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.

这项研究的目的是检查正畸治疗期间根部吸收的风险，并根据基本和临床背景开发预防方法。临床研究表明，在正畸治疗期间，几乎40％的患者在主动治疗前具有异常形状的根。为了测试矿物营养物质缺乏对根形成和正畸牙齿运动过程中牙齿吸收的影响，在根发育期间喂养2周大的Wistar大鼠钙饮食中的低钙饮食，并且磨牙在正畸形上移动。在实验动物中观察到了与叶间牙本质的低矿化牙本质，但在对照动物和实验动物之间的牙齿吸收发展中没有观察到显着差异。免疫组织化学研究表明，牙骨质生产骨钙素和糖胺聚糖，具有成骨细胞的类似特征。它们的产生在正畸牙齿运动过程中发生了变化，并建议与牙牙形成相关的水泥母细胞。体外研究表明，人类牙周韧带（PDL）成纤维细胞诱导HSP 47,60,70，并应用连续压力应激以保护细胞免受机械胁迫的影响，并调节了甲状腺样细胞的形成外周血液淋巴细胞。相反，在大鼠中观察到双膦酸盐局部给药对正畸牙齿运动的根部吸收入射的抑制作用。这些结果表明，正畸治疗期间根部吸收的风险可能与牙周和根的特性以及某些骨吸收抑制性洗涤剂可以预防。