Location of the course of the mandibular canal, anterior loop and accessory mental foramen through cone-beam computed tomography.

Abstract

This study aimed at identifying the course of the mandibular canal, the presence of anterior loop and accessory mental foramen, as well as verifying the association between these variables through the analysis of cone beam computed tomography (CBCT) exams. CBCT images were analyzed to identify the type of mandibular canal path, classified into three types: (I) catenary; (II) progressive descending; and (III) straight. In addition, the presence of anterior loop and accessory mental foramen was analyzed. The variables were summarized by measures of absolute frequency, relative, mean and standard deviation. The Chi square and Fisher's exact tests were used in the comparative analysis of the frequency distribution. The level of significance was 5%. The most frequent mandibular canal course was straight type (74.4%), followed by catenary (19.4%) and finally the progressive descending (6.2%). It was observed a prevalence of 10.2% for anterior loop and 7.9% for accessory mental foramen. There was no association between the presence of anterior loop (P = 0.798) and accessory mental foramen (P 0.480) with the mandibular canal course pattern, as well as no association between the anterior loop and the presence of the accessory mental foramen (P = 0.407). The CBCT analysis is the best methodology for the investigation and localization of mandibular anatomical variations, which provides a good image quality of the bone tissue and details of the anatomical structures, reducing the risk of injury to the lower alveolar vascular-nervous bundle and, consequently, cause paralysis and hemorrhage in the anterior region of the mandible and adjacent structures.