Anatomy of Maxillary and Mandibular Nerves

Study Notes

The fifth cranial nerve, trigeminal, consists of large sensory and small motor roots, making it a mixed nerve.
The sensory root contains a trigeminal ganglion and has three main branches:
- Ophthalmic nerve (CN V1)
- Maxillary nerve (CN V2)
- Mandibular nerve (CN V3)

Origin: Second division of the trigeminal nerve, pure sensory; arises from the trigeminal ganglion in the middle cranial fossa.
Course:
- Travels forward in the lateral wall of the cavernous sinus.
- Passes through the foramen rotundum into the pterygopalatine fossa.
- Continues through the pterygomaxillary fissure into the infratemporal fossa and through the inferior orbital fissure into the orbit as the infraorbital nerve.
Termination: Infraorbital nerve runs forward on the orbital floor, exiting via the infraorbital foramen to supply sensation to the face.

In the cranial cavity:
- Meningeal branch supplies dura mater of the middle cranial fossa.
In the pterygopalatine fossa:
- Ganglionic branches provide roots to the pterygopalatine ganglion.
In the infratemporal fossa:
- Zygomatic nerve: Enters the orbit and divides into zygomaticofacial and zygomaticotemporal branches for the face and temporal fossa.
- Posterior superior alveolar nerve: Supplies upper molar teeth through the maxilla.
Branches of the infraorbital nerve:
- Middle superior alveolar nerve: Supplies upper two premolars.
- Anterior superior alveolar nerve: Supplies canine and incisors.
- Facial branches:
  - Palpebral branch: Lower eyelid.
  - Nasal branch: Side of the nose.
  - Labial branch: Upper lip.

Origin: Third division of the trigeminal nerve, formed by a large sensory root and a small motor root.
Course:
- Both roots leave the cranial cavity through the foramen ovale, uniting to form the main trunk which descends in the infratemporal fossa.
Termination: Divides into anterior (smaller) and posterior (larger) divisions beneath the lateral pterygoid muscle.

From the trunk:
- Nervus spinosus: Enters cranial cavity, supplies dura mater.
- Nerve to medial pterygoid: Supplies medial pterygoid muscle, tensor palati, and tensor tympani.
From the anterior division:
- Nerve to lateral pterygoid: Supplies lateral pterygoid muscles.
- Deep temporal nerves: Supplies temporalis muscle.
- Nerve to masseter: Supplies masseter muscle.
- Buccal nerve: Sensory nerve supplying skin and mucous membrane of the cheek.
From the posterior division:
- Auriculo-temporal nerve: Supplies sensory to the temporal region, auricle, external auditory canal, and parotid gland; carries autonomic fibers to parotid gland.
- Lingual nerve: Provides sensation to anterior 2/3 of the tongue and floor of mouth; joins with chorda tympani for taste sensation.
- Inferior alveolar nerve: Supplies lower jaw teeth, enters mandibular foramen, and branches into incisive and mental nerves.

Courses: Descends to the mandibular foramen and travels in the mandibular canal.
Mylohyoid branch: Supplies mylohyoid muscle and anterior digastric muscle.
Dental branches: Supply molar and premolar teeth posterior to the canine.