Temporomandibular joint is a ginglymus diarthrodial joint that permits movement of the lower jaw. This flexibility of motion is responsible for various functions of the craniofacial region. The association of TMJ disorders and various malocclusions is still an enigma to orthodontists and maxillofacial surgeons alike. Before studying the anomalous TM joint, one should understand the anatomy and physiology of a normal TMJ. The chapter outlines the anatomy, developmental embryology, histology, evolution and function of the joint.