The mental foramen: A cone beam CT study of the horizontal location, size and sexual dimorphism amongst living Jordanians.

Accurate information regarding the horizontal location and size of mental foramen (MF) has a well-known clinical importance. In addition, these variables have been reported to exhibit inter-population variation. The aims of the present study were to study the horizontal position and size of MF, as seen on cone beam CT (CBCT) images, and to assess sexual dimorphism in these variables. Total of 139 CBCT images of a random Jordanian sample (50 males, 89 females, average age = 43.5, SD = 13.0, range = 23-69 years) were included. The most frequent horizontal locations of MF were found to be: between the two lower premolars (50%), and in line with lower second premolar (40%). The average long diameter of MF was 3.08 mm, SD = 0.65 mm in males (n = 50, range = 1.5-4.8 mm) and 2.46 mm, SD = 0.58 mm in females (n = 89, range = 1.2-4.0 mm), and the difference was statistically significant. Very weak positive correlation was found between age and MF diameter in females (r = 0.161) and the correlation was approaching statistical significance (p-value = 0.066), while a weak negative correlation was found between these two variables in males (r = -0.276) and the correlation was statistically significant (p-value = 0.038). It could be inferred from the results of the present study that about 95% success rate for mental nerve block anesthesia is expected when the anesthetic solution is administered between the two premolars; however this needs to be tested experimentally. It appears that there is a tendency for an increase in MF size with age in females as opposed to a tendency for size reduction with age in males; this might suggest a role for sexual hormones in influencing MF size.