Anatomy of the Mouth

Anatomy of the Mouth

The mouth is a vital part of the digestive system, responsible for receiving food, chewing and mixing it before swallowing. The mouth is made up of two main parts: the oral vestibule and the oral cavity proper.

The oral vestibule is the front part of the oral cavity, located between the dental arch and the lips/cheeks. It is bounded by:

• Upper and lower lips: Two fleshy folds surrounding the oral fissure, composed of skin, mucosa, orbicularis oris muscle, blood vessels, labial nerves, fatty fibrous tissue and small salivary glands.

• Philtrum: The vertical groove between the skin of the upper lip.

• Labial frenulum: The mucosal fold connecting the lip to the gingiva.

• Cheeks: The sides of the mouth, composed of skin, skeletal muscle (buccinator muscle, zygomaticus major muscle, risorius muscle, platysma muscle), buccal fat pad and mucosa. The parotid duct opens opposite the upper second molar.

The oral cavity proper lies behind the dental arch, bounded by:

• Dental arch, teeth and gingiva: Bounding the anterior and lateral aspects of the oral cavity.

• Pharyngeal isthmus: The connection to the pharynx.

• Hard and soft palate: Forming the roof of the oral cavity.

• Lingual mucosa + inner surface of the mandible: Forming the floor of the oral cavity.

Inside the oral cavity proper, we can observe the following structures:

• Lingual frenulum: The mucosal fold connecting the floor of the mouth to the underside of the tongue.

• 2 sublingual caruncles: Located on either side of the lingual frenulum, where the submandibular ducts open.

• Tongue: An important organ in chewing, swallowing and speech.

• Gingiva: The soft tissue covering the dental arches, composed of fibrous tissue and covered by stratified squamous epithelium. The gingiva has two parts: the free gingiva surrounding the neck of the tooth and the attached gingiva firmly attached to the dental arch.

• Gingival papilla: The elevated part of the mucosa on the surface of the vestibule gingiva.

• Palate:

• Hard palate: Formed by the palatine process of the maxilla and the horizontal plate of the palatine bone.

• Soft palate: Mobile soft tissue attached to the posterior margin of the hard palate, extending downwards and backwards.

• Uvula: The end of the soft palate, projecting downwards.

• 2 palatoglossal and palatopharyngeal arches: Bounding the tonsillar fossa containing the palatine tonsil.

Salivary glands play a crucial role in secreting saliva, which helps to moisten the mouth, digest food and protect teeth from decay. There are two types of salivary glands:

• Major salivary glands: These include the parotid gland, submandibular gland and sublingual gland.

• Minor salivary glands: These are scattered throughout the lips, cheeks, palate and tongue.