牵张成骨延长山羊下颌骨后下齿槽神经的组织学变化

Histological changes in the inferior alveolar nerve following mandibular osteodistraction in goats.

目的 :研究下颌骨牵张成骨术后不同时间内下齿槽神经的组织学改变。方法 :对 8只成年山羊行双侧下颌体骨皮质切开术 ,经口外安置自行研制的下颌牵张器 ,以每天 1mm的速率向前牵引延长其中 6只山羊的下颌骨10mm。于牵张结束后第 2、4、8周各处死 2只动物 ,取双侧下齿槽神经作组织学检查 ,另 2只未牵张的山羊作对照。结果 :下齿槽神经受牵张力作用发生了一定程度的沃勒变性 ,主要表现为髓鞘肿胀、碎裂及轴索数目减少。但随着固定时间的延长 ,受损神经纤维逐渐得以再生。结论 :下颌骨牵张成骨术后下齿槽神经发生了轻度的退行性变 。

Objective: To investigate the changes in the inferior alveolar nerve following mandibular lengthening by distraction osteogenesis. Methods: Eight adult goats underwent bilateral mandibular corticotomies, and the mandibles in 6 goats were lengthened using custom-made distractor at a rate of 1mm/d for 10 days. 2 goats were killed respectively at 2, 4 and 8 weeks after the completion of distraction. The other 2 nondistracted animals were served as control. The inferior alveolar nerve specimens were harvested and processed for histological examination. Results:The mandibles were lengthened successfully in 6 distracted goats. At 2 weeks postdistraction, moderate degeneration changes in the inferior alveolar nerve were observed. With consolidation progression, the nerve gradually recovered its normal structure. Conclusions: Mild or moderate morphological changes in the inferior alveolar nerve were found following mandibular osteodistraction. However, the nerve degenerative alterations may be reversible when a proper rate of distraction is used.