SEGMENTAL MANDIBULAR RECONSTRUCTION BY DISTRACTION OSTEOGENESIS UNDERSKIN FLAPS

In five adult dogs, molars were extracted and skin flaps from the neck prepared for delayed transplantation. Two weeks later, a 25-mm segmen t of the mandible was excised with surrounding periosteum and gingiva. The mandible was stabilized with a reconstruction plate and the intra oral defect repaired with a pedicled skin flap. A proximal transport s egment was created and an external distraction device was applied. Aft er one week, distraction of the transport segment was begun at a rate of 1 mm/day. After distraction was completed, the lengthening applianc e was left in place for 12 weeks until the dogs were killed. Radiologi c and histologic examination revealed new bone at the distraction site . The intraoral skin flap was pushed out of the defect as distraction progressed. Bony union of the transport segment to the distal stump wa s not achieved due to intervening soft tissue. These results suggest t hat it is feasible to bridge a mandibular defect that is covered with a skin flap, with distraction osteogenesis.