上颌骨前牵引对犬眶下神经的影响

目的:观察犬双侧上颌骨前牵引的不同时期眶下神经组织学结构的改变,探讨其对眶下神经的影响。方法:选12周龄杂种犬13只为实验对象,实验组12只,用特制牵引器进行上颌骨前牵引;对照组1只,未配戴牵引器。牵引过程包括15d牵引期和20d固定期,牵引力为800g。于术后不同时间点分组处死动物,取双侧眶下神经,制成常规切片,光镜下观察不同时期的神经组织形态。结果:随着牵引的进行,上颌骨明显前移,眶下神经出现明显病理变化,牵引结束时神经损伤最严重;固定期神经出现修复性变化。结论:双侧上颌骨前牵引对眶下神经可产生一定的损伤,但这种损伤是暂时的、可逆的,随着时间的延长,神经的形态结构可恢复正常。

Influence of maxillary protraction on infraorbital nerve of dog

Objective: To observe the histological changes of the dogs infraorbital nerves at different time during and after maxillary protraction. Methods: The animal model was established with thirteen 12-week mongrel dogs, which were randomly divided into the experimental group and the control. Rigid external distraxtor was used in experimental dogs for midfacial skeleton protraction. Distraction protocol included 15 days distraction and 20 days consolidation. The force used for midfacial protraction was 800 gram. The experimental animals were sacrificed at different time points postoperatively. Bilateral infraorbital nerves were obtained from the experimental and the control dogs. Histological sections were prepared, stained with HE, and observed under the light microscope. Results: The midfacial skelecton moved forward obviously in experimental dogs. Pathological changes were observed in the infraorbital nerves in experimental dogs. At the end of distraction, the changes of the infraorbital nerve become more obvious. During the period of consolidation, infraorbital nerve began to recover. Two months after the removal of the rigid external distractor, the nerves were observed as normal. Conclusions: Along with the midfical skeleton advancement by sutural distraction, deleterious changes appeared in the infraorbital nerves, but it is temporary and reversible.