Inclination of the temporomandibular joint eminence and anterior disc displacement

The articular eminence angle of 179 temporomandibular joints (TMJ) with anterior disc displacement (ADD) in 179 patients was measured and compared with 200 left and 200 right joints of 400 young adults without TMJ dysfunction. A steeper inclination of the posterior slope of the articular eminence, with a mean difference compared to the control group of 14.5 degrees, was seen in joints with ADD. In the group of 179 joints with ADD of the TMJ, no difference was seen in the mean articular eminence angle between joints with an ADD with reduction, and an ADD without reduction, between conservatively or surgically treated joints, or between joints with different presumed causes of ADD.