Radiographic and Cadaveric Determination of the Mental Foramen Position in Adults in Ghana

Abstract

Background: The mental foramen which transmits mental nerve is an important anatomical landmark in mental nerve block and other invasive procedures in the oral and maxillofacial region. Variations in the position of the mental foramen exist between populations and even among inhabitants of common geographic environment. There have been reports of alteration in sensations following dental procedures such as implant placement and orthognathic surgeries probably due to inaccurate localization of the mental foramen. Despite its clinical significance, little is known about its position in adults in Ghana. Aim: This study investigated the anatomy of the mental foramen on the mandibles of adults in Ghana using radiographs and cadaveric subjects. Methodology: Twenty-four (24) dissected cadaver mandibles and four hundred and five (405) archived dental panoramic radiographs of individuals with full skeletal development were examined. The horizontal position of the mental foramen was determined in relation to the mandibular teeth using a rule and the dimensional tool of the proprietary radiographic software (CS software version 7) respectively. Other anthropometric characteristics of the mental foramen such as the number of foramina present, shape, size and orientation of its opening were examined. Data obtained were stored in excel and analyzed using S.P.S.S version 22. Results: The mental foramen was found to be most prevalent at the apex of the second mandibular premolar in both radiographs (52.1%) and cadavers (50%). The position between the second mandibular premolar and first molar was the second most common (radiographs=28.4%, cadavers=39.6%). In about four-fifth of the mandibles, the mental foramen position was bilaterally symmetrical in both subject groups. Bilateral foramina type was most common in both radiographic (98.77%) and cadaveric (100%) subjects. A unilateral foramen (0.25%) and unilateral accessory mental foramina (0.99%) were noted in the rest of the radiographs examined. From the cadavers, the mental foramen was predominantly oval, with mean size of 3.17mm horizontally and 2.47mm vertically and its opening, postero-superiorly directed. Conclusion: This study, being the first on the mental foramen in Ghana, has established that the MF is most commonly positioned at the apex of the second lower premolar in adults in Ghana.