Cheek: anatomy, function, and variation in humans and animals

Anatomical components

The cheek comprises several layers: skin and subcutaneous fat, muscles of facial expression and mastication, mucous membrane that lines the mouth, and supporting connective tissue. The outer skin overlies the soft, often fleshy subcutaneous layer in many people. Important muscular and structural elements include the buccinator and parts of the orbicularis oris, alongside the lower facial bones such as the zygomatic arch and cheekbone. The lower boundary is shaped by the chin and the dental arcade, while deeper elements relate to the jaws and oral cavity.

Development and terminology

The word "buccal" is commonly used in medicine to describe the inner cheek or the side wall of the mouth; it derives from classical terms referring to the cheek. In humans the cheek tends to be prominent because of facial fat and musculature, whereas in other mammals cheek form and function are adapted to diet and lifestyle.

Functions and importance

Cheeks play a role in multiple everyday functions: they help hold and manipulate food during chewing, assist in swallowing, contribute to articulation of speech, and enable a wide range of facial expressions. The cheek's soft tissues also protect underlying bones and teeth from external impacts and provide an insulating layer for the face.

Variation across species and markings

Across animals, cheek size and structure vary widely. Some species possess expandable cheek pouches for temporary food storage, while others show distinctive coloration or stripe patterns on the cheek that aid in species identification or camouflage. These markings and structures are often used by biologists to distinguish individuals or related species.

Clinical and notable facts

The buccal mucosa is examined in dentistry and medicine because it can reveal signs of systemic disease, infection, or trauma. Injuries, swelling, and lesions of the cheek are managed by oral surgeons and dermatologists. Because cheeks influence both appearance and oral function, they are a focus in reconstructive surgery and cosmetic procedures as well as in studies of facial expression and communication.

For more on adjacent facial regions and related anatomy see face, nose, and the mouth wall described at oral cavity references. Additional resources include general anatomy texts and specialist literature on facial musculature and comparative mammalian adaptations (soft tissue, human anatomy, mammalian examples, cutaneous features, chin and jaw relations, zygomatic region).