A 34-year-old male patient presented with a gradual facial asymmetry and occasional discomfort in the right temporomandibular joint (TMJ). Initial evaluation, including panoramic radiography, suggested facial asymmetry secondary to condylar elongation. However, computerized tomography and magnetic resonance imaging demonstrated the existence of a condylar mass and multiple calcified lesions within the right TMJ. The patient did not recognize any occlusal changes, but it was suspected that the occlusion had changed based on the cast analysis. The patient underwent a condylectomy and mass excision, which confirmed the diagnosis of osteochondroma with concurrent synovial chondromatosis. Approximately three weeks of postoperative physical therapy were required to achieve stable occlusion. This case is notable for two reasons. First, the simultaneous occurrence of osteochondroma and synovial chondromatosis is extremely rare. Second, the gradual occlusal changes associated with TMJ lesions can go undetected, increasing the chance of misdiagnosis.

Both synovial cysts and synovial chondromatoses originate from synovial tissue, and only one case has been reported to occur simultaneously in a patient. Our patient presented with a swelling of the right preauricular area and pain on opening the mouth. Magnetic resonance images demonstrated two cystic structures in the superficial lobe of right parotid gland. Under the clinical impression of a cyst in the salivary gland, an enucleation was performed. However, the final diagnosis based on microscopic examination was a synovial cyst associated with the right temporomandibular joint and a synovial chondromatosis arising within the cystic wall. Awareness of this combined lesion will help make a diagnosis and establish a proper treatment plan.