Two cases of facial asymmetry with diagnosis of hemifacial microsomia treated by three internal distractors
to correct occlusal canting, shorten ramus and facial asymmetry were presented. The initial evaluation showed
hemifacial deficiency, occlusal and lip commissure canting. All of the clinical data showed characteristic of hemifacial
microsomia type 2 according to Pruzunsky’s classification. Three intraoral distractors were placed following a Le
Fort I osteotomy, left horizontal ramus osteotomy and right intraoral vertical ramus osteotomy. The modified
Le Fort I osteotomy was designed for the direction of distraction by clockwise rotation with anterior nasal spine as
center of rotation. Left side distractors were activated to lengthen left site segment but the right side distractor was
activated to compress right segment. Advancement of 6 mms of left ramus and 3.75 mms of left maxilla were
obtained within 2 week. In the completion distraction phase, both occlusal canting and shorten left ramus were
obtained. After the consolidation period, the distractors were removed under general anesthesia without any
complication. Furthermore the right side angle reduction and mandibular buccal osteotomy, advancement genioplasty,
left mandibular body augmentation with autogenous bone graft and nose augmentation with silicone material were
performed to improve the final esthetic. Long term post-operative follow up revealed the optimal occlusion with
significant improving in facial symmetry without any skeletal relapse detected.