Corpus: Maxillary nerve

The maxillary nerve is the second terminal branch of the trigeminal nerve (cranial nerve V) and carries general sensory fibers. It also has some autonomic fibers attached along its course.

After leaving the trigeminal ganglion, the maxillary nerve runs forward in the lateral wall of the cavernous sinus. Before passing through the foramen rotundum, it gives off a meningeal branch for sensory supply to the meninges. In the pterygopalatine fossa, it divides into its terminal branches.

3.1. Meningeal branch (Ramus meningeus)

The meningeal branch provides sensory innervation to the dura mater.

3.2. Ganglionic branches (Rami ganglionares)

These branches run to the pterygopalatine ganglion and contain two types of fibers:

• sensory fibres that pass through the ganglion without synapsing,
• postganglionic autonomic fibres that synapse in the ganglion and then attach to the maxillary nerve or its branches.

The sensory fibres passing through the ganglion are sometimes also referred to as "indirect" maxillary branches. They include:

• Posterior superior nasal branches and nasopalatine nerve: These run through the sphenopalatine foramen and innervate large parts of the nasal mucosa and the mucosa of the ethmoidal air cells.
• Greater palatine nerve: This runs through the greater palatine foramen to the mucous membrane of the hard palate.
• Lesser palatine nerves: These pass through the lesser palatine foramina to the soft palate and the palatine tonsil.

Autonomic fibers are attached to the greater and lesser palatine nerves. These include parasympathetic fibers from the greater petrosal nerve (a branch of the facial nerve) and sympathetic fibers from the deep petrosal nerve, collectively referred to as the nerve of the pterygoid canal. They provide autonomic innervation to the salivary glands of the palatal mucosa.

3.3. Zygomatic nerve

The zygomatic nerve carries postganglionic fibers from the pterygopalatine ganglion to the lacrimal nerve, which innervates the lacrimal gland. Via a branch called the zygomaticofacial nerve, it supplies sensation to the skin above the zygomatic bone. The zygomaticotemporal nerve innervates the skin above the temporal bone.

3.4. Infraorbital nerve

The infraorbital nerve is the direct continuation of the main maxillary nerve trunk. It provides sensory innervation to the maxillary sinus and gives off three superior alveolar nerves (anterior, middle, and posterior), which together form the superior dental plexus that supplies the maxillary teeth. After passing through the infraorbital foramen, it releases superior labial and inferior palpebral branches, providing sensory innervation to the lower eyelid, upper lip, and the skin between these structures. It also sends fine external and internal nasal branches to the nose.