Evaluation of Relationship Between Mandibular Third Molars and Mandibular Canal: Comparison of Findings Obtained by Panoramic Radiography and Cone-Beam Computed Tomography

Abstract

Statement of the problem: It is important for oral surgeons to determine the precise location of mandibular third molar before extraction. The close relationship of mandibular canal and mandibular third molar is a risk factor for alveolar nerve damage.

Objective: The purpose of this study is to assess the relationship between mandibular canal and the mandibular third molar which has already been seen in close relationship on panoramic radiograph (PR) by the comparison of findings of the cone-beam computed tomography (CBCT) and the PR.

Materials & Methods: Close relationship between the mandibular third molar and mandibular canal was scanned in 180 patients by the PR. Images were also obtained by CBCT from patients among which a close-relationship was detected between mandibular canal and mandibular third molar.

Results: Close relationship was detected between mandibular third molar and mandibular canal on 26 of 180 PR and evaluated 46 mandibular third molars. In 41 cases, both the findings in PR and in CBCT images showed compliance with each other. As a result it was clearly seen that the mandibular third molars which were detected to be in close relationship on PR were mostly also in close relationship with mandibular canal on CBCT-images.

Conclusions: If the close relationship is not seen on the panoramic images then there is no need to get CBCT for extracting the mandibular third molars. By this way complication risks are eliminated with less radiation. However CBCT should be definitely used in cases which complete assessment cannot be made in no way due to artifacts such as superposition in PR.