Triangularis

Depressor anguli oris
Scheme showing arrangement of fibers of Orbicularis oris (triangularis labeled at bottom right).
Muscles of the head, face, and neck (labeled as triangularis near chin).
Details
Origin	Tubercle of mandible
Insertion	Modiolus of mouth
Artery	Facial artery
Nerve	Mandibular branch of facial nerve
Actions	Depresses angle of mouth
Identifiers
Latin	Musculus depressor anguli oris
TA	A04.1.03.026
FMA	46828
Anatomical terms of muscle []

The depressor anguli oris (triangularis) is a facial muscle associated with frowning. It originates from the mandible and inserts into the angle of the mouth.

The muscle is innervated by the marginal mandibular branch of the facial nerve and receives its blood supply from the facial artery.

The depressor anguli oris arises from the line of the mandible, whence its fibres converge, to be inserted, by a narrow fasciculus, into the angle of the mouth. At its origin it is continuous with the platysma, and at its insertion with the orbicularis oris and risorius; some of its fibers are directly continuous with those of the caninus, and others are occasionally found crossing from the muscle of one side to that of the other; these latter fibers constitute the transversus menti.

The depressor anguli oris is a muscle of facial expression. The muscle depresses the corner of the mouth which is associated with frowning

Position of depressor anguli oris muscle

Mandible, outer surface, side view

The arteries of the face and scalp

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