一种新的咬合垂直距离升高动物模型建立方法及评价

Establishment and evaluation of animal model of increasing occlusal vertical dimension

目的探讨大鼠咬合垂直距离升高(iOVD)动物模型的可重复更好的建模方法,及OVD升高对大鼠牙体牙周、颞下颌关节及全身体重的影响。方法60只成年Wistar大鼠,平均分为对照组和iOVD组(双侧上颌后牙戴1.5mm咬合板),运用修复技术完成iOVD咬合板的制作和黏结,分别在实验3天、1周、2周、3周、4周处死动物。观察项目包括体重分析、头侧位X线片、头颅标本解剖、下颌磨牙区骨段及髁状突组织学切片观察等。结果两组大鼠体重增长差异无统计学意义(P>0.05)。头侧位X线片示iOVD组大鼠髁突位置前移,上切牙腭侧磨耗面发生改变。iOVD组大鼠磨牙根分叉区牙槽骨及髁状突中后区软骨出现组织学形态改建。结论采用修复技术可成功建立成年期大鼠咬合垂直距离升高动物模型,咬合板的戴入引起了牙体牙周组织和颞下颌关节髁状突软骨的组织适应性改建,但对全身营养摄入无影响。

Objective To establish repeatable animal models of increasing occlusal vertical dimension （iOVD） in adult rats; to evaluate the influence of iOVD on nutrition intake, periodontal tissue and tem.poromandibular joints. Methods 60 adult Wistar rats were randomly divided into two groups, the control group and iOVD group. The rats in iOVD group wore maxillary bilateral posterior dentition splints and those in the control group remained nature. With prosthodontic techniques, the resin splints of iOVD were made and bonded. The rats were sacrificed in 3 d, 1 w,2 w, 3 w,4 w after the experiment. Weight analysis, lateral head radiography, specimen anatomy and histological sections of tooth and temporomandibular joint （TMJ） were performed and results were evaluated. Results The weight curves for rats in the control and iOVD groups were basically uniform and the results of variance analysis showed no statistical difference after repetitive ts. In the rats of iOVD group occlusal deviation, unilateral masseter swelling and asymmetry dentition abrasion didn＇t occur. However, pathological changes and remodeling in periodontal tissue and temporomandibular joint were observed. Radiographs demonstrated that condyles moved forward and downward. The incisors gradually wore and erupted to compensate the increased OVD at 2 - 4 w. Conclusions The animal models of iOVD adult rats can be successfully established with prosthodontics techniques. The wear of occlusal splints induce the changes on periodontium and TMJ cartilage of adult rats. However, nutrition intake is unaffected.