Name
Pronunciation
(or-bik-yO-ler-is ok-U-lI)
Origin/Proximal Attachment
Fibers derived from other facial muscles (buccinator levators and depressors of lips and angles, zygomatic muscles) pass into lips; also some intrinsic muscle fibers make up orbicularis oris
Insertion/Distal Attachment
Several strata of muscle fibers from a sphincter-like muscle with fibers that decussate at the angles of the mouth.
Action/Relevance
Closes the lips and its deep fibers can press the lips against the teeth; also it protrudes the lipsand is important in speech.
Innervation
Buccal branch of the facial nerve.
Notes
Orbicularis oris is one of the muscles of the mouth. It arises from structures around the mouth:
* anterior surface of maxilla
* anterior surface of mandible
* modiolus at angle of mouth; at these points, orbicularis oris blends with fibres of buccinator
It inserts into the mucous membrane at the margin of the lips.
It is innervated by the buccal branch of the facial nerve (CN VII).
Orbicularis oris acts to:
* close the mouth
* purse the lips
* evert the lips
* modify the airflow during articulation