THE MARGINAL MANDIBULAR BRANCH OF THE FACIAL NERVE:
Netter Plate Number: 19A

The marginal mandibular branch of the facial nerve is often identified by its relationship to the branches of the facial artery as shown in this diagram. This nerve is identified by following the course of the facial artery and vein over the angle of the mandible, where the marginal mandibular nerve travels just superficial to these vessels. Lifting these vessels keeps the marginal mandibular nerve out of harm's way.

In the elderly, this relationship may be noted inferior to the inferior border of the mandible, as laxity of these tissues cause this nerve to swing downwards.

This nerve emerges from the anterior border of the parotid gland over the masseter muscle along the inferior angle of the mandible to innervate the depressor anguli oris m., depressor labii inferioris m. the mentalis m.

Branches of the facial nerve include: the 1) Temporal, 2) Zygomatic, 3) Buccal, 4) Marginal Mandibular and 5) Cervical branches.

This can be remembered by the mnemonic "Two Zebras Borrowed My Car".