Rapid orthopedic lengthening of the mandible in primates by sagittal split osteotomy and distraction osteogenesis: a pilot study.

This study proposes the development of an intraoral surgical approach to distraction osteogenesis to treat maxillofacial defects. Bilateral sagittal split osteotomies were made in the ascending ramus and body of the mandible of two adult cynomologus primates, and the dento-osseous segment was completely mobilized. A distraction device was fabricated from a Glen-Ross screw soldered between two mini bone plates. The bone plates were fixed by self-tapping screws to both right and left proximal and distal mandibular segments. Beginning 1 week postoperatively, both distraction plates were opened 1 mm every day until the mandible was advanced a total of 10 mm. Comparison of cephalometric radiographs and study casts prepared preoperatively, at the completion of the mandibular orthopedic advancement, and up to 12 weeks postdistraction, showed that mandibular advancement was successful and stable. There was radiographic evidence of bone filling the osteotomy sites, and there was no scar tissue formation or evidence of relapse.