Cheeks

The cheeks form the lateral walls of the oral cavity and contribute to the external contour of the face. Each cheek extends from the lateral margin of the mouth toward the lateral facial region and separates the oral cavity internally from the external surface of the face.

The structural core of the cheek is formed principally by the buccinator muscle. Superficial to the buccinator are facial muscles, connective tissue, vessels, nerves, and variable amounts of adipose tissue. Deep to the muscle is the buccal mucosa, which forms the inner lining of the cheek.

The cheeks have important roles in mastication, swallowing, speech, facial expression, and maintenance of food between the occlusal surfaces of the teeth. They are also closely related to the parotid duct, which crosses the buccinator externally and then pierces it to enter the oral cavity.

Location of the Cheeks

The cheeks occupy the lateral portions of the face on either side of the oral cavity.

Externally, they extend between the mouth and more lateral facial structures. Internally, their mucosal surfaces face the teeth, gingivae, and oral vestibule.

Cheeks and the Oral Cavity

The cheeks form the lateral boundaries of the oral vestibule.

The oral vestibule is the space between the lips and cheeks externally and the teeth and gingivae internally.

Oral Vestibule

The oral vestibule communicates with the exterior through the oral fissure.

When the teeth are occluded, it communicates posteriorly with the oral cavity proper through spaces behind the last molar teeth.

General Structure of the Cheek

The cheek is composed of several tissue layers rather than a single anatomical structure.

From superficial to deep, these include skin, superficial connective tissue, facial musculature, buccal fat and associated fascial tissues, buccinator muscle, submucosal tissue, and oral mucosa.

Layers of the Cheek

Layer	Main Features
Skin	External covering of the cheek
Superficial fascia	Contains fat, vessels, nerves and facial muscles
Facial muscles	Contribute to facial expression and movement of the mouth
Buccal fat	Provides cushioning and contributes to facial contour
Buccinator	Principal muscular component of the cheek wall
Submucosa	Contains connective tissue and minor salivary glands
Buccal mucosa	Internal lining facing the oral cavity

Skin of the Cheek

The external surface of the cheek is covered by facial skin.

Its thickness and the amount of underlying subcutaneous tissue vary between individuals and between different regions of the cheek.

Superficial Fascia

The superficial fascia contains adipose tissue, vessels, cutaneous nerves, and muscles of facial expression.

Unlike many regions of the body, facial muscles are closely associated with the skin and contribute directly to movements of the facial surface.

Muscular Framework

The principal muscle forming the cheek wall is the buccinator.

Several other muscles of facial expression overlap or blend with tissues of the cheek, particularly near the angle of the mouth.

Buccinator Muscle

The buccinator is a thin, quadrilateral muscle forming the muscular foundation of the cheek.

It lies deep to several other muscles of facial expression and separates the oral mucosa from more superficial cheek tissues.

Attachments of the Buccinator

The buccinator arises from the alveolar processes of the maxilla and mandible opposite the molar teeth and from the pterygomandibular raphe.

Its fibers pass toward the angle of the mouth and blend with fibers of the orbicularis oris and other muscles around the oral aperture.

Maxillary Attachment

Superiorly, the buccinator attaches to the alveolar part of the maxilla in the molar region.

Mandibular Attachment

Inferiorly, the muscle attaches to the alveolar part of the mandible near the molar teeth.

Pterygomandibular Raphe

Posteriorly, the buccinator arises partly from the pterygomandibular raphe, a fibrous band extending between the pterygoid hamulus superiorly and the posterior mandibular region inferiorly.

The raphe also provides attachment for the superior pharyngeal constrictor.

Anterior Buccinator Fibers

Anteriorly, buccinator fibers converge toward the angle of the mouth.

They interlace with fibers of orbicularis oris and participate in the complex muscular arrangement surrounding the oral aperture.

Function of the Buccinator

The buccinator compresses the cheek against the teeth and gingivae.

This action prevents food from accumulating within the oral vestibule during mastication and helps return food toward the occlusal surfaces of the teeth.

Buccinator During Mastication

During chewing, movements of the tongue tend to position food from the medial side while the buccinator acts from the lateral side.

Together, these structures help maintain the food bolus between the upper and lower teeth.

Buccinator and Blowing

Contraction of the buccinator can increase pressure within the oral cavity when the lips are closed or narrowed.

This contributes to actions such as blowing and whistling.

Buccinator and Sucking

The buccinator also contributes to sucking by helping maintain the position and tension of the cheek wall.

This function is particularly important during feeding in infants.

Buccinator and Facial Expression

Although functionally important during mastication, the buccinator is classified as a muscle of facial expression.

Its motor innervation therefore comes from the facial nerve rather than the mandibular division of the trigeminal nerve.

Orbicularis Oris

The orbicularis oris surrounds the oral aperture and interacts extensively with fibers from the buccinator and other facial muscles.

The continuity between these muscles helps coordinate movements of the lips and cheeks.

Modiolus

The modiolus is a fibromuscular region located near each angle of the mouth where several facial muscles converge and interlace.

Buccinator fibers contribute to this complex arrangement.

Muscles Associated With the Cheek

Several muscles of facial expression are related to the cheek and angle of the mouth, including:

• Zygomaticus major
• Zygomaticus minor
• Risorius
• Levator anguli oris
• Depressor anguli oris
• Orbicularis oris
• Buccinator

Buccal Fat Pad

The buccal fat pad is an encapsulated collection of adipose tissue located in the cheek region.

It lies in close relationship to the buccinator and contributes to the contour and mechanical properties of the cheek.

Location of the Buccal Fat Pad

A portion of the buccal fat pad lies superficial to the buccinator and deep to more superficial facial tissues.

Extensions of the fat pad reach neighboring anatomical regions.

Function of the Buccal Fat Pad

The buccal fat pad provides cushioning between muscles and facilitates movement of adjacent structures.

It also contributes to the external contour of the cheek.

Buccal Fat Pad in Infants

The buccal fat pad is relatively prominent in infants.

Its presence helps support the cheek during sucking and contributes to the characteristic fullness of the infant cheek.

Buccal Mucosa

The internal surface of the cheek is lined by buccal mucosa.

This mucosa is continuous anteriorly with the mucosa of the lips and posteriorly with mucosal surfaces approaching the oropharyngeal region.

Epithelium of the Buccal Mucosa

The buccal mucosa is generally lined by nonkeratinized stratified squamous epithelium.

This lining provides protection against mechanical forces while remaining flexible enough to accommodate movements of the cheek.

Submucosa of the Cheek

Deep to the buccal mucosa is connective tissue containing vessels, nerves, adipose tissue, and minor salivary glands.

The mobility of the mucosa over underlying tissues varies according to location.

Buccal Glands

Numerous small buccal glands are located within the submucosal tissues of the cheek.

These are minor salivary glands whose secretions contribute to lubrication of the oral mucosa.

Molar Glands

Minor salivary glands near the molar region may be referred to as molar glands.

Their ducts open onto the oral mucosal surface.

Parotid Duct

The parotid duct, also called Stensen's duct, carries saliva from the parotid gland into the oral cavity.

Its relationship to the cheek is one of the most important anatomical features of this region.

Course of the Parotid Duct

The parotid duct emerges from the anterior border of the parotid gland and travels horizontally across the surface of the masseter muscle.

Near the anterior border of the masseter, it turns medially toward the oral cavity.

Parotid Duct and Buccinator

After turning medially, the parotid duct passes through cheek tissues and pierces the buccinator muscle.

It then passes through the buccal mucosa to open into the oral vestibule.

Parotid Papilla

The opening of the parotid duct is located on a small elevation of the buccal mucosa called the parotid papilla.

The papilla is usually located opposite the crown of the maxillary second molar tooth.

Parotid Duct Pathway

Stage	Relationship
Origin	Anterior border of parotid gland
Facial course	Crosses masseter
Turn	Turns medially near anterior border of masseter
Cheek passage	Pierces buccinator
Opening	Parotid papilla in oral vestibule
Landmark	Usually opposite maxillary second molar

Masseter and the Cheek

The masseter lies posterior and lateral to much of the cheek region.

The parotid duct crosses its superficial surface before turning medially to penetrate the cheek.

Blood Supply of the Cheek

The cheek receives arterial blood from several branches of the external carotid arterial system.

Important contributors include the facial artery, buccal artery, transverse facial artery, and infraorbital arterial branches.

Facial Artery

The facial artery is a major arterial supply to the superficial face and contributes branches to the cheek.

After crossing the inferior border of the mandible, it follows a tortuous course across the face toward the medial angle of the eye.

Buccal Artery

The buccal artery is typically a branch of the maxillary artery.

It accompanies the buccal nerve and contributes to the blood supply of the buccinator and buccal mucosa.

Transverse Facial Artery

The transverse facial artery usually arises from the superficial temporal artery within the parotid region.

It travels across the face and contributes to the vascular supply of the lateral cheek.

Infraorbital Artery

Branches of the infraorbital artery emerge through the infraorbital foramen and contribute to the blood supply of the upper cheek.

Arterial Supply Summary

Artery	Typical Contribution
Facial artery	Major superficial facial and cheek supply
Buccal artery	Buccinator and buccal mucosa
Transverse facial artery	Lateral cheek
Infraorbital artery	Upper cheek region

Venous Drainage

Venous drainage of the cheek occurs through several interconnected facial and deep facial veins.

These channels ultimately communicate with both superficial facial veins and deeper venous networks.

Facial Vein

The facial vein receives venous blood from substantial portions of the superficial face, including the cheek.

It descends across the face and contributes to venous drainage toward the internal jugular venous system.

Deep Facial Vein

The deep facial vein provides a communication between the facial vein and the pterygoid venous plexus.

This connection is clinically important because it links superficial and deep venous pathways of the face.

Pterygoid Venous Plexus

The pterygoid venous plexus is a network of veins within the infratemporal region.

It communicates with facial venous channels and other deep veins of the head.

Motor Innervation of the Cheek

The buccinator is supplied by motor branches of the facial nerve (cranial nerve VII).

Buccal branches of the facial nerve reach the muscle from its superficial aspect.

Buccal Branches of the Facial Nerve

After emerging from the parotid gland, buccal branches of the facial nerve travel across the face to supply muscles of facial expression in the cheek and upper lip region.

These branches are motor rather than general sensory nerves.

Sensory Innervation of the Cheek

Sensation from the cheek is supplied primarily by branches of the trigeminal nerve.

Different portions of the external skin and internal mucosa receive fibers from different trigeminal divisions.

Buccal Nerve

The buccal nerve, also called the long buccal nerve, is a sensory branch of the mandibular division of the trigeminal nerve (CN V3).

It supplies general sensation to the buccal mucosa and portions of the skin of the cheek.

Buccal Nerve Versus Buccal Branch of Facial Nerve

The buccal nerve and buccal branches of the facial nerve are distinct structures with different functions.

Structure	Parent Nerve	Primary Function
Buccal nerve	Mandibular nerve, CN V3	General sensory innervation
Buccal branches of facial nerve	Facial nerve, CN VII	Motor supply to facial muscles

Infraorbital Nerve

The infraorbital nerve, a continuation of the maxillary division of the trigeminal nerve, contributes sensory innervation to the upper cheek.

Its terminal branches emerge from the infraorbital foramen.

Mental Nerve

The mental nerve, a terminal branch of the inferior alveolar nerve from CN V3, supplies sensation to the skin of the chin and lower lip and contributes to sensation near the lower anterior facial region.

Lymphatic Drainage of the Cheek

Lymph from the cheek drains primarily toward submandibular lymph nodes, with additional drainage pathways depending on the precise region.

Lymph ultimately reaches the deep cervical lymphatic chain.

Submandibular Lymph Nodes

The submandibular nodes receive lymph from substantial portions of the cheek, nose, lips, gingivae, and other facial structures.

Parotid Lymph Nodes

More lateral and superior portions of the cheek may communicate with lymphatic pathways associated with the parotid region.

Cheeks During Mastication

The cheeks play an active role during chewing rather than functioning merely as passive walls of the mouth.

Buccinator contraction prevents food from collecting between the teeth and cheek and redirects displaced material toward the dental occlusal surfaces.

Cheeks and the Tongue

The tongue and cheeks act together during mastication.

The tongue manipulates food from the medial side, while the buccinator helps control it from the lateral side.

Cheeks During Swallowing

Before swallowing, the cheeks assist in maintaining the food bolus within the oral cavity while the tongue organizes and propels it posteriorly.

Effective cheek tone helps prevent food from remaining within the vestibule.

Cheeks and Speech

Changes in cheek tension contribute to control of the oral cavity during speech.

The cheeks function together with the lips, tongue, palate, mandible, and other structures involved in articulation.

Cheeks and Facial Expression

Movements of the cheek are produced by coordinated activity of several muscles of facial expression.

These movements contribute to smiling, grimacing, compression of the lips, and other facial expressions.

Facial Nerve Injury

Injury to the facial nerve can weaken or paralyze the buccinator and other muscles of facial expression.

Loss of buccinator function can allow food to accumulate between the cheek and teeth during eating.

Buccal Nerve Injury

Damage to the buccal nerve affects sensory innervation rather than motor function of the buccinator.

This distinction reflects the separate trigeminal sensory and facial motor innervation of the cheek.

Parotid Duct Injury

Because the parotid duct crosses the lateral face and passes through the cheek, facial trauma or surgical procedures in this region can damage the duct.

Disruption may interfere with normal drainage of parotid saliva into the oral vestibule.

Parotid Duct Obstruction

Obstruction of the parotid duct can impair salivary drainage and may produce painful swelling of the parotid gland, particularly during stimulation of salivary secretion.

Examination of the Parotid Duct Opening

The parotid papilla can be inspected on the buccal mucosa opposite the maxillary second molar.

This provides a useful surface landmark for identifying the intraoral opening of the parotid duct.

Cheek Biting

The buccal mucosa can be traumatized when it becomes trapped between the teeth.

Repeated mechanical irritation may produce localized changes along the occlusal level of the cheek.

Linea Alba

A horizontal whitish line may appear on the buccal mucosa at approximately the level of dental occlusion.

This feature, commonly called the linea alba, is associated with chronic friction or pressure against the teeth.

Oral Mucosal Lesions

Because the buccal mucosa is easily visible during oral examination, changes in its color, texture, thickness, or surface can often be detected directly.

The cheek is therefore an important region in routine examination of the oral cavity.

Buccal Space

The buccal space is a potential fascial space within the cheek region associated with the buccinator and surrounding soft tissues.

It contains structures including buccal fat, vessels, nerves, minor salivary tissue, and portions of the parotid duct pathway.

Buccal Space Infection

Infection originating from teeth or surrounding structures can spread into the buccal space.

The resulting swelling may be visible externally over the cheek or internally within the oral vestibule depending on the anatomical route of spread.

Dental Infections and the Cheek

Infections arising from maxillary or mandibular teeth may extend into adjacent facial spaces.

The relationship between tooth roots, muscle attachments, and fascial planes influences the direction in which infection spreads.

Buccal Fat Pad in Surgery

The buccal fat pad can be mobilized surgically because of its accessible location and vascularity.

It may be used in selected reconstructive procedures involving defects of the oral cavity.

Cheek Trauma

Penetrating or blunt trauma to the cheek may involve multiple structures because vessels, facial nerve branches, sensory nerves, muscles, and the parotid duct occupy the region.

Assessment therefore requires consideration of both superficial and deep anatomy.

Facial Lacerations

Deep cheek lacerations can damage muscles of facial expression, facial nerve branches, vessels, or the parotid duct.

The anatomical level and location of the wound help determine which structures may be involved.

Buccal Mucosal Examination

The buccal mucosa can be examined by retracting the cheek laterally.

Important visible landmarks include the parotid papilla, dental occlusal line, gingivobuccal reflections, and general mucosal surface.

Surface Anatomy of the Cheek

The external cheek does not correspond to a single muscle or fascial compartment.

Its visible contour reflects the combined effects of facial bones, muscles, buccal fat, subcutaneous tissue, skin, and neighboring structures.

Relationship to the Maxilla

The superior and medial framework of the cheek is closely related to the maxilla and its alveolar process.

The maxillary molar region also provides part of the attachment of the buccinator.

Relationship to the Mandible

The inferior portion of the cheek is related to the body and ramus of the mandible.

The mandibular alveolar region near the molar teeth provides attachment for the lower portion of the buccinator.

Relationship to the Zygomatic Bone

The zygomatic bone contributes to the skeletal prominence of the upper lateral cheek.

It provides attachment or anatomical relationships for several structures contributing to facial contour and expression.

Relationship to the Oral Vestibule

The buccal mucosal surface faces the oral vestibule and is separated from the external skin by the layered tissues of the cheek.

This arrangement allows the cheek to remain mobile while maintaining the lateral boundary of the mouth.

Cheek Anatomy Summary

Feature	Anatomy
Principal muscle	Buccinator
Internal lining	Buccal mucosa
Typical mucosal epithelium	Nonkeratinized stratified squamous epithelium
Major salivary duct	Parotid duct
Parotid duct opening	Opposite maxillary second molar
Motor supply to buccinator	Facial nerve, CN VII
Important sensory nerve	Buccal nerve, CN V3
Major arterial contributors	Facial, buccal, transverse facial and infraorbital arteries
Major lymphatic pathway	Primarily submandibular nodes

Key Anatomical Relationships

Structure	Relationship to the Cheek
Buccinator	Forms principal muscular wall
Buccal fat pad	Located in deep cheek tissues, partly superficial to buccinator
Parotid duct	Crosses masseter, turns medially and pierces buccinator
Buccal nerve	Provides sensory innervation to buccal region
Facial nerve branches	Provide motor innervation to facial muscles
Oral vestibule	Lies medial to cheek and lateral to teeth and gingivae

Functional Importance

The cheeks form mobile lateral walls of the oral cavity and participate actively in oral function. The buccinator maintains tension within the cheek and presses it against the teeth, preventing food from collecting in the oral vestibule during mastication.

The internal buccal mucosa provides a flexible protective surface, while minor salivary glands contribute to lubrication. The parotid duct traverses the cheek and delivers saliva from the parotid gland into the oral vestibule opposite the maxillary second molar.

The region also illustrates an important distinction in cranial nerve anatomy. Motor control of the buccinator is provided by the facial nerve, while general sensory innervation of much of the buccal mucosa is provided by the buccal branch of the mandibular division of the trigeminal nerve. These anatomical relationships make the cheek important in dentistry, oral examination, facial surgery, trauma assessment, and evaluation of salivary duct disorders.