The relationship of the inferior alveolar nerve canal with the roots of impacted mandibular third molars in a group of the South Indian population

Abstract

Aim/Objective: The aim of this study was to evaluate the topographic relationship between the inferior alveolar nerve canal (IANC) and the roots of impacted mandibular third molars. Materials and Methods: The study conducted at the Department of Oral Medicine and Radiology, Maratha Mandals NG Halgekar College of Dental Sciences and Research Center, Belgaum, Karnataka, India. A total of 100 patients (54 female and 46 male) visiting the outpatient department between the age group of 18 and 50 years, with a mean age of 24 years, were selected. Before starting the study, ethical clearance was taken from the ethical committee and informed consent was taken from each patient who underwent radiographic examination. The study included only those patients who had a full set of dentition in their mouth visible clinically. No cases with history of extraction or invisible (agenesis) cases were included in our study. Pre-operative orthopantomograms (OPGs) were examined and the proximity of the IANC to the roots of impacted mandibular third molars was categorized into the following groups: Superimposition, adjacent, perforation, grooving, notching or none. The categories notching, grooving and perforation were regrouped together and called the true relationship between the IANC and the root apices. The type of impaction, age and sex of the patient were also noted. Results: The greater number of impacted third molars was of mesioangular position and accounted for 98 (49%) of the total sample. Only six (3%) third molars were classified under the classification as aberrant. The prevalence of the impacted third molar was more common in the 18-30-year-old age group, with the mesioangular (98 [49%]) type of impaction being the most common type. The position of the IANC showed that 50 (25%) teeth were of superimposition, 41 (20.5%) teeth were of adjacent, 49 (24.5%) teeth were of grooving, 17 (8.5%) teeth were of notching and 30 (15%) teeth were of perforating categories in relation to the IANC. The remaining 13 (6.5%) teeth could not be placed under any of these categories and, therefore, were placed in the category none. The relationship between the IANC and the angular position of the mandibular third molars was found to be more common in mesioangular impactions (49%) than in any other type of impaction. Six impacted molars were in aberrant impaction (3%), and these fell into the superimposition category. Conclusion: The position of the IANC in relation to the roots of the impacted third molars varied according to the patient's age.