Prevalence and Variations in the Mandibular Canal assessed using Cone Beam Computed Tomography: A Retrospective Observational Study

Abstract

Introduction: Variations in the Mandibular Canal (MC) can be categorised based on shape (oval, round, or pear-shaped) and may include various accessory canals, such as bifid, trifid, or temporal crest canals. These variations are clinically significant because if, they are overlooked, they can lead to various complications. While both 2 Dimensional (2D) and 3D imaging modalities can evaluate these variations, Cone Beam Computed Tomography (CBCT) offers superior resolution, reduced radiation exposure, and a comprehensive 3D view. Aim: To analyse the prevalence and variations of the MC, as well as its diameter and length among the Indian population. Materials and Methods: A retrospective observational study was conducted in the Department of Oral Medicine and Radiology at Rajarajeswari Dental College and Hospital, Ramohalli Cross, Mysuru Road, Bengaluru, Karnataka, India over a period of six months from October 2023 to April 2024. Total of 190 CBCT images were randomly collected from the CBCT archives, spanning ages 16 to 75 years. The length and diameter of the MC were measured using CBCT tools. The prevalence of variations in the MC was determined according to the classification provided for bifid and trifid canals. The Chi-square test was employed to compare the anatomical variations of the MC based on age and gender, while an independent Student’s t-test was used to compare the mean length and mean diameter based on age groups and gender. Results: The mean age of the study population was 37.96±14.63 years. Among the 190 images, 105 (55.3%) belonged to males and 85 (44.7%) belonged to females. The frequency of bifid canals was comparatively higher than that of trifid and temporal crest canals, with incidence rates of 14.7%, 3.7%, and 5.3%, respectively, showing no significant association with age or gender. Females exhibited a bilateral reduction in vertical diameter (mean difference of 0.37 mm compared to males at 0.40 mm). The mean length of the MC was notably longer on the left-side among males (mean MC length on the left-side: 69.36 mm compared to the right-side: 67.64 mm). Conclusion: The present study highlights the importance of understanding variations in the MC. CBCT imaging enhances the comprehension of MC anatomy, facilitating accurate diagnostic and treatment strategies in dentistry and maxillofacial surgery.

Keywords

• bifid canal
• temporal crest canal
• trifid canal