Department of Comprehensive Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
J Endod. 2020 Aug;46(8):1052-1058. doi: 10.1016/j.joen.2020.04.012. Epub 2020 May 11.
External cervical resorption (ECR) is a relatively uncommon type of external resorption; its treatment planning and prognosis are largely dependent on the clinician's subjective assessment. This study aimed to provide a volumetric assessment of ECR cases while correlating them to the Heithersay classification, treatment decision, and prognosis determined by 3 calibrated, independent evaluators.
A total of 168 ECR cases with corresponding periapical radiographs and cone-beam computed tomographic (CBCT) imaging were included in this study. An oral and maxillofacial radiologist calculated the volume occupied by the resorptive defects in root structures on CBCT imaging using Amira software (Thermo Scientific, Waltham, MA). Also, 3 board-certified endodontists evaluated anonymized and randomized periapical radiographs and corresponding CBCT images in separate sessions. Examiners were asked to provide a Heithersay classification, whether they would surgically repair the ECR lesion, and the expected prognosis of each case.
The percentage of radicular volume affected by ECR ranged from 0.5%-58% with a median of 12%. The volumetric quantification of ECR best correlated with classification and prognosis assigned by the independent examiners using CBCT evaluation. The greatest variation in agreement was observed on whether to surgically repair the ECR. However, examiners agreed more uniformly on not to treat when the resorptive port of entry was found on either the lingual or proximal surfaces of the tooth.
For the first time, the volumetric quantification of resorptive defects was calculated in vivo and correlated to the Heithersay classification and prognosis. Because the longevity of teeth affected with ECR depends on the integrity of the remaining root, the findings of this study provide important information to help clinicians decide on treatment planning and inform their patients of the expected prognosis. Future studies should focus on automating volumetric assessments of ECR to aid in unbiased chairside treatment planning decisions.
外部性牙颈部吸收（ECR）是一种相对罕见的外部吸收类型；其治疗计划和预后在很大程度上取决于临床医生的主观评估。本研究旨在通过 3 位经过校准的独立评估者对 ECR 病例进行分类、治疗决策和预后评估，对 ECR 病例进行体积评估。
本研究共纳入 168 例 ECR 病例，均有相应的根尖片和锥形束 CT（CBCT）影像学资料。口腔颌面放射科医生使用 Amira 软件（Thermo Scientific，Waltham，MA）计算 CBCT 影像中根结构内吸收缺陷的体积。此外，3 位经过认证的牙髓病专家在单独的会议上评估匿名和随机的根尖片和相应的 CBCT 图像。评估员被要求提供 Heithersay 分类、他们是否会手术修复 ECR 病变以及每个病例的预期预后。
ECR 引起的根体积百分比从 0.5%到 58%不等，中位数为 12%。使用 CBCT 评估，ECR 的体积量化与独立评估员分配的分类和预后相关性最好。在是否进行手术修复 ECR 方面，意见差异最大。然而，当发现 ECR 的吸收入口位于牙齿的舌侧或近中面时，评估员在不进行治疗的意见上更加一致。
这是首次在体内对吸收性缺陷进行体积量化，并与 Heithersay 分类和预后相关联。由于 ECR 受累牙的长期保留取决于剩余根的完整性，本研究的结果为临床医生提供了重要的信息，以帮助他们制定治疗计划，并向患者告知预期的预后。未来的研究应集中于 ECR 体积评估的自动化，以辅助无偏见的椅旁治疗计划决策。
