Anatomy of Maxillary and Mandibular Nerves

Overview of Cranial Nerve V (Trigeminal Nerve)

• 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)

Anatomy of the Maxillary Nerve (CN V2)

• 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.

Branches of the Maxillary Nerve

• 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.

Anatomy of the Mandibular Nerve (CN V3)

• 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.

Branches of the Mandibular Nerve

• 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.

Inferior Alveolar Nerve Details

• 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.