Synovial chondromatosis of the temporo-mandibular joint. Report of three cases and a review of the literature.

Synovial chondromatosis of the temporo-mandibular joint is a rare affection, characterized by the formation of cartilage particles in the synovial membrane. These particles can break through and enter the joint compartments. The diagnosis must be considered for patients who complain of slowly progressive swelling, pain, and crepitus in the region of the temporo-mandibular joint. When the changes are not visible on plain X-rays due to absence of ossification, important diagnostic information can be obtained by a technetium 99m (99m Tc) bone scan and a computerized tomography (CT) sialogram. The diagnosis can be established only by histopathologic examination of surgically removed particles or resected synovial membrane. Discussed are 25 cases of histopathologically verified chondromatosis of the temporo-mandibular joint reported in the literature, as well as 3 new cases seen and treated at the University Hospital Groningen since 1970. A good clinical result can be obtained by removal of all particles and synovectomy. Condylectomy is seldom required.