Cheeks

Overview

The cheeks are the lateral boundaries of the oral cavity and form an integral part of the facial and digestive anatomy. They contribute to various functions including mastication (chewing), speech, facial expression, and sensory perception. In the context of the digestive system, the cheeks help contain food during chewing and guide it toward the teeth and oral cavity proper.

Location

The cheeks are located on the lateral sides of the face. They:

• Extend from the zygomatic arch (cheekbone) superiorly to the mandibular border inferiorly

• Lie anterior to the masseter muscle and posterior to the lips

• Form the lateral walls of the oral vestibule, the space between the teeth/gums and the inner mucosa of the lips and cheeks

Structure

The cheeks are composed of multiple layers that provide structure, flexibility, and function:

• Skin: The outermost layer, continuous with the facial skin

• Subcutaneous tissue: Contains fat and the prominent buccal fat pad, which gives the cheek its fullness

• Muscle layer: Primarily the buccinator muscle, which forms the muscular framework and is important for mastication and facial expression

• Buccal mucosa: The inner lining of the cheek composed of stratified squamous epithelium, providing a moist surface within the mouth

The cheeks are richly supplied by branches of the facial artery and vein and are innervated by:

• Facial nerve (CN VII): Motor innervation to the buccinator muscle

• Buccal branch of the mandibular nerve (CN V3): Sensory innervation to the inner cheek mucosa

Function

The cheeks serve several key functions in both digestive and non-digestive roles:

• Containment: Hold food between the teeth during chewing to prevent it from escaping the oral cavity

• Assistance in mastication: Help manipulate and position food for effective grinding by the molars

• Speech and expression: Essential in forming certain sounds and in nonverbal facial communication

• Protective barrier: Provide a buffer for the oral cavity, protecting inner tissues from trauma and heat

Physiological Role(s)

The cheeks contribute to digestive physiology in the following ways:

• Facilitating chewing: Coordinate with the tongue and teeth to ensure food is properly masticated and formed into a bolus

• Maintaining oral pressure: The buccinator muscle maintains intraoral pressure, aiding in swallowing and preventing food from accumulating in the vestibule

• Lubrication: The buccal mucosa is kept moist by minor salivary glands, helping in taste, swallowing, and oral hygiene

Clinical Significance

Several conditions and procedures are associated with the cheeks:

• Buccal mucosa lesions: May include ulcers, leukoplakia, or oral cancers; often examined during routine dental or ENT checkups

• Parotid duct obstruction: The opening of the parotid (Stensen’s) duct is located opposite the upper second molar on the inner cheek; blockages can lead to pain and swelling

• Facial trauma: Fractures of the zygomatic arch or cheekbone can affect both form and function of the cheek

• Buccal fat pad removal: Aesthetic surgery sometimes involves removing this fat pad to achieve a slimmer facial appearance

• Cleft cheek (rare): A rare congenital anomaly associated with craniofacial syndromes

• Cheek biting or bruxism: Habitual biting of the inner cheek can cause chronic irritation, ulcers, or fibrous nodules

Evaluation of cheek health is essential in dental, maxillofacial, and gastrointestinal assessments. Their role in the initial phases of digestion underscores their importance beyond facial appearance or expression.