咬合垂直距离升高对大鼠颞下颌关节组织形态学的影响

The influence of increased occlusal vertical dimention on the tempromandibular joint histomorphology in rats

目的观察咬合垂直距离升高后成年大鼠颞下颌关节的组织形态学改变。方法将12只成年雄性Wistar大鼠随机等分为对照组和咬合升高组(光固化复合树脂合垫升高后牙咬合),7 d后处死大鼠,取所有动物的颞下颌关节行HE染色光镜观察,并采用计算机辅助图像分析系统测量关节盘和髁突软骨前、中、后部的厚度。结果实验7 d后,两组动物的体重无明显差异,关节盘各部的厚度亦无明显改变(P>0.05);而咬合升高组大鼠髁突前、中、后部软骨全层的厚度均大于对照组(P<0.05);中带髁突软骨排列紊乱。结论 7 d的咬合升高可以影响成年大鼠髁突软骨的组织形态,局部出现关节炎样改变。

Objective To observe the increased occlusal vertical dimension（iOVD） on the tempromandibular joint（TMJ） histomorphology in adult rats.Methods 12 adult male Wistar rats were equally divided into control group and iOVD group（cementing an splint made of light-curing composite resin on the lower molars）.All the animals were killed after 7 d and all the TMJs were collected which were given hemotoxylin-eosin stained for analysis of anterior,middle,posterior band depth of disc and condyle as well as observation of TMJ histomorphology.Results There were no obvious change of body weight and disc depth in each section between the two groups（P 0.05）.The anterior,middle,and posterior-condyle depth of iOVD group increased and reached an significant difference compared with the control group（P 0.05）.In addition,HE staining showed disordered arrangement in middle section in iOVD group.Conclusion 7-day-iOVD has an influence on the histomorphology of TMJ in adult rats whereas arthritis-like change occurred partially.