3 Superficial Face

STUDYAIMS

At the end of your study, you should be able to:

Outline the main muscles of facial expression and their actions

Know the layers of the scalp, its innervation and vascular supply

Understand the vascular supplyand lymphatic drainage of the face

Know the sensoryand motor innervation of the face

Outline the main muscles of mastication and their actions

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GUIDE

Head and Neck: Superficial Face

[Plate 25, Muscles of Facial Expression: Lateral View]

Face

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Subcutaneous tissue of face

Contains muscles of facial expression

Contains varying amount of fat-for example, buccal fat pads of the cheek

Highlyvascular

Contains sensorybranches of trigeminal (V) nerve, upper cervical spinal nerves and motor branches of the facial nerve (VII)

Traversed byskin ligaments (retinacula cutis)

Bands of connective tissue

Connect skin to bones Muscles of facial expression

The muscles of facial expression are in several ways unique among the skeletal muscles of the body. Theyall originate embryologically from the second pharyngeal arch and are all innervated byterminal branches of the facial nerve (cranial nerve [CN] VII).Additionally, most arise from the bones of the face or fascia, and insert into the dermis of the skin overlying the scalp, face, and anterolateral neck.

Lie within superficial fascia

Most arise from bone and insert into skin

Arranged as sphincters or dilators around orifices of face

Innervated byone of five main branches of facial nerve (occipitalis innervated byposterior auricular branch) Muscles related to the orbit

Orbicularis oculi

Composed of three parts: lacrimal, palpebral, orbital

Lacrimal part draws eyelids and lacrimal puncta mediallyto drain tears

Inner palpebral part gentlycloses eyelids (blinking)

Outer orbital part that tightlycloses eyelids (squinting)

Corrugator supercilii

Draws medial end of eyebrow mediallyand inferiorlyfor a concerned look

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Wrinkles skin of forehead

Frontalis portion of occipitofrontalis

Elevates the eyebrows for a surprised look

Wrinkles the forehead

Muscles related to the nose

Nasalis

Consists of compressor naris-compresses nostril

And dilator naris-flares nostrils

Procerus

From forehead over bridge of nose

Draws medial eyebrow inferiorly

Creates transverse wrinkles over nose-frowning

Muscles related to the ear

Anterior, superior, and posterior auricular

Variablydeveloped

Muscles related to mouth and lips

Orbicularis oris

Sphincter of the mouth

Important for speech, holding food between the teeth, whistling, blowing

Levator labii superioris alaeque nasi

Elevates nose and upper lip

Mentalis

Wrinkles skin on chin

Buccinator

Involved in smiling

Holds food between teeth during chewing

Used in whistling, sucking, and horn blowing

Depressor anguli oris

Depresses angle of mouth

Levator anguli oris

Elevates corner of mouth

Levator labii superioris

Lifts and everts upper lip

Depressor labii inferioris

Draws lip down and laterally

Used to show impatience

Risorius

Draws corner of mouth laterally

Used in grinning

Zygomaticus major

Draws angle of mouth up and laterally

Used in smiling and laughing

Zygomaticus minor

Raises upper lip as when showing contempt

Platysma

Depresses mandible

Draws corners of mouth down

Used when grimacing

Scalp

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Extends from superior nuchal line to superior orbital ridge

Laterallyextends to external acoustic meatus and zygomatic arch

Composed of five layers

First three are adherent to skull, move as one

Skin (1)

Contains sweat and sebaceous glands and hair follicles

Well vascularized

Connective Tissue (2)

Dense

Well vascularized and innervated

Aponeurosis of occipitofrontalis muscle (3)

Tendinous sheet

Connects occipitalis, frontalis and superior auricular muscles

Loose connective tissue (4)

Spongy

Layer that collects fluid from injuryof infection

Moves freelywith first three layers over pericranium

Periosteum of skull (5)

External periosteum of calvaria

Fairlyfirmlyattached to bone

Most tightlybound at suture lines

Vasculature of scalp

Scalp has rich blood supply, so bleeding from a scalp injuryis profuse

Arteries anastomoses

Branches of external carotid arteryto scalp

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Posterior auricular

Occipital

Superficial temporal

Branches of internal carotid arteryto scalp

Supratrochlear artery

Supraorbital artery

Venous drainage of scalp via veins of same name accompanying arteries

Deep aspects of scalp drain to deep temporal veins to pterygoid venous plexus

Innervation of scalp

Anterior to auricle: ophthalmic, maxillaryand mandibular divisions of cranial nerve (CN) V(trigeminal)

Posterior to auricle: cutaneous branches from C2 and C3 spinal nerves

Vascular supply of the face

Arteries

Facial artery

Major arterial source for face

Arises from external carotid artery, crosses mandible and traverses face to medial angle of eye

Branches to upper and lower lip and nose

Superficial temporal artery

Terminal branch of external carotid

Enters temporal fossa and ends in scalp

Transverse facial artery

From superficial temporal

Crosses face below zygomatic arch

Veins

Supratrochlear vein

Descends from forehead to nose

Joins supraorbital to form angular vein

Supraorbital vein

Begins in forehead and passes mediallyto join supratrochlear vein

Sends branch through supraorbital notch to joint superior ophthalmic vein

Facial vein

Two veins provide main venous drainage of face

Follow course of facial artery

Drain directlyor indirectlyinto internal jugular vein

Communicates with pterygoid venous plexus and cavernous sinus via superior ophthalmic vein

Superficial temporal vein

Drains scalp and forehead

Unites with maxillaryvein to form retromandibular vein

Retromandibular vein

Descends through parotid gland

Sends branch to facial vein

Joins posterior auricular vein to form external jugular vein

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Lymphatic drainage of the face

Superficial lymphatics travel with veins

Deep lymphatics travel with arteries

Lateral face → parotid lymph nodes

Upper lip and lateral lower lip → submandibular lymph nodes

Chin and central part of lower lip → submental lymph nodes

All lymphatic drainage eventuallyreaches the deep cervical lymph nodes

Innervation of the face

Cutaneous branches of the cervical nerves

From the cervical plexus

Innervate posterior neck, ear, and area over parotid gland

Trigeminal nerve (CN V)

Sensoryfor the face

Motor for muscles of mastication

Branches of ophthalmic nerve-CN V1

Nasociliarynerve → external nasal nerve to skin on dorsum of nose

Nasociliarynerve → infratrochlear nerve to skin and lower eyelid

Frontal nerve → supratrochlear nerve to skin in midforehead

Frontal nerve → supraorbital nerve to skin of forehead and upper eyelid

Branches of maxillarynerve-CN V2

Infraorbital nerve to skin of cheek, lower lid, lateral nose and mouth, upper lip

Zygomaticotemporal nerve to skin over anterior temple

Zygomaticofacial nerve to skin over zygomatic arch

Branches of mandibular nerve-CN V3

Auriculotemporal nerve-to skin of external ear, posterior temple, anterior to ear

Buccal nerve-to skin of cheek

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Mental nerve-to skin of chin and lower lip

Facial nerve

Sole motor supplyto muscles of facial expression

Has five main branches

Temporal

Zygomatic

Buccal

Mandibular

Cervical

Names refer to areas theysupply

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Other muscles associated with the face: Muscles of mastication

The muscles of mastication include four pairs of muscles (left and right side) that attach to the mandible, are embryological derivatives of the first pharyngeal arch, are all innervated bythe mandibular division of the trigeminal nerve (CN V3), and are important in biting and chewing food.

All attach to mandible

Responsible for biting and chewing (movements at the temporomandibular joint [TMJ]) All innervated bybranches of the mandibular nerve (CN V3)

All supplied bybranches of the maxillaryartery Group of four muscles

Temporalis

Large, fan-shaped

Covers most of the side of the head

Inserts on coronoid process of mandible

Masseter

Deep to parotid gland and crossed byparotid duct

Inserts on entire lateral surface of ramus of mandible except for condylar process

Lateral pterygoid

Deep to temporal muscle

Runs horizontallybackwards from infratemporal fossa and lateral pterygoid plate to insert on mandible

Covered with dense pterygoid plexus of veins

Medial pterygoid

Covered byinferior fibers of lateral pterygoid

Runs from inner surface of lateral pterygoid plate inferiorlyto inner surface of ramus of mandible

Muscle	Origin	Insertion	Main Actions	Nerve Supply	Blood Supply
Temporalis	Floor of temporal fossa	Coronoid	Elevates mandible; posterior	Mandibular	Superficial temporal and
	and deep temporal fascia	process and	fibers retrude mandible	nerve (V3)-deep	maxillaryarteries, middle,
		ramus of		temporal nerves	anterior, and posterior
		mandible			deep temporal arteries
Masseter	Zygomatic arch	Ramus of	Elevates and protrudes	Mandibular	Transverses facial artery;
		mandible	mandible; deep fibers retrude it	nerve (V3)-	masseteric branch of
		and coronoid		masseteric	maxillaryand facial
		process		nerve	arteries
Medial	Superior head:	Neck of	Acting together, protrude	Mandibular	Facial and maxillary
pterygoid	infratemporal surface of	mandible,	mandible and depress chin;	nerve (V3)-nerve	arteries
	greater wing of sphenoid	articular disc,	acting alone and alternately,	to medial
	Inferior head: lateral	and capsule	produces side-to-side	pterygoid
	pterygoid plate	of TMJ	movements
Lateral	Infratemporal surface of	Pterygoid	Together, protrude mandible,	Mandibular	Maxillaryartery-muscular
pterygoid	greater wing of sphenoid	fovea,	depress chin	nerve (V3)-	branches
	and lateral surface of	capsule of	Alone and alternately, side to	muscular
	lateral plate of pterygoid	TMJ and	side grinding	branches from
	plate	articular disk		anterior division

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