rhBMPs对山羊下颌骨较大速率DO成骨的影响

目的研究在下颌骨较大速率牵引成骨术(DO)中应用重组人骨形成蛋白(rhBMPs)对成骨的影响,探讨下颌骨较大速率DO的可行性。方法12只山羊双侧下颌骨行DO,山羊及左右下颌骨随机化分为实验侧、对照侧,一只山羊作为正常标本。术中预置牵开间隙3.5mm,实验侧应用rhBMPs,延迟期为3d,牵引速率为1.5mm/d,分3次牵引,延长幅度为20mm。3、5、7、12周行大体、X线、骨密度、生物力学和组织学观察。结果延长幅度达到20mm,自固定期3周开始观察,牵引间隙新骨的再生形成及成熟改建仍是连续的骨愈合过程。固定期5周时,大体及X线观察表明实验侧已形成良好的骨皮质连续性,密度近于正常骨,而对照侧牵引间隙中间区却存在骨不连或间隙存在。组织学显示DO过程仍然是膜内成骨,对照侧牵引间隙中央可见中央区纤维连接、软骨改变,周边区可见新骨组织形成。生物力学三点弯曲实验显示实验侧在5周时接近正常骨,与对照侧有显著差异。骨密度随时间递增,实验侧在各时间点均高于对照侧。本实验条件下在5周后拆除牵引器较为可靠。结论较大速率DO的骨再生形成也是一个连续的膜内成骨过程。rhBMPs在较大速率和较大幅度DO中的应用能够加速骨的再生和愈合速...

Application of rhBMPs in Mandibular Lengthening at Higher Rate of Distraction in a Goat Model and Their Effect on Osteogenesis

Objective To study the feasibility and effect of application of recombinant human bone morphogenetic proteins (rhBMPs) in mandibular distraction by higher rate (1.5 mm/d) on osteogenesis in goats. Methods Twelve goats were used for bilateral mandibles DO and one goat was normal specimen. 3.5 mm gap was pre-set intraoperatively. rhBMPs were used in one side and the opposite side was the control. After a 3-day latency period, the distractor was activated at a rate of 1.5 mm per day (frequency: 3 times/day ) for 11 days and the total amount of lengthening reached 20 mm ultimately. The mandible were harvested at the interval of 3, 5, 7 and 12 weeks after comleting the distraction, and studied by of macrography, radiographic examination, dual-engineering X-ray absorptiometry (DEXA), three-point bending biomechanics test and histological examination. Results The new bone throughout the distracted zone in the experimental group appeared better than the contrary side at every time after completing the distraction and nearly normal cortical bone at 5 weeks. The difference of biomechanics test between experimental and control group at 5 weeks was significant, and bone mineral density (BMD) of the new bone in the experimental group was significantly greater than that in the control group at every time point and increase gradually with time extending. Conclusion The regeneration of new bone in distracted zone is a serial procedure and the mode of bone formation is primarily intramembranous osteogenesis at higher rate of distraction. Application of rhBMPs combined with reconstituted bone xenograft carrier in DO at higher rate of distraction will enhance the speed of bone formation and consolidation.So we think higher rate of distraction in this project is feasible.