Unilateral Absence of Mental Foramen with Surgical Exploration in a Living Human Subject.

Murat Ulu,Fatih Gunhan,Elif Tarim Ertas,Huseyin Akcay,Meral Yircali Atici

doi:10.1155/2016/1971925

Abstract

The mental foramen (MF) is an important anatomic landmark of the mandible, in which the somatic afferent sensory nerve of the mandibular nerve emerges as mental nerve and blood vessels. The identification and actual location of MF are important in order to avoid sensory dysfunction or paresthesia due to mental nerve injury. In the literature there are some rare reports on the anatomical variations of the MF such as its location or presence of accessory foramina. The present report describes the absence of mental foramina on the left side of the mandible, as detected by cone-beam computed tomography before impacted tooth removal and observed directly during surgery.

Highlights

The mental foramen (MF) nerves divide into several branches to provide sensorial innervation of the angle of the mouth with its angular branch: the skin of the lower lip, oral mucosa, and gingiva up to the second premolar with its medial and lateral inferior labial branches and the skin of the mental region with its mental branch [1]
The identification and actual location of MF are important in order to avoid sensory dysfunction or paresthesia during any surgical procedures in this area, as well as achieving effective anesthesia [3, 5, 6]
Since the conventional radiographs such as periapical and panoramic films provide two-dimensional images of the mandible [2, 7], the MF may not be observed in some cases due to the superimposition of anatomic landmarks [5, 8], the pattern of trabecular bone [4], and the thinning of the mandible [5]

Summary

Introduction

The mental foramen (MF) nerves divide into several branches to provide sensorial innervation of the angle of the mouth with its angular branch: the skin of the lower lip, oral mucosa, and gingiva up to the second premolar with its medial and lateral inferior labial branches and the skin of the mental region with its mental branch [1]. MF is generally located in the area of premolar region as bilateral oval or round openings, race and ethnicity may affect its location [2]. Variations of the MF such as its location or presence of accessory foramina are reported in several articles but the absence of MF is extremely rare [5, 5]. We present here a case of unilateral absence of the mental foramen in a living patient detected on cone-beam computed tomography (CBCT) images and surgical exploration during lower impacted 2nd and 3rd molar extraction. According to our knowledge there is a very extremely rare case report in the literature which indicates absence of mental foramen with CBCT image and by surgical exploration

Case Report

Discussion