Synovial chondromatosis originally arising in the lower compartment of temporomandibular joint: a case report and literature review.

INTRODUCTION: More than 200 cases of synovial chondromatosis (SC) in the TMJ were reported. Most of SC described exclusively involved the upper compartment of the joint. SC originally arising in the lower compartment is rarely found.

MATERIAL AND METHODS: This article presents a 50-year-old man with a slow growing, pain, preauricular swelling in left side and the limitation of mouth-opening. Panoramic radiograph, CT scans and MR images were taken. An arthroscopic examination and a surgical intervention were performed.

RESULTS: Panoramic radiograph and CT scans didn't reveal the calcifying lesions in left TMJ region. Sagittal MR images and the arthroscopic examination demonstrated distinct nodules within an extremely expanded lower joint compartment and a normal position of the articular disc. All loose bodies and grossly abnormal synovium were removed. The diagnosis of SC was confirmed by histologic examination.

CONCLUSION: MRI and arthroscopy may be helpful diagnostically. Removal of all involved synovium, and loose cartilaginous bodies may be required for adequate treatment.