Repeated mandibular lengthening in Treacher Collins syndrome: a case report.

A patient with mandibular hypoplasia associated with Treacher Collins syndrome was treated by bilateral distraction osteogenesis. Since less than optimal length was provided by the first distraction, a second corticotomy was performed in the newly formed bone 6 months after the first distraction. Thus bone gained by distraction osteogenesis was subjected to distraction once again. New bone formation occurred after the second lengthening. This case illustrated that distraction osteogenesis may be applied to the mandible at the site of previous distraction.