Mirabella A D, Artun J
Department of Orthodontics, University of Washington, Seattle, USA.
Am J Orthod Dentofacial Orthop. 1995 Jul;108(1):48-55. doi: 10.1016/s0889-5406(95)70065-x.
The purpose of this study was to identify risk factors for apical root resorption in adult orthodontic patients. Standardized periapical radiographs of maxillary anterior teeth and cephalograms made before and after treatment and treatment charts of 343 adults, representing groups of consecutively treated patients from four orthodontic practices, were examined. Apical root resorption was calculated by subtracting posttreatment tooth length measurements from the corresponding pretreatment measurements. Root width was measured from the mesial to the distal outline of the roots 4 mm from the apex. Root form was scored subjectively as normal, pointed, eroded, blunt, bent, and bottle shaped. Root movement was calculated from measurements of superimposed tracings of pretreatment and posttreatment cephalograms. Proximity of the central incisor roots to the palatal cortical bone was scored subjectively as present or absent. Severity of initial malocclusion and treatment variables were collected from the charts. Multiple linear regression analyses revealed that amount of root movement, long roots, narrow roots, abnormal root shape, and use of Class II elastics were significant risk factors. However, the statistical model had a low explained variance, strongly suggesting a weak prediction power. No association was found between type of initial malocclusion, treatment time, use of rectangular arch wires, proximity of the root to the palate or treatment with maxillary osteotomy, and root resorption. Endodontic treatment was a preventive factor.
本研究的目的是确定成年正畸患者根尖吸收的风险因素。对343名成年人治疗前和治疗后的上颌前牙标准化根尖片、头颅侧位片以及治疗图表进行了检查，这些成年人代表了来自四家正畸诊所的连续治疗患者群体。根尖吸收通过治疗后牙齿长度测量值减去相应的治疗前测量值来计算。从根尖4毫米处测量牙根从近中到远中的宽度。牙根形态主观评分分为正常、尖形、侵蚀形、钝形、弯曲形和瓶形。牙根移动通过治疗前和治疗后头颅侧位片叠加描迹的测量值来计算。主观评估中切牙根与腭侧皮质骨的接近情况是否存在。从图表中收集初始错牙合畸形的严重程度和治疗变量。多元线性回归分析显示，牙根移动量、长牙根、窄牙根、异常牙根形态以及使用II类弹性牵引是显著的风险因素。然而，统计模型的解释方差较低，强烈表明预测能力较弱。未发现初始错牙合畸形类型、治疗时间、使用矩形弓丝、牙根与腭部的接近程度或上颌截骨术治疗与牙根吸收之间存在关联。根管治疗是一个预防因素。
