Sensory Distribution of V1-V3 Trigeminal Nerve Branches
The trigeminal nerve divides into three distinct sensory branches: V1 (ophthalmic) innervates the upper face and forehead, V2 (maxillary) innervates the midface and cheek, and V3 (mandibular) innervates the lower face including mandibular and temporal regions. 1
V1 (Ophthalmic Division) - Upper Face
- V1 exits via the supraorbital foramen and provides sensory innervation to the upper face and forehead 1
- This division supplies sensation to the eyebrow, upper eyelids, cornea, ciliary body, iris, lacrimal gland, conjunctiva, and portions of the nasal cavity 2
- V1 also innervates the skin of the forehead and nose, as well as intracranial structures including the tentorium cerebelli and portions of the dura mater 2
- V1 is the smallest of the three divisions and is purely sensory in function 2
V2 (Maxillary Division) - Midface
- V2 originates from the infraorbital foramen and innervates the midface, including the cheek region 1
- This division exits the cranium through the foramen rotundum into the pterygopalatine fossa, then travels through the infraorbital canal before emerging at the infraorbital foramen 3
- V2 provides sensation to the skin below the eye and above the mouth 3
- Cheek sensory deficits clearly indicate V2 involvement and warrant investigation of the infraorbital foramen, pterygopalatine fossa, and cavernous sinus 1
V3 (Mandibular Division) - Lower Face
- V3 innervates the mandibular and temporal regions 1
- This is the largest division and contains both sensory and motor fibers, exiting through the foramen ovale 4
- V3 provides sensory innervation to the skin of the lower jaw, tongue, oral mucosa, and teeth within the mandible 3
- The motor component innervates the muscles of mastication 4, 5
- Tragus sensory changes should prompt consideration of both V3 mandibular nerve pathology and cervical nerve involvement, depending on the precise distribution pattern 1
Clinical Pitfalls
- When evaluating trigeminal neuropathy, imaging must cover the entire course of the nerve from brainstem to peripheral branches 1
- MRI is the preferred imaging modality for investigating trigeminal nerve pathology 1
- Perineural tumor spread can affect the trigeminal nerve anywhere along its course and must be considered in the differential diagnosis 5