Boundaries :
- Ventrally : lips
- Laterally : cheeks
- Floor : oral diaphragm
- Roof : palate
- Dorsally : continuous with the pharanyx
- The dental arches divide the oral cavity into the:
- 1. the oral vestibule
- 2. the oral cavity proper
The oral cavity proper
Borders:
- Anterior and lateral:
- Alveolar processes
- Gum
- Superior border : (concave)
- Hard palate
- Soft palate
- Inferior border :
- Tongue
- Mylohyoid m., Ant. belly of digastric m., Geniohyoid m.
- Posterior border: Continuous into the pharynx through oropharyngeal isthmus.
The oral vestibule:
- External borders :
- lips : 2 fleshy folds surrounding the oral orifice they accommodate orbicularis oris muscle. they contain nerves, vessels & glands.
- cheeks : they are continuous with lips at nasolabial grooves.
- Their muscle is buccinator
- Internally they are lined by mucos membrane.
- Externally they are covered by skin, buccal pad of fat, and buccopharyngeal fascia
- Internal borders:
- Teeth
- Gums
The vestibule contains the following:
- 1 - Opening of the parotid duct.
- 2 - Superior labia frenulum
- connect sup. lip to the gum
- 3. Inferior labia frenulum.
- 4. Maxillary tuberosity
- 5. Fornix