The tissue that lines the inside of the mouth is known as the basal mucosa and is composed of squamous epithelial cells. These structures, commonly thought of as cheek cells, divide approximately every 24 hours and are constantly shed from the body.

Cheek cells secrete a continuous supply of mucin, the principal element of mucous. In combination with the salivary glands, the mucin maintains a moist environment in the oral cavity. A sufficient moisture content must be continually sustained in order to aid enzymes in softening food, facilitate swallowing, and initiate the process of digestion.

Cheek cells are often studied in school laboratory settings because they can be easily obtained through a mouth rinse or simple swab. Yet, though the individual cells appear very simple under the microscope, they each contain the genetic make-up of the entire body. Thus, they are often used for DNA fingerprinting studies, as well as paternity testing. Interestingly, a group of Australian researchers have recently found another use for human cheek cells. They have devised a test that utilizes cheek cells to measure an individual’s proclivity for high blood pressure.