Cheek

The cheek is the fleshy part of the face located between the mouth and ear, extending downward from the eye to the lower jaw. It forms part of the outer wall of the mouth: inside it is lined with oral mucosa, while outside it is skin. Most people have two cheeks, one on each side of the face.

The cheek is not merely a cosmetic feature; it plays a functional role in eating, speech, and facial expression. When food is chewed, the muscles of the cheek move the food toward the teeth so it can be further broken down.

Structure

The cheek's layers consist of skin, subcutaneous fat, facial muscle, and inner mucosa. The most important muscle is the buccinator, which forms the wall of the cheek, along with facial expression muscles such as the zygomaticus, which lifts the corners of the mouth when smiling. The masseter, a powerful chewing muscle, lies at the back of the cheek and can be felt when the jaw is clenched.

Within the cheek lies the parotid duct, which carries saliva from the parotid gland into the mouth near the upper back teeth. There is also specialized subcutaneous tissue unique to infants, which aids in suckling.

Nerves and blood supply

Sensation in the cheek skin is provided by branches of the trigeminal nerve (the fifth cranial nerve). Facial muscle movement is controlled by the facial nerve. Blood is supplied by branches of the facial artery and other vessels arising from the external carotid artery.

Health and culture

The cheek can be affected by infections of the mouth, cavities from dental decay, or injuries from trauma. Inflammation of the parotid gland, such as mumps, causes swelling of the cheek and lower jaw. Culturally, cheek pinching and kissing on the cheek are gestures that vary across societies, while reddened cheeks are often associated with health and youthfulness in many cultures.