骨皮质切开加速大鼠正畸牙移动的机制研究

The mechanism of corticotomy accelerating orthodontic tooth movement in SD rats

目的 :研究骨皮质切开术加速大鼠正畸牙移动的组织学改建机制。方法 :选用健康未孕雌性Sprague-Dawley(S-D)大鼠48只,随机分为骨皮质切开手术组和对照组。在手术组大鼠行骨皮质切开术,对照组大鼠行对照手术后,构建正畸牙移动模型。在牙移动0、1、3、7 d分别处死2组大鼠各6只。测量牙移动距离并制备组织学切片,行抗酒石酸酸性磷酸酶(TRAP)染色和核因子κB受体活化因子配体(RANKL)免疫组织化学检测。采用SPSS16.0软件包对数据进行统计学分析。结果:骨皮质切开术可在牙移动第1天及3 d后加速正畸牙移动,而牙移动3 d时2组大鼠牙移动距离无显著差异。牙移动第3天和第7天,手术组大鼠压力区破骨细胞数目均显著高于对照组(P<0.05),手术组压力区RANKL的表达也显著高于对照组。结论:骨皮质切开术可加速大鼠正畸牙移动,这可能是由于牙周组织中RANKL高表达介导的破骨增强所致。

PURPOSE： To study the influences of corticotomy on orthodontic tooth movement （OTM） and the underlying mechanism in rats. METHODS： Forty-eight female Sprague-Dawley rats were randomly assigned to corticotomy group （Cort, 24 rats） or sham-corticotomy group （Sham, 24 rats）. All rats were subjected OTM after corticotomy or sham surgery. 6 rats of each group were sacrificed at 0, 1, 3 and 7 day of OTM. OTM were measured with an electronic digital caliper. Osteoclasts were counted in pressure side with TRAP. RANKL were measure by IHC at pressure side. The data were analyzed with SPSS 16.0 software package. RESULTS： OTM at the 1 and 7 day in Cort group increased compared with sham group. Number of TRAP positive osteoclasts in pressure side increased in Cort group at the 3 and 7 day. Expression of RANKL in pressure side also increased in Cort group at the 3 and 7 day. CONCLUSIONS： Corticotomy accelerates OTM in rats and it may result from promoted bone resorption via increased RANKL expression in periodontal tissue.