Position of the mental foramen in a North American, white population.

Knowledge of the position of the mental foramen is important both when administering regional anesthesia and performing periapical surgery in the mandible. Although it is often possible to identify the mental foramen by palpation and radiographically, knowing the normal range of possible locations is essential. Standard anatomic texts have data collected from dried skulls, but often of unknown origin or from an ethnic group that does not represent the North American population. This study identified the position of the mental foramen in a more representative sample of the North American population. Ethnic and gender differences were also investigated and the symmetry of location within individuals analyzed. Regional dissections of 105 human cadavers were carried out to identify the normal range of position of the mental foramen. The vertical and horizontal position was recorded with the two adjacent teeth used as references. If the two adjacent teeth were not present the foramen was not included in the study. The results indicated that the mental foramen was, on average, between the premolars, therefore not statistically different from previous studies. However, there appears to be a greater range than generally reported, which is of considerable clinical significance. Examples of dissections of unusually positioned mental foramina are given.