The position of the mandibular condyle at maximal mouth opening in normal subjects

Purpose : To investigate the position of the mandibular condyle at maximal mouth opening in individuals 19 to 30 years of age with no functional disorders of the masticatory system. Patients and Methods : Measurements were made in 153 subjects (99 men, 54 women), and 41 men and 44 women had transcranial radiographs taken of their right and left temporomandibular joints in the closed and maximal opening positions. Results : In all subjects the condyle moved forward beyond the summit of the articular eminence, and in more than half the subjects the condyle was located inferior to the eminence at maximal opening. Conclusion : The correlation between maximal opening and anterion shift of the condyle from the summit of the eminence was significant, but the correlation with vertical shift of the condyle was not significant. The correlation between the form of the glenoid fossa (length and depth) and anterior or vertical shift of the condyle from the summit of the eminence also was not significant.