Synovial chondromatosis of the temporomandibular joint: clinical, surgical and histological aspects.

Nine patients with histologically confirmed unilateral synovial chondromatosis of the temporomandibular joint were treated surgically with extirpation of loose bodies and partial synovectomy. In six of them the histological material was available for a systematic examination. The results of treatment were evaluated clinically and with MRI after a follow-up ranging between 1 and 17 years. Our findings suggest that synovial chondromatosis of the temporomandibular affects only the synovial lining of the upper compartment. The histological appearance is that of a benign chronic inflammation varying in severity and with metaplastic activity. The most specific clinical sign of synovial chondromatosis is swelling over the joint. Distension of the lateral capsule and fluid in the joint on the MRI are very suggestive of this diagnosis. Loose bodies also indicate synovial chondromatosis, but they are not always detected on the preoperative MRI. The surgical treatment should be conservative and include thorough removal of the loose bodies and partial synovectomy in areas with marked inflammation.