Marginal mandibular branch of the facial nerve

Marginal mandibular branch of the facial nerve
Plan of the facial and intermediate nerves and their communication with other nerves. (Labeled at center bottom, second from bottom, as "Mandibular".)
The nerves of the scalp, face, and side of neck.
Details
From	facial nerve
Identifiers
Latin	ramus marginalis mandibularis nervi facialis
Dorlands /Elsevier	r_02/12690722
TA	A14.2.01.113
FMA	53365
Anatomical terms of neuroanatomy

The marginal mandibular branch of the facial nerve passes forward beneath the platysma and depressor anguli oris, supplying the muscles of the lower lip and chin, and communicating with the mental branch of the inferior alveolar nerve.

Muscles innervated

The marginal mandibular branch innervates the following muscles:^[1]

• Depressor labii inferioris - lowers bottom lip down and laterally. Origin: Anterior part of oblique line of mandible. Insertion: Lower lip at midline, blends with muscle from opposite side.
• Depressor anguli oris (triangularis) - lowers the 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 - 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.

Additional images

• 
  Lateral head anatomy detail
• 
  Lateral head anatomy detail. Neonatal dissection.

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

External links

• Anatomy photo:23:06-0103 at the SUNY Downstate Medical Center - "Branches of Facial Nerve (CN VII)"
• lesson4 at The Anatomy Lesson by Wesley Norman (Georgetown University) (parotid3)
• cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (VII)
• http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-5.HTM