课题背景：颌面骨的牵张成骨是近十几年来口腔颌面外科和整形外科领域骨畸形矫正和骨缺损修复的研究热点。目前应用较多的是内置式的、用螺旋杆机械施力的牵张器，但它存在着螺旋杆等外置部分、需间断加力、可能引起感染及面部瘢痕等缺点。研制完全内置，能靠自身弹力不间断加力的牵张器是最新研究方向之一。镍钛记忆合金（TiNi-SMA）牵张器就是这一研究方向的代表。

应用要点：保留部分松质骨的骨皮质切开术可根据需要调整骨组织阻力，使其与牵张力平衡，同时骨皮质切开术保留了髓内血供及舌侧骨膜，更有利于新骨的形成。因此，在使用镍钛记忆合金牵张器时，截骨方式的选择应根据缺损部位、缺损范围及软组织条件等实际情况综合考虑。

相关链接：已有学者利用镍钛形状记忆合金制成可持续自动牵张的牵张器，成功应用于牵张成骨的动物实验及临床。但关于镍钛记忆合金牵张器在颌面骨不同部位的不同截骨方式，与镍钛记忆合金牵张器弹力的相互平衡关系及对牵张成骨效应的影响，还需进行深入研究。

摘要
目的：镍钛记忆合金具有记忆性、耐磨性及生物相容性好等优点，与常规牵张成骨在截骨方式、生物力学上存在着不同。建立犬下颌骨矩形缺损的动物模型，探讨不同截骨方式下镍钛记忆合金牵张器的牵张成骨效果。
方法：实验于2005-10/12在中山大学动物实验中心完成。①实验材料：成年雄性Beagle犬8只，体质量12~14 kg。②实验过程：双侧下颌骨体制造1.5 cm×1.0 cm矩形缺损，并在近中形成相应大小的骨传送盘。左侧骨传送盘行颊舌侧全层截骨术，右侧骨传送盘行保留部分松质骨的皮质切开术，置入镍钛记忆合金牵张器。③评估：于术后1，4，7 d及9周拍摄X射线片并进行组织病理学检查，对比双侧牵张区新骨生成情况。
结果：8只犬均进入结果分析。①大体观察：所有动物术后创口无感染，愈合良好。②X射线检查：见右侧即骨皮质切开侧术后骨传送盘逐渐向缺损区移动，于术后7 d基本占据骨缺损区；左侧即颊舌侧全层截骨侧术后1 d骨传送盘已移位，术后7 d骨传送盘完全离开缺损区。③组织学检查:见9周后右侧牵张区形成新生骨质，符合膜内成骨，传送盘与近中牵张区形成骨性连接；左侧由于骨传松盘离开缺损区，牵张区与缺损区形成一较大的凹陷，未见明显新骨形成。
结论：采用保留部分松质骨的骨皮质切开术的截骨方式可成功建立犬下颌骨矩形缺损牵张成骨动物模型。
关键词：牵张成骨；镍钛记忆合金；下颌骨；骨缺损；犬；组织构建

曾融生，张朋，王成.镍钛记忆合金牵张成骨修复犬下颌骨缺损与不同截骨方式的关系[J].中国组织工程研究与临床康复，2008，12(2):217-220 [www.zglckf.com/zglckf/ejournal/upfiles/08-2/2k-217(ps).pdf]

Osteotomy with Titanium-Nickel shape memory alloy distracter for repairing mandibular defects in dogs

Abstract

AIM：Titanium-Nickel shape memory alloy (TiNi-SMA) has memory, abradability and good biocompatibility. It has different osteotomy methods and biomechanics from routine distraction osteogenesis. In this study, the dog models of mandibular defects were established to explore the effect of TiNi-SMA distractor with different osteotomy methods on mandibular distraction osteogenesis.
METHODS: The experiment was performed at the animal experimental center of Sun Yat-sen University from October to December 2005. ①Eight male adult Beagle canines of 12-14 kg were selected. A 1.5 cm×1.0 cm bone defect was made in bilateral mandible of each dog. The same size transport bone disc was created mesially by osteotomy on left side and corticotomy on right side. TiNi-SMA distractor was implanted to repair defect. ②One, four, and seven days, and nine weeks after operation, the canines were radiographed for histological analysis and bone formation was observed.
RESULTS: Eight dogs were all included in the final analysis. ①Gross observation found the wounds healed well without infection in all experiment dogs. ②X-ray examination showed the bone transport disc on the right side of corticotomy moved to defect area gradually after operation and filled defect area on the whole on the 7th day after operation; The bone transport disc dislocated 1 day after operation and separated from defect area totally on the 7th day after operation on the side of osteotomy (left side). ③Histological examination demonstrated bone formed in accordance with intramembranous ossification in distraction zone and bony connection between the transport disc and mesial mandible on right side; On the left side, there was a big defect at the area of both distraction and defect zone because of dislocated bone transport disc, and no obvious new bone regeneration was found.
CONCLUSION: Corticotomy can be used to establish a successfully canine model of mandibular distraction osteogenesis.

Zeng RS, Zhang P, Wang C.Osteotomy with Titanium-Nickel shape memory alloy distracter for repairing mandibular defects in dogs.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(2):217-220(China)
[www.zglckf.com/zglckf/ejournal/upfiles/08-2/2k-217(ps).pdf]