Incidence, Location, and Sizes of the Accessory Mental Foramina Assessed by Cone-Beam Computed Tomography

Aim: The aim of this study was to assess the incidence, location, and sizes of the accessory mental foramina using cone-beam computed tomography (CBCT). Materials and methods: The CBCT records of 1400 Caucasian race patients were evaluated for accessory mental foramina (AMF). Their presence and location in relation to the mental foramen (MF) were assessed using axial, panoramic, and cross-sectional 2-dimensional CBCT images. The long and short axes diameters of the AMF were also measured. Results: Accessory mental foramina were observed in 3.86% of the patients: up to two foramina on one side, unilaterally presented in 94.4% of cases with AMF. Their location regarding the MF was distally and inferiorly in 62.9%. In 35.5% of cases with AMF, the foramen was situated above the level of MF and therefore needs special attention before surgery. The mean inner long and short axis diameters were 1.5 mm (SD: 0.4 mm) and 1.2 mm (SD: 0.3 mm) respectively. The measurements ranged from 0.7 - 2.5 mm for the long axis and 0.7 - 2 mm for the short axis. Conclusion: Demonstration of AMF using CBCT can improve the surgery treatment planning in the anterior part of the mandible and thus helps to avoid unwanted neurovascular damage and possible malpractice litigations.