Nunes Willy James Porto, Vieira Aline Lisboa, de Abreu Guimarães Letícia Drumond, de Alcântara Carlos Eduardo Pinto, Verner Francielle Silvestre, de Carvalho Matheus Furtado
Department of Clinical Dentistry, Federal University of Juiz de Fora, Brazil.
Department of Stomatology, University of São Paulo, Brazil.
Imaging Sci Dent. 2021 Mar;51(1):9-16. doi: 10.5624/isd.20200095. Epub 2021 Jan 28.
The purpose of this study was to analyze the reliability of 7 panoramic radiographic signs for predicting proximity of the root apices of mandibular third molars to the mandibular canal using cone-beam computed tomography and to correlate these findings with the Pell and Gregory and the Winter classification systems.
An observational, cross-sectional, descriptive study was conducted on 74 patients with bilateral impacted mandibular third molars. Four panoramic radiographic signs were observed in the tooth root (darkening, deflection, and narrowing of the root apices, and bifid apices), and another 3 in the mandibular canal (diversion, narrowing, and interruption of the mandibular canal). Cone-beam computed tomography images were analyzed to identify disruption and diversion of the mandibular canal and root deflection.
Binary logistic regression showed that only 4 of the 7 panoramic radiographic signs were able to predict proximity of the root apices of the mandibular third molars to the mandibular canal: darkening of the root, deflection of the root, narrowing of the root, and interruption of the mandibular canal (<0.05).
Darkening, deflection, and narrowing of the root, in tandem with the interruption of the mandibular canal on panoramic radiographs, indicate that cone-beam computed tomography should be performed when planning the extraction of impacted mandibular third molars. Proximity between mandibular third molars and the mandibular canal is correlated with the Winter classification.
本研究旨在利用锥形束计算机断层扫描分析7种全景放射学征象预测下颌第三磨牙根尖与下颌管接近程度的可靠性，并将这些结果与佩尔和格雷戈里分类系统以及温特分类系统相关联。
对74例双侧下颌阻生第三磨牙患者进行了一项观察性、横断面、描述性研究。在牙根观察到4种全景放射学征象（根尖变黑、弯曲、变窄和双尖），在下颌管观察到另外3种征象（下颌管移位、变窄和中断）。分析锥形束计算机断层扫描图像以确定下颌管的破坏和移位以及牙根弯曲情况。
二元逻辑回归显示，7种全景放射学征象中只有4种能够预测下颌第三磨牙根尖与下颌管的接近程度：牙根变黑、牙根弯曲、牙根变窄和下颌管中断（<0.05）。
全景片上牙根变黑、弯曲和变窄，以及下颌管中断，表明在计划拔除下颌阻生第三磨牙时应进行锥形束计算机断层扫描。下颌第三磨牙与下颌管的接近程度与温特分类相关。
