Facial Muscle Anatomy & Function: A Visual Guide

The following facial muscle reference sheet is for audiences who wish to see facial muscles in action. While facial anatomy diagrams are key for learning location, structure, and inter-muscular relationships, their static form lacks motion context. If you need examples of muscles contracting on real people, explore the visuals below.

EPICRANIAL MUSCLE GROUP

The epicranial muscle group is made of occipitofrontalis (also known as frontalis and occipitalis) and temporoparietalis.

Occipitofrontalis Muscle: Frontal & Occipital Bellies

Frontal Belly

medial frontalis contraction

lateral frontalis contraction

FRONTALIS ACTION: The function of occipitofrontalis’ frontal belly (also known as the frontalis muscle) is to lift the brow and forehead area. Due to the frontal belly’s lack of bony attachments, frontalis contraction often causes slight hairline or upper scalp depression as well. Because the frontal belly can contract its medial and lateral segments in isolation, it is helpful to further break down frontalis movement by detailing its medial and lateral actions:

MEDIAL FRONTALIS ACTION: Lifts the inner brow and medial forehead area.
LATERAL FRONTALIS ACTION: Lifts the lateral brow and forehead areas with movement concentrated at the brow peaks.

FRONTALIS WRINKLES: Though often described as “horizontal,” frontalis-based wrinkles come in a variety of formations. They can indeed be flat, horizontal, and spanning across the entire forehead; however, they may also appear as gull wing-shaped lines, two segregated columns, medially-centered lines, aberrantly patterned, etc.

Occipital Belly

OCCIPITALIS ACTION: The function of occipitofrontalis’ occipital belly (also known as the occipitalis muscle) is to retract and tighten the scalp. This tightening effect is thought to counteract the scalp drag caused by frontalis.

Temporoparietalis

The 41st edition of Gray’s Anatomy describes the temporoparietalis as a “variably developed sheet of muscle that lies between the frontal parts of occipitofrontalis and the anterior and superior auricular muscles.” However, it does not describe the action of temporoparietalis. More information coming soon.

CIRCUMORBITAL & PALPEBRAL MUSCLE GROUP

The circumorbital and palpebral group is made up of orbicularis oculi, corrugator supercilii, and levator palpebrae superioris.

Orbicularis Oculi

orbital orbicularis oculi contraction

palpebral (preseptal) orbicularis oculi contraction

palpebral (pretarsal) orbicularis oculi contraction

Orbicularis oculi is a complex oval-shaped, sphincter-like muscle with varying functions. It is best to describe each subsection and function separately. For the scope of this guide, we will focus on the orbital and palpebral portions with quick mention of the lacrimal area. We will also further break down the palpebral area into its pretarsal and preseptal regions.

PALEPEBRAL PORTION

PRETARSAL ACTION: The function of the pretarsal portion of orbicularis oculi brings the innermost rings of the eyelid area (the lash line regions) toward the lacrimal caruncle. Pretarsal contraction contributes to involuntary blinking.
PRESEPTAL ACTION: The function of the preseptal portion of orbicularis oculi contributes to blinking and squinting. The upper portion of preseptal orbicularis oculi acts as a depressor; this part is likely to be most directly involved in forceful, or hard blinking and pressurized eye closure. The lower portion of preseptal orbicularis oculi acts as an elevator, bringing up the lower eyelid area to assist in squinting.

ORBITAL PORTION

ORBITAL ACTION: The function of the orbital portion is to contract the outermost rings of orbicularis oculi in a pinching-like motion. This pinching primarily affects the lateral portion of orbicularis oculi; however, the movement is strongest coming from the lower portion of the orbital section. In the Facial Action Coding System (FACS), this orbital contraction is called “cheek raiser” due to its widespread influence upon the upper cheek area.

Corrugator Supercilii

CORRUGATOR SUPERICILII ACTION: Corrugator supercilii’s function is to draw the brows toward the midline of the face, or, toward each other. As corrugator draws each brow medially, it does so at a downward angle. The degree to which corrugator draws the brows downward is variable from person to person with some individuals showcasing a strong downward pull and others showcasing little downward angling.

Though not always mentioned in anatomy textbooks, corrugator supercilii is composed of two heads:

transverse head: The transverse head is the larger of the two heads. Its dominant function is to draw the brows medially. You can think of the transverse head as the main brow squeezer.

oblique head: The oblique head is the smaller of the two heads. Its dominant function is to depress the medial brow area (similar to depressor supercilii).

It is possible that the downward angling variability of corrugator actions is due to either the angle of the transverse head (which runs along the orbital rim) and/or the interplay between the transverse and oblique heads.

Stay tuned! This guide is a work in progress. If you need more references now – see the FACS Cheat Sheet.

If you don’t know what FACS is…FACS, or the Facial Action Coding System, is an anatomically-derived, muscle-based system for classifying and describing facial motion in detail.