Evaluation of the distance between the root apices of mandibular first and second premolars and first molars and the mental foramen using cone-beam computed tomography

The mental foramen is a prominent anatomical landmark of the mandible. The mental nerve might be damaged in several procedures, such as periapical surgeries, extraction of impacted teeth, enucleation of cysts and tumors and endodontic surgeries, leading to paresthesia and anesthesia. The aim of the present study was to determine the position of the mental foramen using cone-beam computed tomography (CBCT) images.
In this cross-sectional descriptive/observational study, 100 CBCT images (belonging to 50 males and 50 females) in cross-sectional and tangential views were selected from the archives of the Department of Radiology, Isfahan Faculty of Dentistry, in order to determine the location of the mental foramen and determine its distance from the root apices of the first and second premolars and mesial root of first molar, and also from the lower boarder of the mandible. Data was analyzed with SPSS, using t-test and chi-squared test (α=0.05).
In 59.6% of the cases the mental foramen was located between the first and second premolars, and in 38.4% of the cases it was located between the second premolar and the mesial root of the first molar. The mean distances between the mental foramen and root apices of the first and second premolars and the first molar were 7.85, 6.27 7.99 mm, respectively, with a mean distance of 11.35 mm from the inferior border of the mandible.
The most common position for the mental foramen in this Iranian sample was between the first and second premolars, followed by between the second premolar and the first molar.