Greater mandibular horizontal condylar angle is associated with temporomandibular joint osteoarthritis.

BACKGROUND: Research using magnetic resonance imaging analysis has shown that internal temporomandibular joint derangement is associated with significantly greater horizontal condylar angle. However, the association between osteoarthritic (OA) bony changes as shown on computed tomography and horizontal condylar angle has never been evaluated. OBJECTIVE: To investigate the relationship between mandibular condylar angle and OA degenerative changes. STUDY DESIGN: This is a retrospective study using cone beam computed tomography images and reports from 60 patients with unilateral OA degenerative changes and 43 control patients with no OA-affected joints. RESULTS: Condylar angles in the joints of control patients and the unaffected joints in OA patients were not significantly different. The mean horizontal condylar angle in the unilaterally OA-affected joints (29.5 degrees +/- 10.5 degrees ) was larger than in the contralateral unaffected joints (22.5 degrees +/- 7.7 degrees ) (P < .001). In the OA-affected joints, flattening and erosion of the articular eminence was associated with a greater condylar angle (P < .05). CONCLUSIONS: Moderate to severe degenerative temporomandibular joint change is associated with greater horizontal condylar angle.