In this chapter how to locate the canal orifice from the coronal/pulpal side is explained. How to locate the canal orifice in the upper and lower molars, premolars, deciduous teeth, anomalies of the pulp canals, etc. are all described in details supported by many figures to make the point very clear. At what age the calcification/completion of apical foramen is completed, which is so important for endodontic practice is given in a table-form both for deciduous and permanent teeth. A very special feature of individual tooth bio-data is covered under the headings of average length of tooth, numbers of roots, numbers of root canals, lateral canals if present, furcations (delta) of the root canals at the apex, distance at which apical foramen is located/situated from the apex, diameter of the root canal at 1-2-3-5 mm from apex is also given, and finally up to what size widening of the root canal is recommended, is given. Normally the readers are required to consult many different subject books like dental anatomy, physiology, pathology, periodontia, endodontics, etc. to collect these data, but here they are given under one heading. Figures of root canals in buccal, proximal, Incisal or occlusal views are also given with bio-data of each tooth, which helps to make endodontic practice very easy.