MORPHOLOGIC STUDY OF THE MANDIBULAR FOSSA AND THE EMINENCE OF THE TEMPOROMANDIBULAR-JOINT IN RELATION TO THE FACIAL STRUCTURES

To clarify the relationship between the temporal component of the temp oromandibular joint and facial bone structure, we measured anthropolog ic craniometric points and the structure of the mandibular fossa, incl uding the eminence in 33 Japanese male dry skulls, with a three-dimens ional apparatus. The length from the articular tubercle to the medial glenoid tubercle is correlated with skeletal variables such as the len gth of the fossae, the width of the masseter origin, and the mandibula r length. Therefore it appears that the frontal dimension is related t o the facial development, which is attributable to bite force. Goniome trically, the angle between the line deepest point of the fossa-the mi dpoint of the eminence and the Frankfort horizontal plane (middle angl e)-was negatively correlated only with the ANB angle, suggesting that a steeper middle angle of the eminence is related to a retrusive maxil la or protrusive mandible.