of dentinogenesis imperfecta is often known as “hereditary opalescent dentin”.
  • It is the most common type among all the three forms of the disease, having incidence rate about 1 in 8000 people.
  • The condition is inherited as an autosomal dominant trait.
  • Involves deciduous and permanent teeth with equal frequency.
 
Type-III: Dentinogenesis Imperfecta Type III or the “Brandywine Type”
  • Type III dentinogenesis imperfecta is a rare condition and is inherited as an autosomal dominant trait.
  • It is commonly seen in a racial isolate area in the state of Maryland.
  • It affects both dentitions and the disease is characterized by too little dentin formation in the tooth with presence of abnormally large pulp chambers.
  • Clinically the disease is same as type I and type-II variants, however it often exhibits multiple pulp exposures and periapical lesions in deciduous teeth.
  • Presence of little or no dentin in the tooth with large pulp chamber; results in a classic “shell tooth” appearance of the affected tooth.
 
CLINICAL FEATURES OF DENTINOGENESIS IMPERFECTA
  • In all three types of dentinogenesis imperfecta both deciduous and permanent dentitions are affected with variable clinical presentations.
  • The condition affects males and females with almost equal frequency.
  • On eruption, the teeth exhibit a normal contour but they have an opalescent “amber-like” appearance.
  • Few days after eruption, the teeth may achieve an almost normal color, following which they become translucent.
  • Finally the teeth become either gray or yellowish-brown in color with a bluish reflection from the enamel.
  • The teeth in dentinogenesis imperfecta often have “tulip” shape, which is characterized by a broad crown and a narrow constricted cervical area.
  • The overlying enamel is structurally normal in most cases, however this enamel is lost rapidly from the dentin surface soon after the teeth erupt in the oral cavity.
  • Enamel is lost early due to poor bonding between the enamel and dentin because of abnormal dentinoenamel junction. Early loss of enamel results in severe attrition of dentin (Fig. 1.31)
    zoom view
    Fig. 1.31: Dentinogenesis imperfecta showing generalized attrition of teeth
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  • In some cases of dentinogenesis imperfecta, the affected teeth may also exhibit hypomineralized areas on the surface enamel.
  • Teeth are not particularly sensitive even when most of the surface enamel is lost, it happens since the dentinal tubules are haphazardly arranged and most of them are devoid of the odontoblastic processes.
  • Although the dentin is soft and easily penetrable in dentinogenesis imperfecta, these teeth are not caries prone. The possible reason could be the structural change in the dentin itself, which provides little scope for the entry of the cariogenic microorganisms into the tooth since most of the dentinal tubules are obliterated in this disease (Fig. 1.32).
  • Type III cases of dentinogenesis imperfecta are often associated with multiple pulp exposures (mostly due to attrition) and periapical pathology.
 
RADIOGRAPHIC FEATURES
Radiographically dentinogenesis imperfecta reveals the following features (Fig. 1.33):
  • The type I and type II diseases are radiographically similar and they often exhibit “bulb shaped” or “bell shaped” crowns of the teeth with abnormally constricted cervical areas.
  • The roots of the teeth are thin and spiked.
  • Depending on the age of the patient, the teeth exhibit varying degrees of obliteration of the coronal as well as the radicular pulp chamber (Fig. 1.34).
  • The cementum, periodontal ligament and the alveolar bone radiographically appear normal.
    zoom view
    Fig. 1.32: Dentinogenesis imperfecta
    zoom view
    Fig. 1.33: Radiograph of dentinogenesis imperfecta X-ray
    zoom view
    Fig. 1.34: Dentinogenesis imperfecta showing obliteration of the pulp chambers of teeth
  • The type III dentinogenesis imperfecta exhibit extremely large pulp chambers surrounded by a thin shell of dentin and enamel.
  • Because of their typical appearance, the affected teeth in type III dentinogenesis imperfecta are often called “shell” teeth.
  • These teeth frequently exhibit multiple pulp exposure and associated periapical pathology.
 
HISTOPATHOLOGY
  • Histologically, the enamel appears normal in dentinogenesis imperfecta.
  • The mantle dentin (a narrow zone of dentin immediately beneath the enamel) is also nearly normal.
  • The major parts of the remaining dentin are severely dysplastic and exhibit vast areas of amorphous matrix with globular or intergobular foci of mineralization.
  • The dentinal tubules are far less in number per square unit area of dentin as compared to the normal dentin.
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  • These tubules are often distorted, irregular in shape, widely spaced and are often larger in size.
  • In many cases the odontoblastic processes are absent in the dentinal tubules, instead there can be presence of some degenerating cellular debris inside these tubules.
  • There may be large areas of atubular dentin present along with areas of noncalcified matrix.
  • Degenerating odontoblasts are often trapped inside the dentin matrix.
  • The pulp chamber and root canals are often obliterated by abnormal secondary dentin deposition.
  • The dentinoenamel junction appears smooth or flattened instead of being scalloped (Fig. 1.35). This abnormal configuration is mostly responsible for the early loss of enamel from the tooth surface in dentinogenesis imperfecta.
 
BIOCHEMICAL PROPERTY OF DENTIN
  • Biochemical analysis of the dentin in dentinogenesis imperfecta reveals increased water content and decreased mineral content.
    zoom view
    Fig. 1.35: Photomicrograph of dentinogenesis imperfecta showing loss of scalloping of the DEJ
  • The microhardness of the dentin is low as compared to the normal dentin.
 
TREATMENT
The treatment in dentinogenesis imperfecta is mostly aimed at preventing excessive tooth attrition and improving esthetics of the patients.
  • Metal and ceramic crowns are given.
  • These teeth are not suitable candidates for playing the role of abutments for any bridge work since the roots are small and they also tend to fracture under frictional stress.
  • In case of severe generalized attrition, complete denture prosthesis may be necessary.
 
DENTINAL ABNORMALITY DUE TO SYSTEMIC OR ENVIRONMENTAL DISTURBANCES
The environmental or systemic conditions, which can affect dentinogenesis are as follows:
  • Vitamin-D dependent rickets.
  • Vitamin-D resistant rickets.
  • Cytotoxic drugs.
  • Juvenile hypoparathyroidism.
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  • Hypophosphatasia.
  • Dentin dysplasia type II (thistle tube pulp).
 
VITAMIN-D DEPENDENT RICKETS
 
Dentinal Changes
Dentinal changes in this disease include the following:
  • The width or thickness of the predentin is increased.
  • Improper and incomplete calcification of the regular dentin.
  • Thick band like areas of interglobular dentin can be seen histologically, which correspond to the periods of active phase of the disease.
 
VITAMIN-D RESISTANT RICKETS (HYPOPHOSPHATEMIA)
 
Dentinal Changes
  • Increased amount of interglobular dentin formation.
  • These teeth exhibit large pulp chambers and long pulp horns. The later may even extend to the dentino enamel junction as narrow clefts.
  • The overlying enamel is defective and shows numerous cracks, which can serve as the direct pathways for entry of microorganisms into the pulp.
  • Many such teeth with this defect often exhibit pulpitis and periapical lesions even in the absence of caries.
 
HYPOPHOSPHATASIA
 
Dentinal Changes
  • Increased formation of interglobular dentin.
  • Widening of the predentine.
 
Cytotoxic Agents
Presence of many prominent incremental lines in the dentin, which often correspond to the periods of the drug (cytotoxic) administration.
 
Juvenile Hypoparathyroidism
Dentinal changes include:
  • Presence of small sized teeth in the arch.
  • Hypoplastic enamel.
  • Multiple prominent incremental lines can be seen in the dentine.
  • Roots of the teeth are small.
  • Histologically radicular dentine reveals many structural abnormally and there can be areas of vascular inclusions in the dentine.
 
DENTIN DYSPLASIA
 
DEFINITION
Dentin dysplasia is an autosomal dominant inherited disorder characterized by defective dentine formation and abnormal pulpal morphology, however the enamel in such teeth is absolutely normal. The condition is also known as “rootless teeth”.
 
TYPES
The condition is classified into two types:
  1. Type I or radicular dentin dysplasia.
  2. Type II or coronal dentin dysplasia.
 
Dentin Dysplasia Type-I (radicular)
Dentin dysplasia type-I represents a peculiar disturbance in the development of radicular dentin.
 
Clinical Features
  • There is no sex predilection.
  • Although, both types of dentin dysplasias are rare entities, however type-I dentin dysplasia is far more common than type-II.
  • The anomaly affects both deciduous as well as permanent dentitions.
  • Although the roots of the teeth are defective, the crown portions are normal both structurally and morphologically.
  • The color of the teeth is usually normal but in some cases the crowns of the teeth reveal a slight bluish or brownish translucency at the cervical region.
  • Unlike dentinogenesis imperfecta, the enamel does not chip off from the crown surface.
  • The teeth usually erupt at the normal time; although in some cases there can be delayed eruption.
  • Because of the presence of functionally unstable short roots, the affected teeth often exhibit severe mobility and they may even exfoliate prematurely due to minor trauma.
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  • Dentin dysplasia Type-I can occur in association with diffuse generalized osteosclerosis.
 
Radiographic Features
  • The roots of the teeth are characteristically malformed, short, blunt or conical.
  • Although presence of rudimentary roots is common, in many cases the teeth may be completely devoid of roots.
  • The deciduous teeth often exhibit total obliteration of the pulp chambers and root canals.
  • The permanent teeth also present pulp obliterations but there may be presence of very thin crescent shaped remnants of the pulp.
  • Obliteration of the pulp chamber in the affected teeth may occur even before the teeth erupt in the oral cavity.
  • The mandibular molars often exhibit characteristic “W” shaped roots.
  • Periapical radiolucencies of unknown etiology (e.g. periapical cyst, abscess or granuloma, etc.) may be found in many normal appearing teeth.
 
Histopathology
  • The enamel and mantle dentins are normal.
  • The remaining coronal and radicular dentin appear as a fused nodular mass comprising of tubular dentin, osteodentin and amorphous dentin mass.
  • Histologic appearance of such defective mass of dentinal tissue often resembles, what is called “a series of sand dunes” or “lava flowing around boulders”.
  • Remnants of pulp tissue may occasionally be seen between the normal and the abnormal dentinal tissue.
  • The normal and the abnormal dentin are well demarcated and the later reveals an abnormal distribution and orientation of the dentinal tubules with a typical whorled appearance.
 
Pathogenesis
Dentin dysplasia type I develops probably due to a defect in the epithelial root sheath of Hertwig, which fragments and becomes incorporated into the dental papilla, where it induces formation of dysplastic dentin.
 
Treatment
No specific treatment is available. These teeth also do not serve as good abutments since their roots are very short.
 
Dentin Dysplasia Type-II (Coronal)
 
Definition
It is an inherited autosomal dominant disorder of dentine, which mostly affects the coronal dentine.
 
Clinical Features
  • Both deciduous and permanent teeth are affected in this disorder.
  • The permanent teeth are of normal color, whereas the deciduous teeth exhibit an “ambergray” color with some translucent or opalescent appearance.
  • There is no sex predilection.
 
Radiographic Features
  • The deciduous teeth in dentin dysplasia type II reveals obliterated pulp chambers and root canals, thereby resembling dentinogenesis imperfecta.
  • Permanent teeth exhibit large pulp chambers with a typical “thistle tube” appearance.
  • Pulpal obliteration occurs only after tooth eruption.
  • The roots of the deciduous and the permanent teeth are usually of normal shape and length.
  • Unlike dentinogenesis imperfecta there is no cervical constriction of the teeth in dentin dysplasia type-II.
  • The pulp chambers in permanent teeth are abnormally large instead of being obliterated and have a typical flame shape.
  • The pulp chamber contains many pulp stones or denticles.
  • Root canals may be partially obliterated in the apical third region.
 
Histopathology
  • The deciduous teeth exhibit a dense amorphous mass of dentin, which contains only few haphazardly arranged dentinal tubules.
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  • The permanent teeth show normal dentinal structures but may have the presence of abnormal globular or interglobular dentin near the pulpal third area and in the roots.
  • The pulp chambers exhibit the presence of numerous pulp stones.
 
Treatment and Prognosis
No special treatment is required in case of dentin dysplasia type-II. Prognosis is good for the permanent teeth since their root length is essentially normal.
 
REGIONAL ODONTODYSPLASIA (GHOST TEETH)
 
DEFINITION
Regional odontodysplasia is an uncommon but unique nonhereditary developmental disturbance of teeth, characterized by defective formation of enamel and dentin, in addition to abnormal pulp and follicle calcifications.
 
ETIOLOGY
The etiology is not fully understood but it is suggested that the disease develops due to some local ischemic change in the tissue during odontogenesis. Some investigators suggest a viral etiology for this condition.
 
CLINICAL FEATURES
  • Both permanent and deciduous dentitions are affected in this disease although it is more common in permanent dentition.
  • There is no sex predilection.
  • The maxillary teeth are affected more often than the mandibular teeth.
  • The disease is called regional since it affects several contiguous teeth in a single quadrant of the jaw.
  • It frequently occurs unilaterally, often affecting certain parts of maxilla.
  • The central and lateral incisors and the cuspids in the maxillary arch are often affected.
  • The affected teeth show either delayed eruption or a complete failure of eruption.
  • These teeth are often deformed, have a soft leathery surface and are yellowish-brown in color.
 
RADIOGRAPHIC FEATURES
The teeth is regional odontodysplasia have often been described as “ghost teeth”, since there is marked decrease in the radio-density of these teeth as a result of defective mineralization.
  • The enamel and dentin are very thin and radiographic distinction between these two structures is impossible, this accounts for the subdued or “ghostly” appearance of the involved teeth.
  • Pulp chambers of the teeth are extremely large and open, and often they contain pulp stones.
 
HISTOPATHOLOGY
  • The enamel layer is attenuated and disrupted.
  • Dentin is very thin and globular, and exhibits irregular tubules and a wide predentine layer.
  • Large pulp chamber exhibits numerous pulpal calcifications.
  • The reduced enamel epithelium persists and the follicular connective tissue contains numerous clusters of tiny droplet calcifications.
 
TREATMENT
Extraction of the affected teeth and fabrication of a suitable prosthesis is usually recommended.
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DISTURBANCE IN STRUCTURE OF CEMENTUM
Cementum is the odontogenic mesenchymal tissue, which covers the root surface of teeth. There are two types of cemental tissues found:
The acellular or primary cementum: Which covers the coronal one third of the roots.
The cellular or secondary cementum: It covers the apical two thirds and furcation areas of the teeth. The cellular cementum often has a thicker layer and it continues to form throughout the life of the tooth.
There are two main types of defects seen in the cementum:
  • Hypercementosis
  • Hypocementosis.
 
HYPERCEMENTOSIS
 
DEFINITION
It represents an increased and abnormal thickness of the cementum, which results from abnormal cementogenesis.
 
ETIOLOGY
  • Periapical inflammation: Periapical inflammation in a tooth causes cemental resorption at it's centre position, however this also causes cemental opposition on the root a little further away. This may result in either a generalized increase in the thickness of cementum or a localized “knob-like” enlargement.
  • Mechanical stimulation: Although excessive mechanical forces applied to a tooth produce cemental resorption but forces below a certain threshold level may stimulate cemental apposition and subsequent hypercementosis.
  • Nonfunctional and unerupted teeth: These teeth sometimes show cemental resorption but excessive apposition of cementum is also possible.
  • Paget's disease of bone: Hypercementosis is a common feature of Paget's disease of bone. The cementum in this disease is very thick and it often has a mosaic pattern.
  • Root ankylosis and concrescence: Teeth in these conditions may be associated with hypercementosis.
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HYPOCEMENTOSIS
Hypocemtosis or acementosis is a rare developmental anomaly of tooth characterized by lack of cementum formation in the tooth.
 
CAUSE
  • Cleidocranial dysplasia
  • Hypophosphatasia.
Hypocementosis prevents the normal development of the periodontal attachment or even the normal dentin formation. Premature loss of few or all deciduous and permanent teeth may occur in this disease.
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