Wang Dongmiao, He Xiaotong, Wang Yanling, Li Zhongwu, Zhu Yumin, Sun Chao, Ye Jinhai, Jiang Hongbing, Cheng Jie
Department of Oral and Maxillofacial Surgery, Nanjing Medical University, 136, Hanzhong Road, Nanjing, 210029, China.
Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Nanjing, 210029, China.
Clin Oral Investig. 2017 May;21(4):1335-1342. doi: 10.1007/s00784-016-1888-y. Epub 2016 Jun 18.
The aim of the present study was to assess the incidence and risk factors of ERR in second molars with mesially and horizontally impacted mandibular third molars using cone beam computed tomography (CBCT) images from patients in a Chinese tertiary referral hospital.
A total number of 216 patients with 362 mesially and horizontally impacted mandibular third molars who were treated at our institution from 2014 to 2015 was retrospectively included. The ERR in second molars was identified on CBCT multiplanar images. The associations between incidence of ERR and multiple clinical parameters were statistically analyzed by Chi-square test. Moreover, the risk factors for ERR in second molars were further assessed by multivariate regression analysis.
The overall incidence of ERR in second molars was 20.17 % (73/362) as detected on CBCT images. The presence of ERR significantly associated with patients age and impaction depth of mandibular third molars. However, no significant relationship was found between ERR severity and impaction depth or ERR location. Multivariate regression analyses further revealed age over 35 years and impaction depth as important risk factors affecting the ERR incidence caused by mesial and horizontal impaction of mandibular third molar.
ERR in second molar resulted from mesially and horizontally impacted mandibular third molar is not very rare and can be reliably identified via CBCT scan.
Given the possibility of ERR associated with third molar impaction, the prophylactic removal of these impacted teeth could be considered especially for those patients with over 35 years and mesially and horizontally impacted teeth.
本研究旨在利用中国一家三级转诊医院患者的锥形束计算机断层扫描（CBCT）图像，评估下颌第三磨牙近中及水平阻生时第二磨牙牙根吸收（ERR）的发生率及危险因素。
回顾性纳入2014年至2015年在我院接受治疗的216例患者，共362颗下颌第三磨牙近中及水平阻生病例。通过CBCT多平面图像确定第二磨牙的ERR情况。采用卡方检验对ERR发生率与多个临床参数之间的关联进行统计学分析。此外，通过多因素回归分析进一步评估第二磨牙ERR的危险因素。
CBCT图像显示第二磨牙ERR的总体发生率为20.17%（73/362）。ERR的发生与患者年龄及下颌第三磨牙的阻生深度显著相关。然而，ERR严重程度与阻生深度或ERR位置之间未发现显著关系。多因素回归分析进一步显示，35岁以上年龄及阻生深度是影响下颌第三磨牙近中及水平阻生导致ERR发生率的重要危险因素。
下颌第三磨牙近中及水平阻生导致的第二磨牙ERR并不罕见，通过CBCT扫描可可靠识别。
鉴于第三磨牙阻生可能导致ERR，对于35岁以上且下颌第三磨牙近中及水平阻生的患者，可考虑预防性拔除这些阻生牙。
