Effects of BMP on a rhythm of rabbit mandibular distraction osteogenesis

Oh, Seung Hwan; Min, Seung Ki; Keon, Kyong Hwan; Choi, Jea Young; Lee, Kyong Seuk

Abstract

Distraction osteogenesis is a well-established technique of endogenous tissue engineering. The biomechanical factors throught to affect the quality of the distraction regenerate include the latency, rate, rhythm, and consolidation period. In an effort to understand the impact of these parameters on regenerate bone formation, this study was designed to decipher the most adaptive response in a rabbit model of mandibular distraction osteogenesis. Eight rabbits were divided into 4 subgroups based on variation in the distraction rate(0.35mm/day, 0.7mm/day, 1.05mm/day, 1.4mm/day). And each subgroup were divided into 3 subgroup based on in BMP application(BMP group, tissue adhesive group, no treatment group). All group were distracted to total 4.2mm, after 5 days latency periods. After a 14-day consolidation period, the mandible were harvested, decalcified, and sectioned. A standardized histologic ranking system, radiolography, histology and clinical examination were used to evaluate the effect of distraction rate on the adaptive response of the regenerated bone according to BMP application. In this study, we have demonstrated that distraction rates up to 1.05mm per day stimulated regenerate bone formation, whereas greater distraction rates produced a less bone formation ability. But when BMPs applicated on osteotomy site, distraction rate of 1.4mm per day stimulated bone remodeling and similar to other control group of 1.05mm/day distraction and 0.7mm/day distraction. Thus we believe that BMPs facilitates new bone formation and shorten the total consolidation periods of the distracted bone on mandibular distraction osteogenesis in rabbits.