Mental Foramen Size, Position and Symmetry in a Multi-Ethnic, Urban Black Population: Radiographic Evidence.

Objectives: To determine the approximate location, shape and dimensions of the mental foramen in African subjects using panoramic radiographs.

Material and methods: This study analysed 320 orthopantomograms of subjects from two centres. The analysis was done using the radiographic software tools (SIDEXIS, Bensheim, Germany) which allowed for determination of the position, shape and dimensions of the foramen. Furthermore, the right and left mental foramina were compared to ascertain both shape and positional symmetry.

Results: Most of the foramina analysed were horizontally positioned between the mandibular first and second premolars (65.9%) and vertically positioned greater than 2 mm below the apex of the second mandibular premolars. The average vertical dimension and horizontal dimension of the foramen is 2.87 (SD 1) mm and 3.56 (SD 1.23) mm respectively with 55.2% of the foramen analysed being ovoid in shape. Asymmetrical mental foramina were seen in 164 subjects (51.3%) while 156 subjects had symmetrical mental foramina (48.7%).

Conclusions: The mental foramen is most commonly located between the mandibular premolars, greater than 2 mm below the apex of the second mandibular premolars. They are usually ovoid in shape with an almost equal distribution of asymmetry and symmetry.