Abstract
Osteoarthrosis associated with findings of avascular necrosis of the mandibular condyle on magnetic resonance imaging was clinically evaluated. The subjects consisted of 5 female unilateral cases, with an average age of 55.4 years who had a mean duration of illness of 15.2 months. The symptoms were a mean interincisal opening distance of 32.8mm with arthralgia in mild to moderate degree, and joint noise (crepitation) in all joints. MRI documented decreasing signal intensity of the condyle with 2 joints in high degree and 3 joints in moderate, as well as variable low signal density of the articular eminence, associated with concomitant anterior disk displacement. X-ray showed deformity of the condyle and eminence. The operative findings disclosed disk rupture and comparatively smooth cartilage with minimum remodeling of the condylar surface; however, avascular evidence was suggested when corticotomy was performed. Four joints underwent diskectomy, condylar shaving, auricular cartilage grafts and corticotomy of the condyle. Arthroscopic corticotomy was applied for 1 joint with mild symptoms. Postoperative symptoms improved to mean opening distance of 41. 4mm and the disappear of arthralgia in 4 joints. The surgical outcome was excellent in 3 joints and good in 2 joints. Follow-up MRI in 2 cases disclosed increasing signal intensity, which suggested recovery of condylar vascularity following corticotomy.
It is suggested that the low-signal intensity on MRI in osteoarthrosis might indicate avascular lesions of the condyle, secondary to degenerative change. Histologic investigations are required to evaluate avascular necrosis of the temporomandibular joints.
