Bilateral mandibular distraction in adult dogs with an epiperiosteal distractor.

We tested the function and efficiency of a new intraoral, bone-borne distraction device for mandibular lengthening, and the effect of bilateral transsection of the inferior alveolar arteries on osteogenesis in adult dogs. Nine adult Beagles had bilateral complete mandibular osteotomies and epiperiosteal placement of the distractor. After 7 days, the mandibles were distracted at 1 x 1mm/day, 1 x 0.5 mm/day or 2 x 0.25 mm/day for 15 or 30 days, respectively. Hemimandibles were harvested after 1, 14, or 42 days consolidation and evaluated clinically, radiographically and histologically. The mean distraction achieved was 11 mm (range 4-16 mm). New bone formation and clinical stability increased with increasing consolidation time and was independent of the distraction protocol used. Osteogenesis at the distal and proximal mandibular fragments did not differ. In 10/18 distraction sites, wound dehiscences compromised osteogenesis. The new epiperiosteal distractor permitted successful distraction osteogenesis despite complete bilateral osteotomy with section of the medullary vessels in adult dogs.