SIMULTANEOUS MANDIBULAR AND MAXILLARY DISTRACTION IN HEMIFACIAL MICROSOMIA IN ADULTS - AVOIDING OCCLUSAL DISASTERS

Mandibular clongation by gradual distraction in patients with hemifaci al microsomia is a simple and effective procedure to correct facial as ymmetry. The two-pin system joined by a softer distracting screw achie ves elongation in vertical and sagittal directions as well as medial r otation. The changes in mandibular shape result in changes in dental o cclusion. These are minimal in children because of the rapid growth of the maxilla and can be corrected easily with minor orthodontic work. Mandibular distraction in adults with hemifacial microsomia, who usual ly have stable dental occlusion, produces good aesthetic results but a lso severe alterations in the occlusion requiring complex orthodontic treatment over a long period. To avoid this problem, an incomplete Le Fort I osteotomy is done simultaneously with the mandibular corticotom y. Intermaxillary fixation is done on the fifth postoperative day, and distraction is initiated. In a series of seven patients, the maxilla was distracted simultaneously with the mandible, preserving the preexi sting stable occlusion. Preoperative deviation of the occlusal plane f rom the horizontal in four patients, and deviation of 2 degrees persis ted in three. The distance from the inferior orbital fun tot he occlus al plane on the affected side was increased in all patients, achieving 100 percent correction (compared with the normal side) in four patien ts and 95, 96, and 97 percent in the other three.