Relationship of the Presence of Lingual Concavity and Mandibular Canal Location: A Retrospective Two-Center Study

Aim: To evaluate the possible relationship between the position of the mandibular canal (MC) on digital panoramic images (PI) and the presence of a lingual concavity (LC) on Cone-Beam Computed Tomography (CBCT) scans in two different populations.Materials and methods: In this retrospective study, the digital archives of a private imaging center in Turkey and at The Academic Center for Dentistry Amsterdam (ACTA) in Netherlands patients who had both panoramic and CBCT images, taken between January 2016 and June 2016 due to various indications. A total of 248 patients were assessed. MC position was defined on digital panoramic radiographs; the presence of LC was assessed on CBCT images. In all statistical methods, p value <0.05 was considered statistically significant. The Mc Nemar test and the receiver operating characteristics (ROC) curve analysis (AZ), were performed for data analysis.Results: Considering all patients, the presence of LC was 28% and 31% for the left and right premolar regions and 75% and 77% for the left and right molar regions, respectively. There was no significant difference between right and left sides and between the Turkish and Dutch populations with respect to the presence of LC. Considering all patients, the presence of a LC was higher in the molar region than in the premolar region for both right and left sides with a statistical significance (p<0.001). Conclusions: The higher percentages of LC in the molar region in both populations suggests that a preoperative local CBCT assessment is justified specifically before implant placement in the mandibular molar region. The location of the MC on the PI was not a very strong indication of the presence of a LC.