Abstract:

Objective　To study the effects of rhBMP-2 on bone formation of mandibular distraction osteogenesis in rabbits. Methods　Bilateral mandibular osteotomieswere performed in 12 mature rabbits. 5 mg rhBMP-2 withthe collagen carrierwas im- planted in the osteotomy site of one side of the mandibles. Only the collagen sponge was placed in the contra-lateral side as con- trol. The mandibles of 8 rabbitswere lengthened by 6mm using a custom-made distractor. At 4 weeks after the end of distraction, all animalswere killed and the distracted calluseswere harvested and processed for histological, scanning electron microscopic, as well as Ca/P ratio analysis.Results　The regenerated bone was found in the distraction gap after mandibular lengthening. The mandibular side treated with rhBMP-2 had greater amounts of newbone formation and earliermineralization than contra-lateral side (non-rhBMP-2 treated).Conclusion　Recombinant human BMP-2 appears to be able to accelerate bone formation of mandibular distraction osteogenesis in rabbits.

Key words: mandibular osteo-distraction, recombinant human BMP-2, new bone formation