Anatomical Position of Lower Third Molar in Relation to Mandibular Canal on Cone-Beam Computed Tomography Images in A Tertiary Care Hospital: A Descriptive Cross-sectional Study

INTRODUCTION: The positional relationship between the mandibular canal with impacted mandibular third molar is the main factor of inferior alveolar nerve injury. The purpose of this study was to classify the anatomical three-dimensional relationship between the proximity of impacted mandibular third molars to the inferior alveolar canal. METHODS: The descriptive cross-sectional study was conducted in the Department of Oral and Maxillofacial Surgery of a tertiary care hospital from July 2020 to August 2020 after obtaining ethical approval from the institutional review committee (Reference number 2506202001). Cone-beam computed tomography images of 200 patients' mandibular third molars were used. A convenient sampling method was used. Data were analyzed using Statistical package for the Social Sciences. RESULTS: Mandibular canal relative to the roots of the mandibular third molar was observed on the apical side in 104 (52.0%) and 173 (86.5%) third molars had direct contact with the mandibular canal. About 36 (97.3%) lingually placed mandibular third molars had contact with the mandibular canal. CONCLUSIONS: The findings of the study conclude that most of the mandibular third molars situated lingually had a higher occurrence of mandibular nerve involvement. The anatomic structures of the mandibular third molar and the mandibular canal may be helpful to draw upon the adequate surgical plan to avoid or reduce nerve involvement.