Asymptomatic, radiologically detected chondrometaplasia in the temporomandibular joint

Asymptomatic loose bodies were detected in the temporomandibular joint of a 62-year-old woman during an examination before comprehensive dental care. The radiologic interpretation was synovial chondrometaplasia (synovial osteochondromatosis). A histologic diagnosis was not obtained, because surgery was unwarranted in view of the lack of symptoms and the benign differential diagnosis. Review of the literature revealed 62 reported cases of temporomandibular joint chondrometaplasia, all of which included one or more of the following: swelling, pain, joint noise, and limited mandibular movement. These reports have described this entity as a rare lesion, but the rate of reports has increased, perhaps because of greater practitioner awareness and increased sensitivity of diagnostic tests.