Pandis Nikolaos, Nasika Maria, Polychronopoulou Argy, Eliades Theodore
Department of Pediatric Dentistry, School of Dentistry, University of Athens, Athens, Greece.
Am J Orthod Dentofacial Orthop. 2008 Nov;134(5):646-51. doi: 10.1016/j.ajodo.2007.01.032.
Our aim was to comparatively investigate the amount of external apical root resorption (EARR) between conventional and passive self-ligating brackets.
Ninety-six patients were selected from a pool of patients satisfying the following inclusion criteria: no evidence of resorption on the pretreatment panoramic radiographs; no contributing history of trauma; no dilacerations of lateral incisor roots, maxillary anodontia, and impacted canines; complete root formation at the start of treatment; intact and caries-free maxillary incisors; and no endodontically treated incisors. Patients received treatment with either a passive self-ligating bracket system or a conventional edgewise appliance, both with a 0.022-in slot. EARR of the maxillary incisors was evaluated on panoramic radiographs, taken before and after orthodontic treatment measured in millimeters. Distortion of measurements caused by panoramic radiographs was investigated by using a calibrated periodontal probe attached to the lateral incisor, and the extent of magnification was estimated to be 14%. Statistical comparisons of EARR between appliance type, age, sex, extraction treatment, and duration of treatment were investigated with univariate and multivariate regression modeling.
Overall, no difference was found in the amount of EARR between appliance systems. Age, sex, and extraction treatment were not reliable predictors of EARR, but a positive association between EARR and duration of treatment was observed.
No difference should be expected for root resorption between conventional and passive self-ligating brackets.
我们的目的是比较研究传统矫治器与被动自结扎矫治器的根尖外吸收（EARR）量。
从符合以下纳入标准的患者群体中选取96例患者：治疗前全景X线片无吸收迹象；无外伤史；侧切牙根无弯曲、上颌无牙症及阻生尖牙；治疗开始时牙根完全形成；上颌切牙完整且无龋；切牙未接受过根管治疗。患者分别接受被动自结扎矫治器系统或传统方丝弓矫治器治疗，两种矫治器均采用0.022英寸槽沟。在正畸治疗前后拍摄全景X线片，评估上颌切牙的EARR，以毫米为单位测量。通过将校准的牙周探针附着于侧切牙来研究全景X线片引起的测量失真，估计放大率为14%。采用单变量和多变量回归模型对矫治器类型、年龄、性别、拔牙治疗及治疗持续时间之间的EARR进行统计学比较。
总体而言，两种矫治器系统的EARR量没有差异。年龄、性别和拔牙治疗不是EARR的可靠预测因素，但观察到EARR与治疗持续时间呈正相关。
传统矫治器与被动自结扎矫治器在牙根吸收方面不应预期有差异。
