A CBCT Based Evaluation of The Varying Location of Mandibular Canal and Mental Foramen: An Original Research Study

Abstract

Background and Aim: Iatrogenic injuries to inferior alveolar nerve (IAN) are a well known complication of implant placement, osteotomies and other surgical procedures. This study was at attempted to determine the most common position of the mental foramen and to estimate difference in position of mental foramen, occurrence of anterior loop and to evaluate the variation in the location of mandibular canal using cone-beam computed tomography (CBCT) radiographs. Materials & Methods: A total of 205 north Indian subjects were selected during a period of two years. Formerly exposed CBCT images of the selected subjects were studied by ‘iCAT Vision’ and ‘Anatomage’ Software. Measurements from the mandibular canal to the root apices of the first premolar, second premolar, first molar and second molar were obtained. Likewise the distance from the inferior alveolar canal to the buccal cortical plate (BCP) and lingual cortical plates (LCP) were also studied. The estimation of the horizontal and vertical positioning of mental foramen on the CBCT images was also done on both sides. Other inter-related dimensional parameters were also studied comprehensively. The incidence of Anterior Loop (AL) was also assessed and comparisons were done among both sides of the jaw and gender. Statistical Analysis and Results: A total of 205 subjects comprising of 108 (52.7%) males and 97 (47.3%) female participated in the study. The Unpaired t-test showed a statistically significant difference among males and females in the measurements of IAC. Among males Linear, Perpendicular and Anterior loop pattern was seen in 64 (59.3%), 34 (31.4%) and 10 (9.3%) subjects respectively. Among males prevalence of right sided anterior loop (Mental Foramen) was 10 (30.3%), left sided anterior loop was 10 (30.3%). The Unpaired t-test showed a statistically non-significant difference among males and females. (p>0.5) Anterior loop was seen on 17 (51.5%) occasions on the right side and 16 (48.5%) occasions on the left side. The Pearson’s Chi-square test showed a statistically non-significant difference among the genders on the right side. Conclusion: The most common configurations alveolar canal was the linear pattern followed by perpendicular pattern. Most frequent location of mental foramen was in continuity with second premolar in both the left and right sides as well as in both the genders. The anterior loop was the least common pattern of inferior alveolar canal.