The marginal mandibular branch of facial nerve passes forward beneath the Platysma and Triangularis, supplying the muscles of the lower lip

Lower lip

The lower lip covers the anterior body of the mandible.It is lowered by the Depressor labii inferioris muscle....

 and chin

Chin

In the human anatomy, the chin is the lowermost part of the face.It is formed by the lower front of the mandible.People show a wide variety of chin structures. See Cleft chin....

, and communicating with the mental branch of the inferior alveolar nerve

Inferior alveolar nerve

The inferior alveolar nerve is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve .-Path:...

.

Muscles innervated

Depressor labii inferioris- lowers bottom lip down and laterally. Origin: Anterior part of oblique line of mandible. Insertion: Lower lip at midline, blends with musle from opposite side.

Depressor anguli oris (Triangularis) - lowers corner of the mouth down and laterally. Origin: Oblique line of mandible below canine, premolar, and first molar teeth. Insertion: Skin at the corner of mouth and blending with orbicularis oris.

Mentalis

Mentalis

The Mentalis is a paired central muscle of the lower lip, situated at the tip of the chin. It raises and pushes up the lower lip, causing wrinkling of the chin, as in doubt or displeasure...

- raises and protrudes lower lip as it wrinkles skin on chin. Origin: Mandible inferior to incisor teeth. Insertion: Skin of chin

Clinical significance

The marginal mandibular nerve may be injured during surgery in the neck region, especially during excision of the submandibular salivary gland or during neck dissections.

External links

- "Branches of Facial Nerve (CN VII)"

• http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-5.HTM