OBJECTIVETo study the combination of Mandibular distraction and orthognathic techniques for the reconstruction of adult hemifacial microsomia.

METHODSThe three-dimensional CT reconstruction data was used with Mimics for preoperation design. The osteotomy location, distraction vector, distraction distance were decided before operation with a surgical guider. At the first stage, internal distractor was implanted after ostetomy through an extra-oral approach. The distraction begun 5-7 days after operation with a frequency of 1 mm/day. After distraction, the distractor was maintained for 3-6 months. At the second stage, the distractor was removed. Le Fort I osteotomy was performed in order to correct the cross-bite and improve the facial contour. Usually, bone graft was inserted into the gap after Le Fort I osteotomy. The genioplasty was also performed if necessary.

RESULTS9 cases of adult hemifacial microsomia with severe mandibular deviation were treated. The facial asymmetry were improved greatly. 1 patient suffered an wound infection in the maxillary region after Le Fort I osteotomy and healed uneventfully with wound irrigation.

CONCLUSIONSMandibular distraction combined with orthognathic surgery is an effective procedure for adult hemifacial microsomia with complicated mandibular hypoplasia.