Overview of the oral cavity

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The oral cavity can be defined, in simple terms, as the space within the mouth bounded by the jaw bones and surrounding muscles. It functions as the first part of the digestive system, allowing food to be tasted and broken down to form the food bolus, which is pushed back into the pharynx to initiate the process of deglutition (swallowing). Moreover, the oral cavity also has a role in the process of articulation, which is the modification of sounds to facilitate communication; it can also be an alternative route for the inhalation of air into the respiratory system.

The oral cavity can be divided in two regions:

• Oral vestibule: a space separating the gums and teeth from the lips and cheeks. It contains the vestibular part of the lips; the external part of the gingivae (labial or buccal gingivae); and the superior and inferior labial frenula.
• Oral cavity proper: space enclosed by the upper and lower dental arcades/teeth. The roof of the oral cavity proper is formed by the hard and soft palates, whereas its floor is made up of a muscular diaphragm composed of the mylohyoid muscles and a pair of geniohyoid muscles, above that diaphragm. The tongue is sometimes considered to also be part of the floor of the oral cavity, lying superior to the geniohyoid muscles.

Posteriorly, the oral cavity proper opens into the isthmus of fauces (oropharyngeal isthmus), a transitional space located between the oral cavity and oropharynx, bounded anteriorly by the palatoglossal arches and posteriorly by the palatopharyngeal arches. The space between these arches is called tonsillar fossa (sinus) and contains the palatine tonsils.

Watch the video below to learn more about each of the structures of the oral cavity.

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Take a look at our quiz below to test your knowledge about the structures of the oral cavity.

Take a step further with our custom quiz, which covers the oral cavity in even more detail. You can even personalize your own quiz to include the specific structures you would like to be questioned about.

Browse atlas

Browse our atlas gallery to look at each of the structures of the oral cavity in more detail.

Summary