Nakamura Masahiro, Kawanabe Noriaki, Kataoka Tomoki, Murakami Takashi, Yamashiro Takashi, Kamioka Hiroshi
Department of Orthodontics, Okayama University Hospital, Okayama, Japan.
Department of Orthodontics, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Hospital, Okayama, Japan.
Am J Orthod Dentofacial Orthop. 2017 Jun;151(6):1116-1124. doi: 10.1016/j.ajodo.2016.10.040.
Our objective was to elucidate the differences in treatment outcomes caused by the different mechanics of temporary anchorage devices (TADs) and Class III elastics in patients with Class III malocclusions.
Records of 23 patients with Angle Class III malocclusion were selected retrospectively. All had been treated with nonextraction comprehensive orthodontic treatment; 11 were treated with TADs and 12 with Class III elastics. Pretreatment and posttreatment lateral cephalograms were used for evaluation of the treatment outcomes. A paired t test and a Student t test were used for statistical analysis.
In both groups, proper overjet and Class I molar relationships were achieved, and the occlusal plane was rotated counterclockwise. In the elastics group, distal tipping of the mandibular molars, extrusion of the mandibular incisors and maxillary molars, clockwise rotation of the mandibular plane angle, and increased ANB angle were observed. In the TADs group, distal tipping and intrusion of the mandibular molars, bodily movement of the mandibular incisors, and reduced mandibular plane angle were observed.
In nonextraction treatment for Class III malocclusions, the mandibular plane angle was increased in the elastics group, whereas it was decreased in TADs group. Thus, we suggest that Class III elastics are preferred for low-angle, short-face patients, whereas TADs are preferred for high-angle, long-face patients.
我们的目的是阐明Ⅲ类错牙合患者中临时锚固装置（TADs）和Ⅲ类弹力牵引的不同力学机制所导致的治疗结果差异。
回顾性选取23例安氏Ⅲ类错牙合患者的记录。所有患者均接受了非拔牙综合正畸治疗；11例采用TADs治疗，12例采用Ⅲ类弹力牵引治疗。治疗前和治疗后的头颅侧位片用于评估治疗结果。采用配对t检验和学生t检验进行统计分析。
两组均实现了合适的覆盖和Ⅰ类磨牙关系，牙合平面逆时针旋转。在弹力牵引组中，观察到下颌磨牙远中倾斜、下颌切牙和上颌磨牙伸长、下颌平面角顺时针旋转以及ANB角增大。在TADs组中，观察到下颌磨牙远中倾斜和压低、下颌切牙整体移动以及下颌平面角减小。
在Ⅲ类错牙合的非拔牙治疗中，弹力牵引组的下颌平面角增大，而TADs组的下颌平面角减小。因此，我们建议低角、短面型患者首选Ⅲ类弹力牵引，而高角、长面型患者首选TADs。
