A study of the risk and the prevention of root resorption during orthodontic treatment

正畸治疗过程中牙根吸收的风险及预防研究

基本信息

批准号：
07557282
负责人：
MITANI Hideo
金额：
$ 1.66万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

The purpose of this study was to examine the risk of root resorption during orthodontic treatment and develop the prevention method of that from the basic and the clinical background. Clinical studies showed almost 40% of patients that developed severe root resorption during orthodontic treatment had abnormally shaped roots before active treatment. To test the effects of deficiencies of mineral nutrients on the formation of roots and the development of tooth resorption during orthodontic tooth movement, 2 weeks-old Wistar rats were fed a low calcium diet during root development period and the molars were moved orthodontically. A hypomineralized dentin with interglobular dentin was observed in the experimental animals, but no significant difference was observed in the development of tooth resorption between control and experimental animals. Immunohistochemical studies showed cementblasts produced osteocalcin and glycosaminoglycans and have simillar characteristics with osteoblasts. The production of them was changed during orthodontic tooth movement and cementblasts suggested to be related with the formation of odontoclasts. In vitro studies showed human periodontal ligament (PDL) fibroblasts induced HSP 47,60,70 with the application of continuous compressive stress to protect cells from mechanical stress and regulated the formation of odontoclast-like cells from peripheral blood lymphocytes. In contrast, inhibitory effects of the topical administration of a bisphosphonate on root resorption incident to orthodontic tooth movement were observed in rats. These results indicate the risk of root resorption during orthodontic treatment may be related with the properties of the periodontium and the roots and some bone resorption inhibitory detergents can prevent it.

本研究的目的是探讨正畸治疗过程中牙根吸收的风险，并从基础和临床背景出发制定预防方法。临床研究表明，在正畸治疗期间出现严重牙根吸收的患者中，近 40% 在积极治疗前牙根形状异常。为测试正畸牙齿移动过程中矿质营养素缺乏对牙根形成和牙齿吸收发展的影响，2周龄Wistar大鼠在牙根发育期饲喂低钙饮食，并进行正畸移动磨牙。在实验动物中观察到牙本质矿化不足并伴有球间牙本质，但对照组和实验动物之间牙齿吸收的发展没有观察到显着差异。免疫组织化学研究表明，成骨细胞产生骨钙素和糖胺聚糖，并与成骨细胞具有相似的特征。它们的产生在正畸牙齿移动期间发生变化，并且牙骨质细胞被认为与破牙细胞的形成有关。体外研究表明，人牙周膜（PDL）成纤维细胞通过施加持续的压缩应力来诱导HSP 47、60、70，以保护细胞免受机械应力的影响，并调节外周血淋巴细胞形成破牙细胞样细胞。相反，在大鼠中观察到局部施用双膦酸盐对正畸牙齿移动所发生的牙根吸收的抑制作用。这些结果表明正畸治疗期间牙根吸收的风险可能与牙周组织和牙根的性质有关，一些骨吸收抑制清洁剂可以预防这种风险。