[Synovial chondromatosis (chondrometaplasia). Contribution to the differential diagnosis of temporomandibular joint diseases]

[Joint loose bodies in the mandible. Diagnostic criteria and pathways for therapy planning]

Osteochondrosis dissecans (OD) and synovial chondromatosis (SC) are two rare causes for loose bodies in the temporomandibular joint. It is assumed that OD is a reaction of some type of joint trauma. Gene mutations similar to what is known in chondrosarcomas can be found in metaplastic SC. The reasons for mutations are still unknown. Both diseases have very similar symptoms. Patients suffer from preauricular swelling, facial or temporomandibular joint pain, and occasional joint locking. In addition, radiological imaging (MRI) is difficult in evaluating the differential diagnosis of presented intra- or periarticular pathology. To overcome diagnostic problems, we strongly support temporomandibular joint arthroscopy as a diagnostic and therapeutic tool. The decision whether or not total synovectomy is needed or if simple removal of fragments is adequate can be evaluated in vivo including the option of histopathological examination.

Synovial chondromatosis of the temporomandibular joint: clinical, diagnostic, and histomorphologic findings

Objective. The primary diagnosis of synovial chondromatosis of the temporomandibular joint is extremely rare. Often many months, or even years pass before the diagnosis is confirmed. Study Design. Eight patients with synovial chondromatosis were treated by arthrotomy. In addition to the definitive diagnosis, histologic classification according to the stages proposed by Milgram was undertaken and confirmed with the literature. Results. The predominant symptoms of synovial chondromatosis, including pain, swelling, restricted movement of the mandible, and crepitation, were evaluated. Nevertheless, more than 80% of the patients were previously primarily treated on the basis of other tentative diagnoses. Conclusion. Synovial chondromatosis of the temporomandibular joint should be included in the differential diagnosis of chronic swelling and pain in the preauricular region, and the patient should be sent for appropriate diagnostics and therapy at an early stage.