Clinical significance of the anterior loop of the mental nerve: anatomical dissection of a cadaver population at the University of the Witwatersrand

Abstract

INTRODUCTION: The anterior loop (AL) of the mental nerve is an anatomical structure that should be considered when placing dental implants in the region of the mental foramen. This study aimed to evaluate the presence and dimensions of the AL using anatomical dissection of cadaver specimens. METHODS: 20 cadaver specimens were dissected bilaterally yielding 40 sides. The position of the mental foramen was recorded in relation to the lower border of the mandible as well as the adjacent teeth. Additionally, the mental foramen was probed before accessing the AL in order to determine the relationship between probing and actual AL length. The AL of the mental nerve was identified through anatomical dissection and measured. RESULTS: The mental foramen was most commonly located between the 1st and 2nd premolars (45%) followed by the apex of the 2nd premolar (42.5%). The mental foramen ranged from 10,16mm to 16,47mm from the lower border of the mandible (Mean 13,15mm; SD 1,61mm). An AL was found in 22 sides (55%) with a range of 0,52mm to 4,29mm (Mean 1,18mm; SD 1,35mm). Probing versus actual AL length revealed a weak negative correlation between AL length and probe depth. CONCLUSIONS: The study has shown that clinically significant AL lengths can be present and implant planning must therefore account for these AL.