Location of mental foramen based on soft- and hard-tissue landmarks in a chinese population

The purpose of the present study was to determine the location of the mental foramen (MF) based on soft- and hard-tissue landmarks, to facilitate prediction of the location of this structure during facial and dental surgery. Forty-two hemispheres of 21 adult cadavers (16 men and 5 women; aged 30-75 years) were dissected to expose the MF. The locations of the MFs were evaluated with direct and photographic measurements. Most of the MFs presented a single foramen (95%), except for only 2 cases with double foramina (5%). The MFs localized 23.38 +/- 2.00 mm inferior and 3.55 +/- 1.70 mm medial to the cheilion in the front view while 23.59 +/- 2.11 mm inferior and 7.19 +/- 3.03 mm posterior to the cheilion in the lateral view. Based on the hard-tissue landmarks, we found that most of the MFs localized inferior the second premolar in most of the cases (73.8%), and the MFs localized 23.34 +/- 2.39 mm below the cusp tip of the second premolar, 16.56 +/- 2.53 mm below the inferior alveoli, and 15.56 +/- 1.74 mm superior the bottom of the mandible. The position of the MF varied from 8.7 degrees medial to 15.5 degrees posterior in the vertical angle with the change of surgical body position from supine to lay-side position. Our results may provide a more detailed information to predict the location of the MFs.