Sybil,
When I was going through the Trigeminal pain, I was researching like crazy and found this online to help describe it. It fit me to a 'T'. It's actually a write up about Trigeminal Neuralgia (another disorder) but since both are caused by an irritation to the Trigeminal nerve, the outcome is the same:
The trigeminal nerve (also called the fifth cranial nerve) is one of the main nerves of the face. There is one on each side. It comes through the skull from the brain in front of the ear. It is called trigeminal as it splits into three main branches. Each branch divides into many smaller nerves.
The branches of the trigeminal nerve take sensations of touch and pain to the brain from your face, teeth and mouth. The trigeminal nerve also controls the muscles used in chewing, and the production of saliva and tears.
Neuralgia means pain coming from a nerve. In TN you have sudden pains that come from one or more branches of the trigeminal nerve. The pains are usually severe. The second and third branches are the most commonly affected. Therefore, the pain is usually around your cheek or jaw or both. The first branch is less commonly affected so pain over your forehead and around your eye is less common. TN usually affects one side of your face. Rarely, both sides are affected.
The pain is stabbing ("like electric shocks"), piercing, sharp, or knife like. It usually lasts a few seconds but can last up to two minutes. The pain can be so sudden and severe that you may jerk or grimace with pain. The time between each pain may be minutes, hours, or days. Sometimes several pains repeat in quick succession. After an attack of pain you may have a dull ache and tenderness over the affected area which soon eases. However, constant pain in the face is not usually a feature of TN.
You may have 'trigger points' on your face where touch or even a draught of air can trigger a pain. These are often around the nose and mouth. Because of these, some people do not wash or shave for fear of triggering a pain. Eating, talking, smoking, brushing teeth, or swallowing may also trigger a pain. Between attacks of pain, there are usually no other symptoms, the nerve works normally, and a doctor's examination would find no abnormality.