Trigeminal Nerve Branches
The trigeminal nerve (CN V) divides into three main branches: the ophthalmic division (V1), the maxillary division (V2), and the mandibular division (V3). 1
Primary Divisions
The trigeminal nerve is the largest cranial nerve and provides general sensation to the face, scalp, nasal cavity, oral cavity, and teeth, while also providing branchial motor innervation to the muscles of mastication. 1
Ophthalmic Division (V1)
- Exits through the superior orbital fissure and enters the orbit to provide sensory innervation to the upper face and forehead. 2, 3
- Innervates the globe, skin above the eye, and forehead region. 3
- This division is purely sensory and has no motor component. 3
Maxillary Division (V2)
- Exits the cranium through the foramen rotundum into the pterygopalatine fossa, then travels through the infraorbital canal and exits via the infraorbital foramen. 3
- Provides sensory innervation to the midface, including the cheek region, lower eyelid, side of nose, and upper lip. 2, 4
- Innervates the mucous membranes of the nasopharynx, maxillary sinus, soft palate, palatine tonsil, roof of the mouth, maxillary gingivae, and maxillary teeth. 4
- This division is also purely sensory. 3
Mandibular Division (V3)
- Exits through the foramen ovale and is the largest of the three divisions. 5, 6
- This is a mixed nerve containing both sensory (afferent) and motor (efferent) fibers, unlike V1 and V2 which are purely sensory. 5, 6
- Provides sensory innervation to the mandibular and temporal regions, skin of the lower jaw, tongue, and mucosal wall of the oral cavity. 2, 3
- Motor fibers innervate the muscles of mastication, mylohyoid, anterior digastric, tensor veli palatini, and tensor tympani muscles. 6
- Sensory axons enter the mandible to innervate the teeth and emerge from the mental foramen to innervate the skin of the lower jaw. 3
Additional Branch of Clinical Significance
Meningeal Branch (Nervus Spinosus)
- Originates from the mandibular nerve (V3) shortly after it exits the foramen ovale. 5
- Re-enters the cranium through the foramen spinosum to provide sensory innervation to the dura mater of the middle cranial fossa. 5
Clinical Imaging Considerations
- MRI is the preferred modality for investigating the entire trigeminal nerve course from the brainstem to peripheral branches. 1, 2
- CT remains essential for evaluating bony foramina (supraorbital, infraorbital, foramen ovale, foramen spinosum) and skull base anatomy. 2
- High-resolution MRI sequences can identify neurovascular compression, which is the most accepted theory for trigeminal neuralgia pathogenesis. 1
Common Clinical Pitfalls
- Perineural tumor spread can affect the trigeminal nerve anywhere along its course and should be considered in differential diagnosis. 1
- Cheek sensory deficits clearly indicate V2 involvement and warrant investigation of the infraorbital foramen, pterygopalatine fossa, and cavernous sinus. 2
- Multiple sclerosis can result in trigeminal neuralgia, necessitating brainstem imaging to look for demyelinating disease. 1