The trigeminal nerve is the largest of the cerebral nerves and is the main sensory nerve of the oral maxillofacial region and the motor and proprioceptive nerve of the masticatory muscles. There are three branches, called the ophthalmic nerve, maxillary nerve and mandibular nerve, respectively.
The ophthalmic nerve is a sensory nerve that exits the skull via the superior orbital fissure and is mainly located in the lacrimal gland, eyeball, eyelid, forehead skin and part of the nasal mucosa.
2. The maxillary nerve is a sensory nerve, which can be divided into four segments according to its stroke: (1) cranial middle fossa segment: emits the middle meningeal nerve, which is distributed in the dura mater.
(2) Pterygopalatine fossa segment: emits zygomatic nerve, pterygopalatine nerve (including nasopalatine nerve and pre-palatine, mid-palatine and post-palatine nerves) and posterior superior alveolar nerve
(3) Infraorbital canal segment: the maxillary nerve enters the infraorbital fissure and is renamed the infraorbital nerve. It gives rise to the superior alveolar median nerve and the superior alveolar anterior nerve.
(4) Facial segment: the inferior lid branch, medial nasal branch, lateral nasal branch and superior labial branch emanate from the inferior orbital foramen.
The mandibular nerve is a mixed nerve and is the largest branch of the trigeminal nerve. It exits the skull through the foramen ovale and gives off the following branches: (1) Meningeal branch (sphenopalatine nerve): distributed in the dura mater.
(2) Internal pterygoid nerve: distributed in the internal pterygoid muscle.
(3) Deep temporal nerve: distributed in the temporalis muscle.
(4) Occipital nerve: distributed in the occipital muscle.
(5) External pterygoid nerve: distributed in the upper and lower heads of the external pterygoid muscle.
(6) Buccal nerve (buccal long nerve): distributed in the gingiva of the buccal side of the posterior mandibular teeth and the mucosal skin of the buccal area.
(7) Auriculotemporal nerve: mainly distributed in the temporomandibular joint, external auditory canal, parotid gland, and skin of temporal region.
(8) Lingual nerve: mainly distributed in the mandibular lingual gingiva, anterior 2/3 of the tongue and mucous membrane of the floor of the mouth, sublingual glands, etc.
(9) Inferior alveolar nerve: mainly distributed in the mandibular teeth and gingiva, mandibular hyoid muscle, anterior belly of bicuspid muscle, etc.