Quantitative assessment of the relationship of mandibular canal with impacted third molars: A retrospective analysis of cone beam computed tomographic evaluation in Dharwad population, India

Impacted third molars tend to pose certain problems varying from pain, repeated pericoronitis, bone loss with adjacent teeth, etc. The surgical removal of impacted teeth requires appropriate planning to avoid complications. Cone beam computed tomography (CBCT) is an important radiographic tool that facilitates appropriate treatment planning. This retrospective analysis of the existing orthopantomographs (OPG) and CBCT images of third molars was conducted to assess the topographic relationship between impacted mandibular third molar and the inferior alveolar nerve (IAN) canal. In this study, 124 OPGs and CBCT images were used to assess the type of impactions and evaluate the relationship of impacted teeth with the IAN. Mesioangular impaction was the most commonly observed type of impaction followed by vertical, horizontal, and distoangular impactions. The most commonly observed relationship was mandibular canal running apically or buccally with respect to the impacted tooth but without being in contact with it. The classification utilizing the topographic relationship of the impacted mandibular third molar with the IAN canal gives a clear position of the IAN to the impacted teeth. The use of digital volume tomography (DVT) for radiographic assessment reveals the relationship in axial, coronal, and sagittal dimensions, which facilitates appropriate treatment planning to avoid post-operative complications.