Dictionary.net

Is the outer orifice of the inferior dental canal. It is situate on the outer surface of the lower jaw-bone, opposite the second incisor, or the canine tooth, and gives passage to the vessels and nerves.

Foramen of lower jaw for mental nerve and vessels.

A f. in the inferior maxilla external to the incisor fossa, midway between the upper and lower border of the bone, and under the interval between the two bicuspid teeth. It transmits the mental nerve and vessels.