Clinical and radiologic findings of synovial chondromatosis affecting the temporomandibular joint

Objectives. Our aim was to study the clinical and radiologic findings of synovial chondromatosis (SC) affecting the temporomandibular joint (TMJ) and provide references for diagnosis and treatment. Study design. Twenty patients confirmed as SC histopathologically were included in the investigation. Nineteen cases were treated with arthrotomy and 1 case with arthroscopy. The clinical manifestations, radiographic findings, histopathologic features, surgical treatment, and differential diagnosis were combined to study this disease. The SC features of TMJ on magnetic resonance (MR) images were summarized on proton density-weighted (PD) and T2-weighted images. Results. Synovial chondromatosis of TMJ occurred more often in women and on the right. Symptoms included preauricular pain, swelling, limitation of mouth opening, crepitations, and deviation on opening. The detection rate of calcified loose bodies was 30% on conventional radiographs and 53.3% on computerized tomography. Multiple small ring-like or tubular signals could be seen on PD and T2-weighted MR images. SC mainly affected the superior joint space; it could involve the inferior space when a perforated or deformed disc was present. SC could extend into intracranial fossa, infratemporal fossa, and lateral pytergoid muscle. Conclusions. The characteristic ring-like signals could be found on MR images of the patients with SC of TMJ. This lesion should be differentially diagnosed with TMJ disorders and preauricular masses. Considering its recurrence and the different behavior of SC in different patients, various treatment strategies should be considered. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: 441-448)