The gingivae are supplied by multiple vessels and the source depends on which side of each tooth the gingiva is—the side facing the oral vestibule or cheek (vestibular or buccal side), or the side facing the tongue or palate (lingual or palatal side):
Buccal gingiva of the lower teeth is supplied by branches from the inferior alveolar artery, whereas the lingual side is supplied by branches from the lingual artery of the tongue.
Buccal gingiva of the upper teeth is supplied by branches of the anterior and posterior superior alveolar arteries.
Palatal gingiva is supplied by branches from the nasopalatine (incisor and canine teeth) and greater palatine (premolar and molar teeth) arteries.
Veins from the upper and lower teeth generally follow the arteries (Fig. 8.279).
Inferior alveolar veins from the lower teeth, and superior alveolar veins from the upper teeth drain mainly into the pterygoid plexus of veins in the infratemporal fossa, although some drainage from the anterior teeth may be via tributaries of the facial vein.
The pterygoid plexus drains mainly into the maxillary vein and ultimately into the retromandibular vein and jugular system of veins. In addition, small communicating vessels pass superiorly, from the plexus, and pass through small emissary foramina in the base of the skull to connect with the cavernous sinus in the cranial cavity. Infection originating in the teeth can track into the cranial cavity through these small emissary veins.
Venous drainage from the teeth can also be via vessels that pass through the mental foramen to connect with the facial vein.
Veins from the gingivae also follow the arteries and ultimately drain into the facial vein or into the pterygoid plexus of veins.
Lymphatic vessels from the teeth and gingivae drain mainly into submandibular, submental, and deep cervical nodes (Fig. 8.280).
All nerves that innervate the teeth and gingivae are branches of the trigeminal nerve [V] (Figs. 8.281 and 8.282).
The lower teeth are all innervated by branches from the inferior alveolar nerve, which originates in the infratemporal fossa from the mandibular nerve [V3] (Figs. 8.281 and 8.282). The inferior alveolar nerve and its accompanying vessels enter the mandibular foramen on the medial surface of the ramus of the mandible and travel anteriorly through the bone in the mandibular canal. Branches to the back teeth originate directly from the inferior alveolar nerve.
Adjacent to the first premolar tooth, the inferior alveolar nerve divides into incisive and mental branches:
The incisive branch innervates the first premolar, the canine, and the incisor teeth, together with the associated vestibular (buccal) gingiva.
The mental nerve exits the mandible through the mental foramen and innervates the chin and lower lip.
Anterior, middle, and posterior superior
All upper teeth are innervated by the anterior, middle, and posterior superior alveolar nerves, which originate directly or indirectly from the maxillary nerve [V2] (Figs. 8.281 and 8.282).
The posterior superior alveolar nerve originates directly from the maxillary nerve [V2] in the pterygopalatine fossa, exits the pterygopalatine fossa through the pterygomaxillary fissure, and descends on the posterolateral surface of the maxilla. It enters the maxilla through a small foramen approximately midway between the pterygomaxillary fissure and the last molar tooth, and passes through the bone in the wall of the maxillary sinus. The posterior superior alveolar nerve then innervates the molar teeth through the superior alveolar plexus formed by the posterior, middle, and anterior alveolar nerves.