Blood and nerve supply of the oral cavity

The oral cavity or mouth, though quite small, is supplied by a dense network of nerves and blood vessels.

The nerve supply comes from the branches of six cranial nerves, namely - the trigeminal nerve, facial nerve, glossopharyngeal nerve, vagus nerve, and the hypoglossal nerve, whereas the blood supply comes from the branches of the external carotid artery and the veins drain into the internal and external jugular veins.

First off, let's start with the arteries.

The arterial supply comes from the external carotid artery branches - the lingual artery, facial artery, and the maxillary artery.

The lingual artery is the second branch of the external carotid artery and arises at the level of the greater cornu of the hyoid bone.

It runs upwards and medially till it reaches the greater cornu and then dips downwards, beneath the posterior belly of digastric and stylohyoid muscles, creating a loop over the hypoglossal nerve.

The lingual artery then ascends almost vertically upwards to reach the tongue's inferior surface and continues as its terminal branch, the deep lingual artery, which supplies the anterior two-thirds of the tongue.

The lingual artery gives off four branches: the suprahyoid artery, the dorsal lingual artery, the deep lingual artery, and the sublingual artery.

The suprahyoid artery runs along the hyoid bone and supplies the omohyoid, sternothyroid, and thyrohyoid muscles.

The dorsal lingual artery supplies the posterior one-third of the tongue, soft palate, palatoglossal fold, lingual tonsil, epiglottis.

The deep lingual artery supplies the tongue’s ventral surface.

The sublingual artery supplies the sublingual salivary gland, the genioglossus, geniohyoid and mylohyoid muscles, and the mandible.

Second, the facial artery arises from the external carotid artery at the level of the angle of the mandible, just above the lingual artery.

It then takes an S-shaped course deep to the posterior belly of digastric and stylohyoid muscles - and crosses the mandible just anterior to the masseter muscle at a depression in the mandible termed the antegonial notch.

Then the artery continues across the cheek to the angle of the mouth, giving rise to the superior and inferior labial arteries.

The artery passes upwards along the side of the nose, giving rise to the lateral nasal artery.

It then continues on the side of the nose as the angular artery and ends at the medial commissure of the eye.

It gives off some branches to the oral cavity, including the ascending palatine artery to the soft palate; the tonsillar artery to the palatine tonsils; the submental artery to the chin and the mylohyoid muscle.

The glandular branches of the facial artery also supply the submandibular salivary gland.

Third, the maxillary artery, which is the largest terminal branch of the external carotid artery and supplies deep structures of the face including the mandible, pterygoid, infratemporal fossa and segments of the pterygopalatine fossa.

It arises posteriorly to the condylar neck of the mandible within the parotid gland, it then exits the parotid gland and passes anteriorly between the ramus of the mandible and the sphenomandibular ligament within the infratemporal fossa.

As it passes through the infratemporal fossa the maxillary artery can be divided in 3 parts: 1st part the mandibular part, 2nd the pterygoid part and 3rd the pterygopalatine part.

The mandibular part aka the bony part or 1st part runs medially to the neck of the mandible and passes on the inferior border of the lateral pterygoid muscle and gives off the inferior alveolar artery.

The inferior alveolar artery descends inferiorly following the inferior alveolar nerve and gives off a lingual and a mylohyoid branch.

The small lingual branch supplies the lingual mucous membrane while the mylohyoid branch supplies the mylohyoid muscle.

Then the inferior alveolar artery runs through the mandibular foramen to enter the mandibular canal, supplying the mandible and lower molars and premolars.

Near the first premolar, the inferior alveolar artery divides into two terminal branches the incisive branch, which supplies the incisor and canine teeth and the mental branch supplying the chin

Next, the pterygoid part aka the muscular part or 2nd part, this portion runs between the temporalis and lateral pterygoid and gives branches to the muscles of mastication, the masseteric artery to the masseter muscle, the deep temporal arteries to the temporalis muscle; and the pterygoid branches to the medial and lateral pterygoid muscles.

Another branch, the buccal artery, supplies buccinator muscle, the buccal mucosa and the skin.

Finally, the pterygopalatine part or 3rd part: This portion passes from the infratemporal fossa into the pterygopalatine fossa via the pterygomaxillary fissure.

It gives off the descending palatine, posterior superior alveolar artery, and the infraorbital artery.

The descending palatine splits into two branches the greater palatine artery that goes to supply the hard palate and the lesser palatine branches that supply the soft palate and palatine tonsil.

The posterior superior alveolar artery further divides into two or three branches, which bore through the body of the maxilla and supply premolar and molar teeth, the maxillary sinus and associated gingiva.

The infraorbital artery gives two branches to the oral cavity — the middle superior alveolar artery to the upper premolar teeth, and the anterior superior alveolar artery to the maxillary air sinus, and the upper canine and incisor teeth.

Moving on, the veins of the oral cavity accompany the arteries of the same name and eventually drain into the internal and external jugular veins.

Some of the veins though, take a slight detour and join into the pterygoid plexus, which is a cluster of veins located in the skull's infratemporal fossa.

These include the greater and lesser palatine veins and the sphenopalatine veins from the palate; the superior and inferior alveolar veins from the teeth and gingiva, and veins from the muscles of mastication.