A Morphometric Study of the Mandibular Foramen in Dry Adult Human Mandibles in a Black Malawian Population

Abstract

The inferior alveolar nerve block (IANB) technique is a common technique performed on patients in dental surgery, placement of mandibular implants and other procedures involving the mandible. Precise identification of the mandibular foramen (MF) is essential for dental surgeons to accurately administer local anesthetics. Inaccurate localization of the mandibular foramen may result in IANB failure and injury to neurovascular tissues. Therefore, this study aimed at investigating the precise location of the MF from various anatomical land marks in dry adult human mandibles of Malawian population. The study was conducted on 29 dry adult human mandibles of unknown sex of Malawian origin from the Anatomy Division collection of human skeletons housed in the Biomedical Sciences Department, College of Medicine, University of Malawi. To determine the position of the mandibular foramen, distances from mandibular foramen to anterior margin, posterior margin, mandibular notch, gonial angle and mandibular base using a Vernier caliper were measured. The mean distance of the MF from posterior margin of mandibular ramus was 11.26±1.22 mm (right side) and 11.47±1.35 mm (left side), from the anterior margin 20.85±3.12 mm (right side) and 20.85±3.22 mm (left side) mandibles. The mean distance between mandibular notch (MN) and MF was 23.87±2.61 mm (right side) and 23.53 ± 2.65 mm (left side). The mean distance between mandibular base (MB) and MF for the right and left were 28.47 ± 2.90 mm and 27.85 ± 2.99 mm respectively. The inferior limit of the mandibular foramen was located at 24.69 ± 3.65 mm (right side) and 24.25 ± 2.77 mm (left side) to the angle (AG) of the mandible. The findings of this study show that the anterior margin mean distance from the MF for both right and left mandibles seem to be bilateral symmetrical suggesting the interpretation that the needle for IANB could be inserted at about 21 mm from the anterior margin to the MF in an adult of Malawian origin during surgery.