The facial muscles are a group of striated

skeletal muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

s supplied by the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...

(cranial nerve VII) that, among other things, control facial expression. These muscles are also called mimetic muscles. They are only found in

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

s, although they derive from

neural crest Neural crest cells are a temporary group of cells unique to vertebrates that arise from the embryonic ectoderm germ layer, and in turn give rise to a diverse cell lineage—including melanocytes, craniofacial cartilage and bone, smooth muscle, per ...

cells found in all vertebrates. They are the only muscles that attach to the

dermis The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided i ...

Structure

The facial muscles are just under the skin ( subcutaneous) muscles that control facial expression. They generally originate from the surface of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

bone (rarely the fascia), and insert on the skin of the face. When they contract, the skin moves. These muscles also cause wrinkles at right angles to the muscles’ action line.

Nerve supply

The facial muscles are supplied by the facial nerve (cranial nerve VII), with each nerve serving one side of the face. In contrast, the nearby masticatory muscles are supplied by the mandibular nerve, a branch of the

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...

(cranial nerve V).

List of muscles

The facial muscles include: *

Occipitofrontalis muscle The occipitofrontalis muscle (epicranius muscle) is a muscle which covers parts of the skull. It consists of two parts or bellies: the occipital belly, near the occipital bone, and the frontal belly, near the frontal bone. It is supplied by th ...

Temporoparietalis muscle The temporoparietalis muscle is a distinct muscle of the head. It lies above the auricularis superior muscle. It lies just inferior to the epicranial aponeurosis of the occipitofrontalis muscle. The temporoparietalis muscle may be used in rec ...

Procerus muscle The procerus muscle (or pyramidalis nasi) is a small pyramidal slip of muscle deep to the superior orbital nerve, artery and vein. ''Procerus'' is Latin, meaning tall or extended. Structure The procerus muscle arises by tendinous fibers from t ...

Nasalis muscle The nasalis muscle is a sphincter-like muscle of the nose. It has a transverse part and an alar part. It compresses the nasal cartilages, and can "flare" the nostrils. Some people can use it to close the nostrils to prevent entry of water when un ...

Depressor septi nasi muscle The depressor septi nasi muscle (or depressor alae nasi muscle) is a muscle of the face. It connects the incisive fossa of the maxilla and the orbicularis oris muscle to the nasal septum of the nose. It draws the ala of the nose downwards, ...

Orbicularis oculi muscle The orbicularis oculi is a muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and borders of a short ...

Corrugator supercilii muscle The corrugator supercilii muscle is a small, narrow, pyramidal muscle close to the eye. It arises from the medial end of the superciliary arch, and inserts into the deep surface of the skin of the eyebrow. It draws the eyebrow downward and medi ...

Depressor supercilii muscle The depressor supercilii is an eye muscle of the human body. The nature of this muscle is in some dispute. Few printed anatomies include it (Netter, et al.) and many authorities consider it to be part of the orbicularis oculi muscle. On the ot ...

Auricular muscles The outer ear, external ear, or auris externa is the external part of the ear, which consists of the auricle (also pinna) and the ear canal. It gathers sound energy and focuses it on the eardrum (tympanic membrane). Structure Auricle Th ...

( anterior, superior and posterior) *

Orbicularis oris muscle In human anatomy, the orbicularis oris muscle is a complex of muscles in the lips that encircles the mouth. It is a sphincter, or circular muscle, but it is actually composed of four independent quadrants that interlace and give only an appearance ...

Depressor anguli oris muscle The depressor anguli oris muscle (triangularis muscle) is a facial muscle. It originates from the mandible and inserts into the angle of the mouth. It is associated with frowning, as it depresses the corner of the mouth. Structure The depres ...

Risorius The risorius muscle is a muscle of facial expression. It arises from the fascia over the parotid gland, and inserts into the angle of the mouth. It is supplied by the facial nerve (CN VII). It may be absent or asymmetrical in some people. It retr ...

Zygomaticus major muscle The zygomaticus major muscle is a muscle of the human body. It extends from each zygomatic arch ( cheekbone) to the corners of the mouth. It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly to allow ...

Zygomaticus minor muscle The zygomaticus minor muscle is a muscle of facial expression. It originates from the zygomatic bone, lateral to the rest of the levator labii superioris muscle, and inserts into the outer part of the upper lip. It draws the upper lip backward, u ...

Levator labii superioris The levator labii superioris (pl. ''levatores labii superioris'', also called quadratus labii superioris, pl. ''quadrati labii superioris'') is a muscle of the human body used in facial expression. It is a broad sheet, the origin of which extend ...

Levator labii superioris alaeque nasi muscle The levator labii superioris alaeque nasi muscle is, translated from Latin, the "lifter of both the upper lip and of the wing of the nose". It has the longest name of any muscle in an animal. The muscle is attached to the upper frontal process o ...

Depressor labii inferioris muscle The depressor labii inferioris (or quadratus labii inferioris) is a facial muscle. It helps to lower the bottom lip. Structure The depressor labii inferioris muscle arises from the lateral surface of the mandible. This is below the mental fora ...

Levator anguli oris The levator anguli oris (caninus) is a facial muscle of the mouth arising from the canine fossa, immediately below the infraorbital foramen. It elevates angle of mouth medially. Its fibers are inserted into the angle of the mouth, intermingli ...

Buccinator muscle The buccinator () is a thin quadrilateral muscle occupying the interval between the maxilla and the mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.Illustrated Anatomy of the Head ...

Mentalis The mentalis muscle is a paired central muscle of the lower lip, situated at the tip of the chin. It originates from the mentum of the mandible, and inserts into the soft tissue of the chin. It is sometimes referred to as the "pouting muscle" due ...

The

platysma The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effec ...

is supplied by the facial nerve. Although it is mostly in the neck and can be grouped with the neck muscles by location, it can be considered a muscle of facial expression due to its common nerve supply. The

stylohyoid muscle The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the hyoid ...

, stapedius and posterior belly of the

digastric muscle The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle bellie ...

are also supplied by the facial nerve, but are not considered muscles of facial expression.

Development

The facial muscles are derived from the second branchial/

pharyngeal arch The pharyngeal arches, also known as visceral arches'','' are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arche ...

. They, like the branchial arches, originally derive from neural crest cells. In humans, they typically begin forming around the eighth week of embryonic development.

Clinical significance

An inability to form facial expressions on one side of the face may be the first sign of damage to the nerve of these muscles. Damage to the facial nerve results in

facial paralysis Facial nerve paralysis is a common problem that involves the paralysis of any structures innervated by the facial nerve. The pathway of the facial nerve is long and relatively convoluted, so there are a number of causes that may result in facial ...

of the muscles of facial expression on the involved side. Paralysis is the loss of voluntary muscle action; the facial nerve has become damaged permanently or temporarily. This damage can occur with a

stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functionin ...

Bell palsy Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly improves over weeks. Symptoms can vary f ...

, or parotid salivary gland cancer (malignant neoplasm) because the facial nerve travels through the gland. The

parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...

can also be damaged permanently by surgery or temporarily by trauma. These situations of paralysis not only inhibit facial expression but also seriously impair the patient’s ability to speak, either permanently or temporarily.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 89

References

External links

ARTNATOMY: Anatomical Basis of Facial Expression Learning Tool
*
Facial muscles at PracticeAnatomy
{{Authority control Muscles of the head and neck

Muscles Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle ...