Depressor labii inferioris muscle

Depressor labii
Muscles of the head, face, and neck.
Latin	musculus depressor labii inferioris
Gray's	subject #108 383
Origin	oblique line of the mandible, between the symphysis and the mental foramen
Insertion	integument of the lower lip, Orbicularis oris fibers, its fellow of the opposite side
Artery
Nerve	facial nerve
Actions	{{{Action}}}

The depressor labii inferioris (or quadratus labii inferioris) is a facial muscle that helps lower the bottom lip.

Structure

This muscle arises from the oblique line of the mandible, and inserts on the skin of the lower lip, blending in with the orbicularis oris muscle. At its origin, depressor labii is continuous with the fibers of the platysma muscle. Much yellow fat is intermingled with the fibers of this muscle.

Innervation

The depressor labii inferioris is innervated by the mandibular division of the facial nerve.

Actions

This muscle helps to depress the lower lip.

See also

• Facial muscles
• Depressor anguli oris

Additional images

• 

  Mandible. Outer surface. Side view.

External links

• LUC dli
• -677773235 at GPnotebook
• Depressor+labii+inferioris+muscle at eMedicine Dictionary

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.