Zhou W, Wang L, Wang L, Wang Y H, Zhao C Y
Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University & Institute of Stomatology, Nanjing Medical University, Nanjing 210029, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2022 Jun 9;57(6):611-617. doi: 10.3760/cma.j.cn112144-20210716-00332.
To analyze the external root resorption of incisors caused by maxillary canine impaction, and to explore the changes of incisor external root resorption after orthodontic treatment. Twenty-four patients with impacted maxillary canines leading to external root resorption of incisors treated in Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University from July 2011 to January 2019 were selected. The age ranged from 10 to 14 years [(12.3±1.6) years], including 11 males and 14 females. The maxillary incisors with external root resorption before treatment were included in the resorption group (21 central incisors and 22 lateral incisors), and the maxillary incisors without external root resorption were used as the control group (26 central incisors and 21 lateral incisors). Cone-beam CT was taken before treatment, immediately after treatment and one year after treatment. At the one year follow-up 15 patients were collected (10 central incisors and 12 lateral incisors in the resorption group, while 16 central incisors and 12 lateral incisors in the control group). The root length and tooth volume of maxillary incisors were measured and analyzed before canine traction, after canine traction finished and at the one year follow-up. After the treatment of maxillary impacted canines, the root length and volume of the central and lateral incisors in both resorption group and control group were significantly less than that before treatment (<0.05). At the one year follow-up, the root length and volume of the incisors (central incisors in the resorption group and the central and lateral incisors in control group) were significantly less than those immediately after impacted canine traction (<0.05). During the canine traction, the difference of the volume change in lateral incisors between the resorption group [(17±6) mm] and the control group [(12±5) mm] was statistically significant (=2.51, <0.05). During the one year follow-up period, the difference between the changes of the root length in maxillary central incisors in the resorption group [(0.5±0.4) mm] and in the control group [(0.2±0.1) mm] was statistically significant (=2.35, <0.05). For maxillary incisors with external root resorption caused by impacted maxillary canines, the external root resorption could not stop immediately after the treatment of impacted canines. The root resorption in maxillary lateral incisors mainly occured during the traction process, while the root resorption in maxillary central incisors existed during the orthodontic treatment and in the follow-up period.
分析上颌尖牙阻生导致的切牙牙根外吸收情况，并探讨正畸治疗后切牙牙根外吸收的变化。选取2011年7月至2019年1月在南京医科大学附属口腔医院正畸科就诊的24例因上颌尖牙阻生导致切牙牙根外吸收的患者。年龄范围为10至14岁[（12.3±1.6）岁]，其中男性11例，女性14例。将治疗前有牙根外吸收的上颌切牙纳入吸收组（21颗中切牙和22颗侧切牙），将无牙根外吸收的上颌切牙作为对照组（26颗中切牙和21颗侧切牙）。在治疗前、治疗结束即刻及治疗后1年进行锥形束CT扫描。在1年随访时收集了15例患者（吸收组10颗中切牙和12颗侧切牙，对照组16颗中切牙和12颗侧切牙）。测量并分析上颌尖牙牵引前、牵引结束时及随访1年时上颌切牙的牙根长度和牙体体积。上颌阻生尖牙治疗后，吸收组和对照组中切牙及侧切牙的牙根长度和体积均显著小于治疗前（<0.05）。在1年随访时，切牙（吸收组中切牙及对照组中切牙和侧切牙）的牙根长度和体积显著小于上颌尖牙牵引结束即刻（<0.05）。在尖牙牵引过程中，吸收组[（17±6）mm]与对照组[（12±5）mm]侧切牙体积变化的差异具有统计学意义（=2.51，<0.05）。在1年随访期内，吸收组[（0.5±0.4）mm]与对照组[（0.2±0.1）mm]上颌中切牙牙根长度变化的差异具有统计学意义（=2.35，<0.05）。对于上颌尖牙阻生导致牙根外吸收的上颌切牙，在阻生尖牙治疗后牙根外吸收不会立即停止。上颌侧切牙的牙根吸收主要发生在牵引过程中，而上颌中切牙的牙根吸收在正畸治疗期间及随访期均存在。
