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Root Resorption in Maxillary Central Incisors during Active Orthodontic Treatment-A Radiographic Study-

主动正畸治疗过程中上颌中切牙的牙根吸收-放射学研究-

基本信息

批准号：
63570938
负责人：
WADA Takuro
金额：
$ 1.34万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63570938/
关键词：
Orthodontic Root Resorption Incisors 規格撮影歯牙移動口内法X線規格撮影法

项目摘要

The purpose of this study was to investigate whether it is possible to detect an early radiographic changes of root resorption in upper incisors during active orthodontic treatment. A newly occlusal technique for measurement of tooth length combined with lateral cephalogram was developed. Although experimental study with 10 dry skulls showed a good results to measure tooth lengths, clinical use for measurement of tooth length in patients was not satisfactory. The cause of failure in measurement was that a geometric factor, patients' open bite, ill-defined incisor edge, and so on were combined. The measurement of the thickness of periodontal space and lamina dura showed a good correlation with the observation of the occlusal radiograms.Out of registered 120 volunteer patients in this study, 36 patients were quit because of some reasons(e. g. . non-cooperation of the patients or orthodontists after registration, or the patients with cleft palate, occurrence of tumor). Forty-four patients were still in active orthodontic treatment. Subsequent 40 patients were analyzed this time. The duration for active orthodontic treatment was 3 to 31 months, mean 20 months. The radiograms were taken every 3 months during active orthodontic treatment. The final radiograms were taken at one month before or after starting the retention. The root resorption was clearly occurred in 26 patients(65%)and suspected in 6 patients(15%). The first detection of root resorption was from 3 months to one year or more. In the severe resorption cases, the timing of the first detection of root resorption was very early in the first radiogram. It is important for orthodontists to know that the early detection of root resorption sucgests the high risk of root resorption. Also the changes of lamina dura and periodontal space were different between root resorption patients and non-resorption patients. We will report about this point after this project is finalized.

本研究的目的是探讨是否有可能在正畸治疗过程中早期发现上切牙牙根吸收的影像学变化。提出了一种结合侧位头颅造影测量牙长的新方法。虽然10个干颅骨的实验研究显示测量牙长效果良好，但临床应用于患者的牙长测量并不令人满意。测量失败的原因是几何因素、患者开咬、切牙边缘不清等因素共同作用的结果。牙周间隙和硬膜厚度的测量结果与咬合x线片的观察结果具有良好的相关性。在本研究登记的120名志愿者患者中，有36名患者因某些原因(如：g。。患者或正畸医师登记后不配合，或腭裂患者发生肿瘤)。44例患者仍在积极进行正畸治疗。随后对40例患者进行了分析。积极正畸治疗时间3 ~ 31个月，平均20个月。在正畸治疗期间每3个月拍摄一次x线片。在开始留置前或留置后一个月拍摄最后的x线片。26例（65%）明显发生牙根吸收，6例（15%）疑似发生牙根吸收。首次发现牙根吸收的时间为3个月至1年以上。在严重的吸收病例中，第一次检测根吸收的时间在第一次x线片中非常早。对于正畸医生来说，早期发现牙根吸收是发生牙根吸收的高危因素，这一点很重要。牙根吸收组与非牙根吸收组的硬膜和牙周间隙变化也存在差异。这个项目完成后，我们会报告这一点。