The Face

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Blood supply of the head & neck | Main Anatomy Index | The temporal region

Last updated 30 March 2006

The Muscles of Facial Expression

These lie in the subcutaneous tissue and are attached to the skin of the face.
They enable us to move our skin and change our facial expression. They produce their effects by pulling on the skin but do not move the facial skeleton.
These muscles surround the facial orifices and act as sphincters and dilators.

All facial muscles receive their innervation from the branches of the facial nerve (CN VII)-temporal, zygomatic, buccal, marginal mandibular, cervical.

Muscles of the Forehead

The Frontalis Muscle (p. 656)

The frontalis muscle is part of the scalp muscle called the occipitalfrontalis.
The frontalis elevates the forehead, giving the face a surprised look, and produces transverse wrinkles in the forehead when one frowns.

Muscles Around the Mouth

The sphincter of the mouth is orbicularis oris and the dilator muscles radiate outward from the lips like the spokes of a wheel.

Orbicularis Oris Muscle (p. 660)

This muscle encircles the mouth and is the sphincter of the oral aperture
This muscle (1) closes the lips, (2) protrudes them and (3) compresses them against the teeth.
It plays an important role in articulation and mastication. Together with the buccinator muscle, it helps to hold the food between the teeth during mastication.

Zygomaticus Major Muscle (p. 660)

It extends from the zygomatic bone to the angle of the mouth.
It draws the corner of the moth superolaterally during smiling and laughing.

Zygomaticus Minor Muscle (p. 660)

This is a narrow slip of muscle, and passes obliquely from the zygomatic bone to the orbicularis oris.
It helps raise the upper lip when showing contempt or to deepen the nasolabial sulcus when showing sadness.

The Buccinator Muscle (p. 660)

This is a thin, flat, rectangular muscle.
It is attached laterally to the alveolar processes of the maxilla and mandible, opposite the molar teeth and the pterygomandibular raphe.
Medially, its fibres mingle with those of orbicularis oris.

Innervation: the buccal branch of facial.
It aids mastication and swallowing by pushing the cheeks against the molar teeth during chewing.

Muscles Around the Eyelids

The function of the eyelid (L. palpebrae) is to protect the eye from injury and excessive light. It also keeps the cornea moist.

The Orbicularis Oculi Muscle (p. 660)

This is the sphincter muscle of the eye.
Its fibres sweep in concentric circles around the orbital margin and eyelids.
It narrows the eye and helps the flow of tears from the lacrimal sac.

This muscle has 3 parts: (1) a thick orbital part for closing the eyes to protect then from light and dust; (2) a thin palpebral part for closing the eyelids lightly to keep the cornea from drying; and (3) a lacrimal part for drawing the eyelids and lacrimal punta medially.

When all three parts of the orbicularis oculi contract, the eyes are firmly closed and the adjacent skin becomes wrinkled.
The zygomatic branch of the facial nerve (CN VII) supplies it.

The Levator Palpebrae Superioris Muscle (p. 660)

This muscle raises the upper eyelid to open the palpebral fissure.
It is supplied by the oculomotor nerve (CN III).

Muscles Around the Nose

The Nasalis Muscle (p. 660)

This muscle consists of a transverse (compressor naris) and alar (dilator naris) parts.
It is supplied by the buccal branch of the facial nerve.

Nerves of the Face

Innervation of the Muscles of Facial Expression

The Facial Nerve (CN VII) (pp. 664-5)

Click here to go to its entry under cranial nerves.

The seventh cranial nerve supplies the superficial muscle of the neck (platysma), the muscles of facial expression, the auricular muscles and the scalp muscles.
CN VII is the sole motor supply to the muscles of facial expression.

The facial nerve emerges from the skull though the stylomastoid foramen.
Almost immediately, it enters the parotid gland. It runs superficially in this gland before giving rise to its five terminal branches: temporal, zygomatic, buccal, marginal mandibular, and cervical.
These nerve emerge from the superior, anterior and inferior margins of the gland and spread out like the abducted digits of the hand to supply the muscles of facial expression.

The temporal branches of CN VII cross the zygomatic arch to supply all the superficial facial muscles superior to it, including the orbital and forehead muscles.

The zygomatic branch of CN VII passes transversely over the zygomatic bone to supply the muscles in the zygomatic, orbital and infraorbital regions.

The buccal branches of CN VII pass horizontally, external to the masseter muscle, to supply the buccinator and the muscles of the upper lip.

The marginal mandibular branch of CN VII supplies the muscles of the lower lip and chin.

The cervical branch of CN VII supplies the platysma and the superficial muscles of the neck.

Innervation of the Skin (pp. 661-4)

Click here for a diagram of the sensory nerves of the skin.

Innervation of the skin is mainly through the three branches of the trigeminal nerve (CN V).
Some skin over the angle of the mandible and anterior and posterior of the auricle is supplied by the great auricular nerve from the cervical plexus.
Some cutaneous branches of the auricular branch of the facial nerve also supplies skin on both sides of the auricle.

The trigeminal nerve is the general sensory nerve to the head, particularly the face, and is the motor nerve to the muscles of mastication.

The Ophthalmic Nerve (p. 661)

This is the superior division of the trigeminal nerve, the smallest of the three branches and is wholly sensory.
The ophthalmic nerve divides into three branches: the nasociliary, frontal and lacrimal just before entering the orbit through the superior orbital fissure.

The nasociliary nerve supplies the tip of the nose through the external nasal branch of the anterior ethmoidal nerve.

The frontal nerve is the direct continuation of CN V¹ and divides into two branches, the supraorbital and supratrochlear.
The supratrochlear nerve supplies the middle part of the forehead.
The supraorbital nerve supplies the lateral part and the front of the scalp.

The lacrimal nerve, the smallest of the main ophthalmic branches, emerges over the superolateral orbital margin to supply the lacrimal gland and the lateral part of the upper eyelid.

The Maxillary Nerve (p. 661)

This is the intermediate division of the trigeminal nerve.
It has three cutaneous branches.

The infraorbital nerve is the largest terminal branch of the maxillary nerve.
It passes through the infraorbital foramen and breaks up into branches that supplies the skin on the lateral aspect of the nose, upper lip and lower eyelid.

The zygomaticofacial nerve, a small branch of the maxillary, emerges from the zygomatic bone from a foramen with the same name.
It supplies the skin over the zygomatic bone.

The zygomaticotemporal nerve emerges from the zygomatic bone from foramen of the same name.
It supplies the skin over the temporal region.

The Mandibular Nerve (pp. 661-4)

This is the inferior division of the trigeminal nerve.
Of the three division of the trigeminal nerve, CN V³ is the only one that carries motor fibres (to the muscles of mastication).
The main sensory branches of the mandibular nerve are the buccal, auriculotemporal, inferior alveolar and lingual nerves.

The buccal nerve is a small branch of the mandibular that emerges from deep to the ramus of the mandible.
It supplies the skin of the cheek over the buccinator muscle, the mucous membrane lining the cheek, and the buccal surface of the gingiva.

The auriculotemporal nerve passes medially to the neck of the mandible and then turns superiorly, posterior to its head and anterior to the auricle. It then crosses over the root of the zygomatic process of the temporal bone, deep to the superficial temporal artery.

It supplies the auricle, external acoustic meatus, tympanic membrane, and the skin in the temporal region.

The inferior alveolar nerve is the large terminal branch of the posterior division of the mandibular nerve (the lingual nerve is the other terminal branch).
It enters the mandible through the mandibular foramen to the mandibular canal. In the canal, it gives branches to the mandibular teeth.
Opposite the mental foramen, this nerve divides into the mental nerve and the incisive nerve.
The incisive nerve supplies the incisor teeth, the adjacent gingiva and the mucosa of the lower lip.
The mental nerve emerges from the mental foramen and supplies the skin of the chin and the skin and mucous membrane of the lower lip and gingiva.

The lingual nerve is the smaller terminal branch of the mandibular nerve.
It supplies the general sensory fibres to the anterior two-thirds of the tongue, the floor of the mouth and the gingivae of the mandibular teeth.

The Arteries of the Face

The superficial arteries are derived from the external carotid arteries.

The Facial Artery (pp. 665-6)

This is the chief artery of the face.
It arises from the external carotid artery and winds its way to the inferior border of the mandible, just anterior to the masseter muscle.
It hooks around the inferior border of the mandible and grooves the bone. Here the artery is superficial, just beneath the platysma and its pulsation can be felt.

In its course over the face to the medial angle of the eye, the facial artery crosses the mandible, buccinator muscle, and maxilla.
It lies deep to the zygomaticus major.

The facial artery ends by sending branches to the lip and side of the nose.
The part of the artery that runs along the side of the nose to supply the eyelids is called the angular artery.

The Superficial Temporal Artery (p. 666)

This artery is the smaller of the two terminal branches of the external carotid artery (the other is the maxillary artery).
It begins deep to the parotid gland, posterior to the neck of the mandible, and ascends superficial to the posterior end of the zygomatic process of the temporal bone. It then enters the temporal fossa.

The superficial temporal artery ends in the scalp by dividing into the frontal and parietal branches.

Pulsation of this artery can be felt by compressing the root of the zygomatic process of the temporal bone.

The Transverse Facial Artery (p. 666)

This small artery arises from the superficial temporal artery before it emerges from the parotid gland.
It crosses the face superficial to the masseter muscle, about a fingerbreadth inferior to the zygomatic arch.
It divides into numerous branches that supply the parotid gland and duct, the masseter muscle, and the skin of the face.

It anastomoses with branches of the facial artery.

Veins of the Face

Click here for a diagram on the superficial veins of the face and neck.

The Supratrochlear Vein (p. 667)

This vessel begins on the forehead from a network of veins connected to the frontal tributaries of the superficial temporal vein.
It descends near the medial plane with its fellow on the other side.
These veins diverge near the orbits, each joining a supraorbital vein to form the facial vein near the medial canthus (angle of the eye).

The Supraorbital Vein (p. 667)

This vessel begins near the zygomatic process of the temporal bone.
It joins the tributaries of the superficial and middle temporal veins.
It passes medially and joins the supratrochlear vein to form the facial vein near the medial canthus.

The Facial Vein (pp. 667)

This vein provides the major venous drainage of the face.

It begins at the medial canthus of the eye by the union of the supraorbital and supratrochlear veins.
It runs inferoposteriorly through the face, posterior to the facial artery, but takes a more superficial and straighter course than the artery.
Inferior to the margin of the mandible, the facial vein is joined by the anterior branch of the retromandibular vein.
The facial veins ends by draining into the internal jugular vein.

The Superficial Temporal Vein (p. 667)

This vein drains the forehead and scalp and receives tributaries from the veins of the temple and face.
In the region of the temporomandibular joint, this vein enters the parotid gland.

The Retromandibular Vein (p. 668)

The union of the superficial temporal and maxillary veins forms this vessel, posterior to the neck of the mandible.
It descends within the parotid gland, superficial to the external carotid artery but deep to the facial nerve.
It divides into an anterior branch that unites with the facial vein, and a posterior branch that joins the posterior auricular vein to form the external jugular vein.