正畸矫治对根管治疗牙齿牙根吸收程度影响的CBCT研究

目的利用CBCT评价正畸治疗对根管治疗牙齿牙根吸收程度的影响。方法选择上下颌牙齿轻中度拥挤的成年患者16例,患者上颌前牙中至少有一颗已行根管治疗。使用0.558 8 mm槽沟的MBT托槽进行非拔牙矫治。于治疗前、后分别拍摄头颅CBCT,并分别测量根管治疗牙齿以及对侧同名牙齿的长度。采用配对t检验进行统计分析。结果 16例患者一共有18颗上颌前牙接受过根管治疗,其中包括6颗中切牙,8颗侧切牙,4颗尖牙。平均治疗时间为(18.3±2.6)个月。治疗前,已行根管治疗牙齿牙根平均长度(22.68±2.14)mm;治疗后,牙根平均长度为(21.98±2.05)mm。治疗前,对侧同名活髓牙牙根平均长度(22.61±2.01)mm;治疗后,牙根平均长度为(22.01±2.37)mm。两组差别无统计学意义。按照牙位单独分析,亦无统计学差异。结论利用CBCT能够很好地观察正畸治疗后牙根吸收的情况。在轻中度拥挤非拔牙的病例中,正畸治疗并不会增加上颌前牙已行根管治疗牙齿牙根吸收的风险。

Cone beam computed tomography study on the apical root resorption after orthodontic treatment in root-filled teeth

Objective To investigate whether root-filled teeth would suffer external apical root resorption after orthodontic treatment compared with vital pulp teeth by CBCT ( cone beam computed tomography ) . Methods 16 adult patients with slightly-moderately crowded teeth were selected. At least one of each patient's maxillary anterior teeth had been treated with root canal treatment. 0. 5588 mm MBT bracket (3M Unitek) was applied to the non-extraction treatment. The CBCT images were collected, and the lengths of the treated tooth and the contralateral tooth were measured using axial-guided navigation before and after treatment. The statistical differ-ence was compared using the paired t-test. Results A total of 18 maxillary anterior teeth, including 6 central incisors, 8 lateral inci-sors, and 4 canines, had received root canal treatment among 16 patients. The average treatment duration was (18. 3 ± 2. 6) months. Before treatment, the length of posterior root-filled teeth was (22. 68±2. 14) mm, and the length was (21. 98±2. 05) mm after treat-ment. The length of the contralateral vital pulp tooth was (22. 61±2. 01) mm before treatment, and after treatment, the length was (22. 01±2. 37) mm. There was no statistical difference in root length between filled and vital roots in either pre-orthodontic or post-or-thodontic treatment. Similar results were also observed on the stratified analysis by the type of teeth. Conclusion CBCT is a good way to observe apical root resorption. In non-extraction cases with lightly-moderately crowded teeth, orthodontic treatment will not increase the risk of apical root resorption of the root-filled upper anterior teeth.