Distraction osteogenesis for mandibular advancement.

The purpose of this study was to investigate the possibilities of distraction osteogenesis to correct mandibular hypoplasia. Fourteen young patients (mean age 14.1 years) with a proven resistance to initial, functional orthodontic therapy, were treated by means of bilateral intraoral distractors. The corticotomy was performed in the region of the third molar. The latency time was six days and the stabilization period six weeks. In all cases the planned lengthening of the mandible and class 1 occlusion were achieved. Seven patients required additional elastic band traction to close a mild open-bite directly after active distraction. In the first seven patients, insufficient mobilization at the site of the corticotomy had resulted in a broken distraction rod in two patients and incomplete distraction of the lingual cortex in one patient. Adequate mobilization at the site of the corticotomy prevented these problems in later cases. No permanent sensory disturbances were seen. Twelve patients finished their orthodontic treatment within six months after distraction.