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大量研究表明在正畸治疗中存在着牙根吸收。通常牙根吸收较轻微,但也有少量患者会发生严重根吸收。一般认为:正畸治疗前先存的根吸收是引起正畸治疗中根吸收的诱因,并与个体差异,矫治器类型及矫治力大小有关。本研究目的即为了观察当矫治结束,矫治器去除后,根吸收是继续进展还是停止了。材料和方法100例患者,男性27例,女性73例。平均年龄13.6岁,平均疗程2.2年。正畸治疗前、后及治疗结束后三个月各拍一套全日牙片。并将牙根吸收分成4个等级,读片并分析。I°:牙根长度与治疗前一致,但根尖不规则;Ⅱ°:根吸收少于2mm,Ⅲ°:根吸收多于2mm,不超过根长的1/3;Ⅳ°:根吸收超过根长1/3.结果52%为Ⅰ°根吸收;40%为Ⅱ°根吸收;7%Ⅲ°根吸收;Ⅳ°根吸收仅为1%。另外,X 线片上可
Numerous studies have shown that root resorption exists in orthodontic treatment. Usually the root absorption is minor, but there are also a small number of patients will have serious root resorption. It is generally believed that the pre-existing root resorption before orthodontic treatment is the inducing factor of root resorption during orthodontic treatment, and is related to individual differences, appliance type and orthodontic force. The purpose of this study was to see if the root resorption continued or stopped after the appliance was removed when the treatment was over. Materials and Methods 100 patients, 27 males and 73 females. The average age of 13.6 years, the average course of 2.2 years. Orthodontic treatment before and after the treatment and three months after the shoot each set of all-day toothpicks. And root resorption is divided into four levels, read and analyze. I °: root length consistent with treatment, but irregular root tip; Ⅱ °: root absorption less than 2mm, Ⅲ °: root absorption more than 2mm, no more than 1/3 of the root length; Ⅳ °: Length 1/3 .Results 52% absorption of Ⅰ ° root; 40% absorption of Ⅱ ° root; 7% Ⅲ ° root absorption; Ⅳ ° root absorption was only 1%. In addition, the X-ray film can be