膜引导辅助弹力牵引成骨重建节段缺失下颌骨的实验研究

目的利用膜引导骨再生技术促进记忆合金牵引器弹力自动牵引成骨进程。方法手术截除杂种犬一侧下颌骨2．5-4．0cm骨段，按bi-focal牵引成骨原理安置记忆合金牵引固定装置，并将聚四氟乙烯膜覆盖于骨膜剥离的下颌骨颊侧面；术后3个月取下颌骨观察并测量骨密度和强度。结果节段缺失下颌骨得到重建，传送盘前后各形成1．5-2．5cm再生骨段；新骨高度及厚度接近正常下颌骨，骨密度和强度接近或超过正常骨半量值。结论膜引导技术可以避免骨不连，加快弹力牵引再生骨的骨化成熟过程。

Segmental mandibular reconstruction by elasticity distraction osteogenesis associated with guided bone regeneration

Objective To accelerate distraction osteogenesis by utilizing guided bone regeneration technique, and to improve the automatic process of canine segmental mandibular reconstruction by elasticity distraction osteogenesis using shape memory metal alloy distractor. Methods Adult hybrid canines were used. Osteotomy was performed to remove a bone segment of 2. 5-4.0 cm in one side of the mandible. Mandibular fixation devices and shape memory metal alloy distractor were secured according to the principles of bi-focal distraction technique. A piece of ePTFE membrane was sutured to cover the buccal side of bone defect and osteotomy gap of transport disc, where the periosteum was peeled for exposing mandible in operation. Then the incisions were totally closed. The canines were sacrificed 3 months later to harvest the mandibles for morphological observation and measurement of bone density and intensity. Results The shape memory metal alloy distractor performed distraction osteogenesis automatically and reconstructed the mandibles with bone defect. A regenerated bone segment of 1.5-2. 0 cm was formed in the compression region between transport disc and contralateral mandibular end. The new bone in both of distraction and compression regions had similar height and thickness with normal mandible. Moreover the new bone density and intensity were rather satisfied. Conclusions Membrane guided bone regeneration can avoid bone asynthesis commonly caused by cicatrization of soft tissue in the bone defect, and accelerate ossification and maturation of new generated bone.