ABSTRACTThe study of temporomandibular joint (TMJ) and its relationship to function of the stomathognathic system has been a topic of interest in dentistry for many years. This relationship has proved to be quite complex. The TMJ is certainly one of the most complex joints in the body. As knowledge of the anatomy and physiology of the TMJ increases, and instruments and techniques for measuring dynamic skull-fossamandibular factors are developed, many more general dentists are attempting to—and are expected to- diagnose and treat TMJ-oriented problems. Temporomandibular disorders (TMD) include clinical disorders involving the masticatory muscles, the TMJ and the adjacent structures. TMD was recognized as a main source for pains in the orofacial area, which are not caused from dental origin, and is defined by the American Academy of Orofascial Pain (AAOP) as a sub-group within the frame of musculoskeletal disorders. The main etiology for TMD has not been found yet.