Nerve · Head

Trigeminal nerve

Nervus trigeminus

The trigeminal is the great sensory nerve of the face and the motor nerve of chewing. It leaves the side of the pons, swells into the trigeminal ganglion, and splits into three divisions that between them carry sensation from almost the whole face: ophthalmic (V1) to the forehead and scalp, maxillary (V2) to the cheek and upper teeth, and mandibular (V3) to the lower face, jaw and front of the tongue. Only the third division carries motor fibres, and those drive the muscles that close the jaw — masseter, temporalis and the pterygoids — which is why jaw and facial-pain problems so often travel together.