We report a case of agenesis of the bilateral mandibular condyle. The patient was a 43-year-old male without any history of eventful delivery and trauma. His chin had been retruded since childhood. After extraction of the upper-right third molar in September 1998, he felt discomfort in his right cheek. He was referred to our hospital on March 23, 1999.
His height and weight were 170 cm and 60 kg, respectively. There was no evidence of Raynaud's phenomenon, and no abnormal finding on his skin and joints. No abnormalities were found on his eyes, eyelids, ears and hearing. The degree of mouth opening was 40 mm. The dental arch was parabolic with 10 mm of overjet and 2 mm of overbite, and the number of teeth was normal. Relatively good occlusion was observed in the molar region. Panoramic X-ray revealed the absence of mandibular condyle, short ramus and deep hollow on the mandibular plane in front of the mandibular angle. Lateral cephalogram demonstrated a small mandible and stricture of the airway. Though they were CT findings, the condylar head and articular disc on both sides were absent, and the base of the condylar process was positioned anteriorly to the glenoid process. Although the lateral pterigoid muscle ran to the inner surface of the mandibular ramus, there were no abnormal findings on zygoma, ear and mastication muscles. Laboratory data revealed no evidence of autoimmune disease such as rheumatism or scleroderma. This case was considered to be congenital absence of bilateral mandibular condyle, because the articular disc, which is thought to be developed from mesenchymal cells from which the condyle is also developed, could not be detected.