Risk factors:
(1) middle age or elderly adult
(2) female gender
(3) a history of previous TMJ surgery
(4) a history of trauma involving the jaw
(5) a history of infection involving the TMJ
(6) a metabolic disease affecting joints
(7) a jaw deformity
Clinical features:
(1) pain on moving the mandible, which may be unilateral or bilateral
(2) limited range of motion for the TMJ
(3) deviation of the jaw towards the affected side
(4) tenderness on palpation of the TMJ
(5) grating, grinding or crunching sounds during joint movement
Imaging studies may show:
(1) detached fragments of bone or cartilage (joint mice)
(2) narrowing of the joint space with degenerative changes
The diagnosis often requires exclusion of other disorders of the TMJ.