应用内置钛镍记忆合金牵张器在下颌骨牵张成骨的初步研究

目的　探索利用钛镍记忆合金牵张成骨增高下颌牙槽嵴和修复下颌骨节段性缺损的可行性。方法　 2 0只成年杂种犬分为 5组 ,Ⅰ组和Ⅱ组进行牵引成骨增高下颌骨牙槽嵴 ,Ⅲ组和Ⅳ组进行牵引成骨修复下颌骨缺损 ,Ⅴ组作为对照。牵引成骨用自行设计制作的内置型钛镍合金牵张器 ,在牵张手术前及术后 1、5、13周拍X线片 ,分别在牵张完成后 1、3个月处死动物 ,进行组织学研究。结果　钛镍牵张器显示了良好的组织相容性 ,自动完成牵引骨形成 ,牵张器安置完成后骨块即开始移动 ,X线片可见牵张完成后 1个月牵张区骨密度增高 ,有新骨生成 ;3个月时新生骨密度与周围骨接近 ,有效地增加了牙槽嵴的高度和初步修复了下颌骨的节段性缺损。组织学观察可见牵张区新骨形成良好。结论　内置自加载钛镍记忆合金牵张器自动牵引成骨是一种具有良好应用前景的简便实用的牵引成骨技术。

Study on mandibular distraction osteogenesis by TiNi-SMA distractor

Objective To discuss the possibility of augmenting mandibular alveolar ridge and reconstructing mandibular segmental defect by distraction osteogenesis(DO) using titanium nickel shape memory alloy (TiNi SMA) distractor. Methods Twenty adult hybrid canines were divided into five groups.Distraction osteogenesis for mandibular alveolar ridge augmentation was done in the first and the second group,and distraction osteogenesis for reconstruction of mandibular defects was performed in the third and the fourth group.The fifth group was control.The embedded distractor of the latest design for distraction osteogenesis was made by TiNi SMA.The radiographs were taken on before operation,and 1,5,13 weeks after the operation.The animals were killed at one and three months after distraction and histological examination was taken.Results The histocompatibility of TiNi SMA distractors was very well.Distraction osteogenesis was completed automatically.The transported segments moved immediately after the distractors were inserted.After one month of distraction,the radiographs showed the regenerating bone in distraction gap.The new bone and the normal bone could not be differentiated clearly three months after distraction.The canine mandibular posterior alveolar ridge was augmented and the mandibular defects were reconstructed by distraction osteogenesis using TiNi SMA distractor.Histological sections showed there was new bone formed in distraction gaps.Conclusion Distraction osteogenesis using embedded self loading TiNi SMA distractor could be a hopeful and useful technique.