Bimaxillary Osteodistraction in Adult Facial Asymmetry

ABSTRACT

We treated 9 patients with hemifacial microsomia or facial asymmetry between April 1998 and November 1999. The age of patients ranged from 21 to 45 years(mean 24.6). Six were women, 3 were men. The follow up period was 6 to 24 months(mean 15.3 months). The operative procedure was based on the Ortiz Monasterio's simultaneous mandibuiar and maxillary distraction technique. Ortiz Monasterio only freed the pterygomaxillay junction of the affected side, leaving the nasal septum and pterygomaxillary junction of the unaffected side intact. They also used external corticotomy on mandible. We modified the original Ortiz Monasterio's method by using complete Le Fort I osteotomy with complete separation of both pterygomaxillary junction and mandibular osteotomy to avoid the resistance during the distraction. In one patient of scleroderma with severe atrophy of the mandible and soft tissue on the right face, a free scapular osteocutaneous flap was done. One month later, simultaneous distraction of the maxilla, the transferred scapula bone and the mandible was performed. Among the 9 patients, bidirectional distraction was done in one patient, and intraoral device was applied in 3 patients. After 5 days of latent period, distraction was performed at a rate of 1 mm per day. After 6 to 8 weeks of consolidation period, intermaxillary fixation and distraction device were removed. Preoperatively, the deviation of occlusal plane ranged from 8 to 13 (mean 10.5 ). The length of distraction ranged from 7 mm to 20 mm(mean 13 mm). In 2 patients, there were radiologic evidences of relapse 6 months after distraction, but no significant change of facial appearance was found. Seven patients have maintained stable preoperative occlusion of of teeth as previous conditions and preoperative lateral open bite was improved postoperatively in 2 patients. Postoperative occlusal plane ranged from 0 to 1.