An anatomical study of mental neurovascular bundle-implant relationships.

When five to six implants are used in a fixed reconstruction, it is desirable to place the most distal implant as close to the mental nerve as possible. This allows the cantilever of the fixed prosthesis to be extended posteriorly as much as is biomechanically feasible. Forty-seven mental nerve regions were dissected on cadavers to determine the exact relationship between the mental foramen, the inferior alveolar nerve, and its two terminal branches--the incisive and mental nerves. The most anterior position in which the mental nerve was encountered was 1 mm forward or mesial to the most anterior aspect of the mental foramen. Based upon this finding, it is likely that damage to the mental nerve can be avoided if the distal surface of the most posterior implant is 1 mm anterior to the anterior border of the mental foramen.