Bimaxillary osteodistraction for the treatment of facial asymmetry in adults

Nine patients with hemifacial microsomia or facial asymmetry were treated between April 1998 and November 1999. The ages of the patients ranged from 21 years to 45 years (mean: 24.6 years); six were female and three were male. The follow-up period ranged from 6 months to 24 months (mean: 15.3 months). The operative procedure was based on Ortiz Monasterioʹs simultaneous mandibular and maxillary distraction technique. This technique frees only the pterygo-maxillary junction of the affected side, thereby leaving the nasal septum and the pterygo-maxillary junction of the unaffected side intact. It also uses an external corticotomy on the mandible. In contrast, we modified Ortiz Monasterioʹs method by using a complete LeFort I osteotomy with both a complete separation of the pterygo-maxillary junction and a mandibular osteotomy to avoid any resistance during distraction. In one patient with scleroderma and severe atrophy of the mandible and soft tissue on the right side of the face, a free scapular osteocutaneous flap was used; 1 month later we performed simultaneous distraction of the maxilla and transfer of the scapula bone to the mandible. In one patient with hypoplasia of the zygoma, zygoma expansion was also performed simultaneously. Bidirectional distraction was performed in one patient and intraoral devices were applied in three patients. After a latent period of 5 days, distraction was performed at a rate of 1 mm per day. After a consolidation period of 6–8 weeks, the intermaxillary fixation and distraction devices were removed. Preoperatively, the deviation of the occlusal plane ranged from 8° to 13° (mean: 10.5°); the distraction distance ranged from 7 mm to 17 mm (mean: 13 mm). In two patients there was radiologic evidence of relapse 6 months after distraction, but no significant change in facial appearance was observed. Seven patients maintained a stable preoperative occlusal relationship and the preoperative lateral open bite was improved postoperatively in two patients. The postoperative occlusal plane was between 0° and 1° in every case.