Facial Muscles: Anatomy, Function, and Expression
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Source currency note: This guide reflects medical information reviewed in April 2025. Always confirm current guidance with your healthcare provider.
Quick Answer
Facial muscles are about 20 flat skeletal muscles that attach to the skull and insert into the skin. Their two major jobs are chewing and making facial expressions, and they also help you talk and protect your eyes. The facial nerve controls them, and sudden facial weakness or drooping needs prompt attention as a possible stroke. [3]
What the research says
Bell’s palsy is treated with corticosteroids. A meta-analysis of randomized trials in 317 people with Bell’s palsy (sudden one-sided facial weakness from cranial nerve VII) found that a single intravenous methylprednisolone dose led to more complete recovery at one month than oral prednisolone (log odds ratio 0.52), but there was no difference at three months (Abdu et al., European Archives of Oto-Rhino-Laryngology, 2024 [1]).
The smile muscles vary from person to person. A review of 75 studies on the zygomaticus major and minor muscles, which produce the smile, found meaningful differences in the number of muscle bellies, accessory structures, and insertion patterns, and proposed a five-type classification to help plan facial surgery and facial reanimation (Landfald & Olewnik, Journal of Clinical Medicine, 2025 [2]).
Functional groups of facial muscles
Facial muscles are grouped by where they sit on the face and what they do. They lie underneath the skin from the scalp down to the neck, around the facial openings, and they are usually paired, with one on the left and one on the right [3].
Muscles of mastication
These muscles do the work of chewing [3]:
Masseter: runs from the cheek to the side of the jaw and helps close the jaw.
Temporalis: a fan-shaped muscle on the side of the skull that helps close the jaw.
Medial pterygoid: a thick muscle that helps close the jaw.
Lateral pterygoid: a fan-shaped muscle that helps the jaw open.
Muscles of facial expression
These muscles lie just beneath the skin and produce the wide range of expressions people use to communicate. Muscles of expression are grouped by location [3]:
Group | Key muscles | Primary function |
Mouth (buccolabial) | Orbicularis oris, zygomaticus major and minor, buccinator, levator anguli oris, depressor anguli oris | Closing or pursing the lips, smiling, frowning, and holding the cheek against the teeth |
Eyes (orbital) | Orbicularis oculi, corrugator supercilii | Closing the eyelids and frowning |
Nose (nasal) | Nasalis, procerus | Flaring the nostrils and pulling the brows down |
Forehead and neck (epicranial) | Occipitofrontalis, platysma | Raising the eyebrows, wrinkling the forehead, and wrinkling the skin of the neck |
Ears (auricular) | Auricularis anterior, posterior, and superior | Moving the ears, which only some people can do |
How facial muscles function
Facial muscles work together in a coordinated way. The muscles of expression are supplied by the facial nerve, while the chewing muscles are supplied mainly by a different cranial nerve, the trigeminal nerve [3].
Communication and expression
Many facial muscles exist for non-verbal communication. By contracting and pulling on the skin, they create expressions that convey surprise, anger, happiness, and sadness. For example, the zygomaticus major pulls the corners of the mouth upward to produce a smile [3].
Protection and daily tasks
Eye protection: the orbicularis oculi closes the eyelids, which lets you blink and shield your eyes.
Speech and eating: muscles around the mouth, such as the orbicularis oris, help shape sounds and keep food and drink in your mouth.
Nose and brow: the nasalis flares the nostrils and the procerus pulls the brows downward.
Conditions affecting facial muscles
To work properly, facial muscles need clear signals from the brain through the facial nerve. When those signals are interrupted, facial movement can be impaired [3].
Common causes
Bell’s palsy: sudden, temporary weakness or paralysis on one side of the face, often from nerve inflammation.
Stroke: a medical emergency that can cause facial drooping if the brain’s control centers are damaged.
Traumatic injury: damage to the face or skull can injure the nerves or the muscle itself.
Infection, autoimmune disease, and head and neck cancer: each can damage the facial nerve or the muscles it controls.
Signs of muscle or nerve dysfunction
If facial muscles are not working properly, you may have trouble smiling, closing one eye, or keeping food and drink in your mouth. Drooling and a flat, expressionless look on one side of the face are also common signs of a nerve or muscle problem.
Maintaining facial health
Many facial muscle conditions need medical care, but a few habits help protect these muscles and the nerves that control them:
Act early: seek immediate medical care for sudden facial weakness. Prompt evaluation matters for conditions like Bell’s palsy and is essential if a stroke is possible.
Protect your face: wear appropriate headgear for sports and other high-risk activities to help prevent injuries to the facial nerves and muscles.
Treat infections promptly: infections can affect the facial nerve, so have them checked and managed early.
Conclusion
Facial muscles define our appearance and make our most basic interactions possible, from the strength it takes to chew food to the delicate movements of a smile. Understanding how they are organized and what can go wrong helps you protect them and recognize when something has changed [3].
If you notice sudden changes in your facial movement, or have trouble with expressions or chewing, see a healthcare professional right away to rule out serious causes. If the weakness comes with arm weakness or trouble speaking, call your local emergency number immediately.
Frequently Asked Questions
How many muscles are in the face?
The human face has about 20 flat skeletal muscles that control movements and expressions.
What is the main function of facial muscles?
Their two primary roles are making facial expressions and chewing (mastication).
Which nerve controls the facial muscles?
The facial nerve carries signals from the brain to the muscles of facial expression. The chewing muscles are supplied mainly by the trigeminal nerve.
What muscle allows you to smile?
Several muscles contribute to smiling, including the zygomaticus major and minor, the levator anguli oris, and the risorius.
What is the masseter muscle?
The masseter runs from the cheek to the side of the jaw. It helps close the jaw and is essential for chewing.
Can facial muscles move the ears?
Yes. The auricular muscles let some people move their ears, but not everyone has this ability.
What causes facial muscle paralysis?
Common causes include Bell’s palsy, stroke, traumatic injury, infection, autoimmune disease, and head and neck cancer.
How do facial muscles differ from other skeletal muscles?
Most skeletal muscles attach bone to bone, but facial muscles originate from bone or fascia and insert into the skin.
What muscle closes the eyes?
The orbicularis oculi, the circular muscle around the eye, closes the eyelids.
Why are facial muscles important for speech?
Muscles around the mouth, such as the orbicularis oris, shape the lips and mouth to produce different sounds.
Related Reading
Bell's Palsy: Symptoms, Causes, and Treatment explains sudden facial muscle weakness and how it is treated.
Blepharospasm: The Uncontrollable Eyelid Spasms That Can Force Your Eyes Shut — and How Treatment Keeps Them Open covers uncontrolled blinking caused by eyelid muscle spasms.
Botox Injections: Uses, Results, Side Effects and Aftercare describes how botulinum toxin injections relax facial muscles.
Understanding the Trigeminal Nerve explains the nerve that gives the face feeling and controls chewing.
References
Abdu SH, Alsubhi AH, Alzahrani A, et al. Comparison of oral versus intravenous steroid in the management of Bell’s palsy: a systematic review and meta-analysis of randomized clinical trials. European Archives of Oto-Rhino-Laryngology. 2024;281(3):1095-1104. PMID 37940744. https://doi.org/10.1007/s00405-023-08288-z
Landfald IC, Olewnik Ł. An interdisciplinary review of the zygomaticus muscles: anatomical variability, imaging modalities, and clinical implications. Journal of Clinical Medicine. 2025;14(12):4110. PMID 40565856. https://doi.org/10.3390/jcm14124110
Cleveland Clinic. Facial muscles. Cleveland Clinic. April 12, 2025. https://my.clevelandclinic.org/health/body/21672-facial-muscles
Medical disclaimer
This article was prepared for general information only and is not a substitute for professional medical advice.
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