This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
When the ophthalmic division is affected the pain in neuralgia is over the brow and up toward the vertex of the skull; it also involves the eye. The points of exit of the supra-orbital branch at the supra-orbital foramen and of the nasal branch toward the lower portion of the nose are tender to pressure.
When the maxillary division is affected, there is pain in the cheek and ala of the nose. The tender points are the exit of the infra-orbital nerve at and below the infra-orbital foramen, at the exit of the malar branch on the malar bone, and the upper gums and hard palate.
When the mandibular division is affected the pain involves the lower jaw and the side of the head nearly to the top (auriculotemporal branch). The lower gums and tongue are also painful. Pain on pressure is felt over the mental foramen and in the course of the auriculotemporal nerve in front of and above the ear.