下颌骨牵引成骨术对兔下牙槽神经的影响

目的观察牵引成骨术的不同牵引速度和距离对下牙槽神经的影响。方法新西兰白兔16只,以不同的牵引速度和牵引距离组合,随机分成5组。通过肉眼观察、X线片及电生理检查、组织学观察等了解下颌骨成骨及下牙槽神经再生情况。结果以2.0mm/d速度牵引下颌骨会产生骨不连接,以1.5mm/d速度牵引颌骨15mm,虽可获得良好的成骨,但可造成下牙槽神经不可逆性的损伤。结论下颌骨牵引成骨术的速度宜控制在0.5～1.5mm/d范围内;当牵引距离较小时,可适当加大牵引速度以提高牵引效率,当牵引距离较大时,应调小牵引速度,以减小对下牙槽神经的损伤。

Effects of mandibular distraction osteeogenesis on rabbit inferior alveolar nerve

Objective To discuss possible methods to enhance the efficiency of distraction osteogenesis and avoid the injury to the inferior alveolar nerve (IAN) following mandibular distraction osteogenesis at different rates and with different lengths. Methods 16 New Zealand rabbits were randomly divided into 5 groups at different rates and with different lengths. The evaluation of the regenerated bone and IAN included clinical, radiological, electrophysiological and histological aspects. Results A distraction rate of 2.0 mm/d resulted in nonunion of the distraction gap. After mandibular lengthening to 15mm at 1.5 mm/d, the regenerated bone was well formed, but the IAN showed irreversible injury. Conclusion The suitable rates of mandibular distraction osteogenesis should be limited between 0.5 mm/d and 1.5 mm/d. When the length of distraction was shorter, properly increasing the rate would be fit. When the length of distraction was longer, one should decrease the rate to reduce the IAN injury.