骨质疏松大鼠正畸牙齿移动模型中牙根吸收的比较研究

Comparative research of tooth root resorption in process of orthodontic teeth movement in ovariectomized rats

目的观察骨质疏松大鼠牙齿移动模型中,牙根吸收与体内雌激素水平的关系。方法 45只2个月龄雌性SD大鼠随机分为3组,每组15只,分别接受卵巢切除术,卵巢切除术后补充雌激素和假卵巢切除术处理,待骨质疏松模型建立后,3组大鼠均在上颌第一磨牙和切牙之间安置拉簧,力值0.784 N,分别于加力后的第5天、第10天和第14天各组处死5只大鼠,取上颌第一磨牙处标本制作切片,苏木精-伊红染色,处死前取血测定体内雌激素水平。结果各组标本均可观察到牙根吸收现象,而且在骨质疏松组更为普遍,程度也更重。结论骨质疏松时,正畸牙根吸收具有更大的风险性,体内雌激素水平的高低是影响正畸牙移动时,牙根吸收的一个重要因素。

Objective To study the possible relationship of root resorption and estrogen level in the process of orthodontic teeth movement in ovariectiomized rats.Methods Forty five 2-month-old female SD rats were divided randomly into three groups,15 rats per group（osteoporosis group,estrogen group and control group）.When osteoporosis was established,each rat was placed with a coil spring between the upper first molar and upper incisors with forces of 0.784 Newton.Every five rats were killed on the fifth day,the tenth day and the fourteenth day in each group respectively and the specimens were made at the root area of upper first morlar.In addition,blood（4 ml） was collected through abdominalaorta before execution and placed on 4 ℃ for 1 hour.After centrifugation,the plasma was analyzed for estrogen by RIA.Hematoxylin and eosin staining were used to observe the histological changes of the roots.Results Root resorption was commonly observed in each group.The prevalence of EARR rose significantly in the osteoporosis group as well as increment of root resorption.Conclusions Orthodontic teeth took more risk in root resorption for osteoporosis patients.The estrogen level in blood was one of the important factors which could influence root resorption during orthodontic treatment.