On arriving at the incisor teeth, it turns back to communicate with the mental foramen, giving off a small canal known as the mandibular incisive canal, which run to the cavities containing the incisor teeth.

The mandibular canal often runs close to the apices of the third molar tooth, and the inferior alveolar nerve can become damaged during removal of this tooth, causing sensory disturbance in the distribution of the nerve.

This is sometimes the case for the second or first molar teeth, and care must be taken during removal or root canal treatment in such cases to prevent nerve injury or extrusion of root canal filling materials.

Other variants include a bifid canal with a branch (~41%):[3] following the course of the main mandibular canal before re-joining it (forward or buccolingual type); terminating at the apex of a tooth, usually the molar teeth (dental type); opening as an accessory mental foramen.

[5][6] This article incorporates text in the public domain from page 173 of the 20th edition of Gray's Anatomy (1918)