坚固内固定对兔下颌骨发育影响的实验研究

摘要

目的 观察坚固内固定对兔下颌骨发育的影响.方法 选用70天龄新西兰白兔10只,右侧下颌骨为实验组,造成下颌骨体部骨折同时行钛板固定;左侧下颌骨为对照组,不造成骨折,仅植入定位钛钉.术后3个月取下颌骨进行大体观察、Micro-CT扫描及组织学观察.应用SPSS14.0软件包进行单因素方差分析.结果 实验组钛板固定区域颊侧骨皮质厚度、骨体积分数均小于对照组(P<0.05),骨密度的差异不大(P>0.05).两组之间下颌骨的生长量未见明显差异,所有动物未出现两侧下颌骨发育不对称、中线偏斜及咬合关系紊乱的现象.结论 坚固内固定对下颌骨发育无明显抑制作用,仅影响发育期下颌骨成骨质量,造成局部骨皮质厚度、骨体积分数不同程度的减小.%Objective To ohserve the effect of rigid internal fixation on mandibular growth in rabbits.Methods Ten 70-day-old white New Zealand rabbits were included in this study. Fractures were created in all of the right mandibles and fixed with titanium microplates and screws. The contralateral side served as the control,only being implanted two screws for location. General observation, Micro-CT scanning and histological observation of HE were studied 3 months after surgery. One Way ANOVA was performed using SPSS 14. 0 software package. Results The cortical wall thickness and bone volume fraction of the area where the titanium plate was fixed were smaller than the control group( P＜0. 05 ) , and the distinction of cortical density was not obvious( P＞ 0. 05 ) . The difference of the amount of growth in two groups were tiny. Mandibular asymmetry,midline shift and occlusion disorder were not found in all of the animals. Conclusion Rigid internal fixation doesn't restrict mandibular growth, but affects the quality of bone formation. The cortical wall thickness and bone volume fraction are decreased in varying degrees.