Maxillo-mandibular distraction osteogenesis for hemifacial microsomia in children.

To obviate or lessen the long period of use of orthodontic appliances after distraction for hemifacial microsomia in the mixed dentition patients, simultaneous maxillo-mandibular distraction osteogenesis has been performed in 10 patients aged 7 to 12 years with hemifacial microsomia. In these patients, there were two cases of type I, five cases of type IIa, and three cases of type IIb. A uniplanar internal distraction device was used in all cases. After maxillary Le Fort I osteotomy and mandibular ramus osteotomy, a uniplanar internal distraction device was attached to the mandible. On days 5 to 6 after surgery, distraction of 1 mm per day was started. Rigid intermaxillary fixation (IMF) using soft wires was performed at the distraction and was retained for 1 hour. Except for this period, rigid IMF was released. Distraction length ranged from 10 to 21 mm. After the distraction, a slight lateral crossbite in one case and a slight occlusal change in two cases, which did not necessitate the particular orthodontic treatment, were noted. Postoperative follow-up ranged from 16 to 40 months. The postoperative clinical course was uneventful thereafter. Maxillary growth impairment after the osteotomy has been obscure because of the short postoperative period. This procedure is effective for obviating or lessening the long duration of use of orthodontic appliances in the mixed dentition period of 7 to 14 years of hemifacial microsomia.