Relationship between sex, age, and the minimum thickness of the roof of the glenoid fossa in normal temporomandibular joints.

This autopsy study investigates the minimum thickness of the roof of the glenoid fossa of grossly normal temporomandibular joints (TMJ) and correlates this to gender and age. This study was based on 49 TMJ specimens collected from 26 male and 23 female cadavers whose mean age at death was 73.8 years (range=50-96). No information was available about TMJ symptoms before death. A digital micrometer was used to measure the minimum thickness of the glenoid fossae. Comparisons were made based on gender and age. The mean value for the minimum roof thickness of all joint specimens examined was 0.8 mm. Mean values for male and female specimens were 0.8 and 0.7 mm, respectively, which were not significantly different. In addition, no age-related differences were observed. The average thickness was 0.7 mm for individuals in their fifties, 0.8 mm for those in their sixties and seventies, 0.6 mm for those in their eighties, and 0.8 mm for individuals in their nineties. Although these data indicate that the minimum thickness of the glenoid fossa of the TMJ is not significantly correlated with sex or age in patients 50 years of age and older, they nonetheless provide additional information about normal TMJ anatomy, particularly with regard to our knowledge of joint remodeling and function in the disease and non-disease states. Thickness of the glenoid fossa has also been implicated as a factor in facial trauma involving superior displacement of the mandibular condyle into the middle cranial fossa. The thickness of the glenoid fossa is also of potential interest during surgeries involving the glenoid fossa, such as TMJ arthroplasty or joint reconstruction.