Abstract: PURPOSE: Arthroscopy facilitated open surgery was carried out for the treatment of synovial chondromatosis of temporomandibular joint (TMJ), its indications and effects were discussed. METHODS: Patients with synovial chondromatosis of TMJ who were hospitalized from September 2010 to February 2015 were included in this study. Clinical and medical imaging examinations were conducted prior to surgery in order to confirm the diagnosis and range of the tumor. For those with tumors in their upper articular cavities and medial groove expansion of the joint capsule still in between medial crest of the condylar head and inferior temporal gap, shown by their coronal MRI reconstructions, arthroscopy was chosen to assist the open surgery procedure in resecting free substances and performing a thorough clean-up of TMJ capsule and synovium. Post-operative joint-jaw-occlusion relationship examinations and long-term imaging follow-ups were conducted to evaluate the clinical effect of this treatment. RESULTS: Free substances were found in the resected TMJ capsules of 36 patients by open surgery. Further examinations with arthroscopy indicated that more free substances were contained in the medial groove or the anterior and posterior recessus of 14 patients, which were all removed using a cup-shaped clamp. A finishing touch of a thorough clean-up of the joint capsule and synovium was applied with arthroscopy; pathologic examinations proved the diagnosis of synovial chondromatosis. After treatment, all patients experienced good recoveries of their TMJ functions and achieved stable occlusions and face shapes. MRI scans in an average of 33.3 months after surgery indicated no recurrence of the tumor. CONCLUSIONS: Arthroscopy can be a great facilitating tool in open surgery to detect the articular cavity from multiple perspectives. Utilization of this technique has benefits in a complete elimination of the diseased tissues with minimal osteotomy required and reductions of the wounded area and surgical time. Thus, arthroscopy can serve as a powerful complementary to the conventional surgical procedures.

Key words: Temporomandibular joint, Synovial chondromatosis, Arthroscopy, Open surgery