ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of rhBMP-2 on bone formation of mandibular distraction osteogenesis in rabbits.</p><p><b>METHODS</b>Bilateral mandibular osteotomies were performed in 12 mature rabbits. 5 mg rhBMP-2 with the collagen carrier was implanted in the osteotomy site of one side of the mandibles. Only the collagen sponge was placed in the contra-lateral side as control. The mandibles of 8 rabbits were lengthened by 6mm using a custom-made distractor. At 4 weeks after the end of distraction, all animals were killed and the distracted calluses were harvested and processed for histological, scanning electron microscopic, as well as Ca/P ratio analysis.</p><p><b>RESULTS</b>The regenerated bone was found in the distraction gap after mandibular lengthening. The mandibular side treated with rhBMP-2 had greater amounts of new bone formation and earlier mineralization than contra-lateral side (non-rhBMP-2 treated).</p><p><b>CONCLUSION</b>Recombinant human BMP-2 appears to be able to accelerate bone formation of mandibular distraction osteogenesis in rabbits.</p>