【摘要】 ①目的　应用牵张成骨技术延长狗下颌骨动物模型 ,了解下颌骨牵张成骨过程及下颌骨牵张成骨新骨生成规律。②方法　 8只成年狗 ,按不同的牵张期和固定期分为 4组 ,每组 2只。于下颌第一磨牙后区 ,行下颌骨体部骨切开术 ,安置骨支持式口腔外部牵张器。潜伏期固定 7d后牵引 ,每天延长 1mm ,分 2次进行 ,分别于第 3,10 ,2 0和 2 0天停止牵张 ,并固定。分别于牵张期开始、结束及固定期结束摄取X线片。固定期结束时处死动物 ,取牵张区新骨行组织学检查。③结果　 4组动物下颌骨分别成功延长了 3,10 ,2 0和 2 0mm .X线片及组织学检查可见骨样组织、编织骨和板层骨形成、过渡及改建过程 ,并有软骨内骨化现象。④结论　下颌骨牵张成骨术其牵开区可得到良好的骨生成 ,新骨以膜内成骨为主 ,软骨内成骨为辅更多还原

【Abstract】 Objective\ The mandibular lengthening by traction osteogenesis was studied in canine model to understand the process of mandibular distraction osteogenesis and law of formation of new bone. \ Methods\ Eight adult dogs were divided into four groups, two for each group, based on different periods of distraction and fixation. Mandibular body corticotomies were performed, held in a neutral position for 7 days, and then lengthened at a rate of 0.5 mm per 12 hours for 3, 10, 20 and 20 days, respectively, using a unilateral external lengthening apparatus. The animals were killed on days 3, 20, 30 and 40, respectively, after completion of the fixation and traction. Results\ In the 4 groups, 3mm, 10mm, 20mm and 20mm lengthening were achieved. The results of radiographic and histological studies demonstrated that the distracted gap was filled with callus, which underwent a process of developing, transiting and remodeling of the osteoid, woven bone and lamellar bone. Endochondral ossification was also formed at the same time. \ Conclusion\ Perfect new bone formation was achieved in the area of mandibular distraction. The new bone was mainly membranous ossification, endochondral being the second.更多还原