V2 supplies the side of the face from the ear to below the eye, the side of the nose, the upper lip, upper gums and teeth.
V3 is the most common site of TN and the pain runs along the jaw, lower lip, lower gums and teeth. Sometimes V2 and V3 are both affected.
TN often has a specific trigger which sets the pain off. This can be stimtulation of the lip, nostril, cheek, opr by activities such as chewing, or swallowing.