Estudo das posições dos terceiros molares inferiores em relação ao canal mandibular: uma comparação entre radiografias panorâmicas e tomografias computadorizadas de feixe-cônico

Abstract

Study of the positions of mandibular third molars in relation to the mandibular canal: A comparison between panoramic radiography and cone beam computed tomography The aim of this study was to evaluate the positions of mandibular third molars in relation to mandibular canal in cone-beam computed tomography (CBCT) and digital panoramic radiographs (PRs). The study involved 230 digital PRs of patients who had at least one mandibular third molar, and necessarily had a CBCT scan of these teeth. These exams were collected from the FOUFMG Radiology Service image files. The CBCT images were compared with the PRs images in relation to: proximity to the mandibular canal and presence/absence of dilaceration. The position of the mandibular canal in relation to the tooth and the position of the middle/apical thirds of the tooth in relation to the alveolar bone ridge were evaluated in CBCT. A crosssectional study was conducted with a quantitative approach. The images were analyzed by a calibrated professional. There was an agreement of 71.8% regarding the presence of contact with the mandibular canal and 62.4% with the absence of dilaceration. In relation to the mandibular canals, 38.5% were located below the roots of the mandibular third molars, 27.9% for vestibular, 27.4% for lingual and 6.2% were between the roots. In relation to the position of the tooth, 58.2% were close to the lingual cortical bone, followed by 29.1% in the center of the ridge and finally by 12.6% close to the buccal cortical bone. Despite the high concordance between the two exams, CBCT reveals important information such as the position of the mandibular canal in relation to the tooth and the position of the tooth in relation to the alveolar bone ridge. Key words: Third molar. Cone Bean Computed Tomography. Mandibular Canal.