Plate fixation of extra-oral subcondylar ramus osteotomy for correction ofmandibular prognathism: clinical aspects and short term stability

Aim: The present study describes an extra-oral approach for subcondylar obl ique ramus osteotomy using stable fixation for setback of the mandible. The aim was to investigate the incidence of neurosensory disturbances of the m andibular nerve, evaluate facial scar appearance, and assess skeletal stabi lity following the procedure. Methods: Forty-two consecutive patients with mandibular prognathism were operated upon using the subcondylar oblique ram us osteotomy and plate fixation. The patients were followed up for 6 months following surgery. Intra-operative and postoperative complications, neuros ensory function, and facial scar characteristics were recorded. Lateral cep halograms were available immediately before operation, and immediately afte r operation and 6 months postoperatively. Skeletal stability was based on c ephalometric assessment. Results: Among the 19 patients operated earliest, neurosensory disturbances were recorded in five individuals at the 6 month follow-up. In the subsequent group of 23 patients, no disturbances were rep orted. All but two patients were not concerned about the facial scar 6 mont hs postoperatively. Mean anterior relapse at the 6 month follow-up was 0.5 mm, representing 9% of the surgical setback. Conclusion: Extra-oral subcond ylar oblique ramus osteotomy with plate fixation is a stable procedure with a low incidence of neurosensory disturbances if the osteotomy is placed we ll behind the mandibular foramen. Facial scar appearance was rarely a matte r of concern to the patients. (C) 2001 European Association for Cranio-Maxi llofacial Surgery.