Antero-posterior location of the mental foramen in Nigerians.

The location of the mental foramen in the horizontal plane was studied in 604 oblique lateral radiographs of the mandible. The foramen was related to the apex of the second premolar root in 55.63 percent of the radiographs, while 26.99 percent occurred in the interdental space between the first and second premolars. Location between the roots of the second premolar and first molar was observed in 12.25 percent while relationship to the roots of the first molar was found in 3.30 percent. Location around the apex of the first premolar accounted for 1.66 percent. Only one foramen (0.17 percent) was found mesial to the first premolar. The radiographs of the right and left sides were available for 277 patients. The location of the mental foramen was asymmetrical in 12.3 percent of these patients, the right foramen being more frequently located posteriorly than the left foramen. The prevalence of asymmetrical location of the foramen was more frequent in females in whom it occurred in 53 percent.