OBJECTIVETo study the application of extraoral distraction devices in correction of various maxillo-mandibular deformities.

METHODSFrom 1997, 11 cases with various maxillo-mandibular deformities were corrected by distraction devices of designed by myself. 7 cases of then were the patients with cleft palate who have severe secondary maxillary hypoplasia. 1 case with micrognathia, 1 case with partial mandibular mentum defect, 1 case with lateral deviation of micrognathia and 1 case with hemimandibular hypertrophy. The mandibles were elongated, from 12 mm to 20 mm, the maxillae were elongated from 7 mm to 22 mm, the vertical mandibular distraction was 15 mm.

RESULTSAll cases were corrected satisfactorily and haven't any complications. In 1 cases the 1 Kischners pin had been pull out by loosen during distration. 4 Kischners pin were curved during vertical mandibular distration. Another case the maxillary hypoplasia appeared edge-to-edge and mild open occlusion after 4 weeks fixation.

CONCLUSIONThe extraoral distration osteogenesis provides a new method with many advantages for those maxillo-mandibular deformities that are difficulty corrected by ordinary orthognathic surgery.