What is it?
The trigeminal nerve is the sensory nerve of the face. It has three branches: the forehead and the area around the eye, the cheek and upper jaw, and the lower jaw and lower lip. In trigeminal neuralgia the firing threshold of this nerve drops, so even a touch that would not normally hurt is felt as severe pain.
The pain has a description all of its own. It is one-sided, starts abruptly, lasts from a few seconds up to two minutes and can return many times in the same day. Washing your face, brushing your teeth, talking, chewing or cold air can set it off. Between attacks the face is most of the time completely quiet.
It is confused with toothache because the pain is often felt along the line of the upper or lower jaw teeth. Pain coming from a tooth, though, is linked to heat and cold, lasts for minutes and throbs. Neuralgia pain is triggered by touch, is short and sharp, and X-rays show nothing that would explain it.
Signs
You will not necessarily have all of these at once.
Why does it happen?
- 01
Pressure from a blood vessel next to the nerve
The mechanism shown most often is a blood vessel resting against the nerve where it leaves the brainstem. Over the years the insulating sheath of the nerve thins and signals begin to travel without control.
- 02
Conditions that affect the nerve sheath
Conditions that damage the myelin sheath can cause the same pain. When the pain starts at a young age or affects both sides, this possibility is looked into particularly closely during neurological assessment.
- 03
Structural causes along the path of the nerve
Rarely, a growth or an anatomical abnormality along the course of the nerve produces this picture. That is why imaging is requested; treatment is not decided on until these causes have been ruled out.
- 04
Triggers are not the cause of the condition
Wind, an iced drink, putting on make-up or brushing start an attack, but they do not create the condition. People most of the time take them for the cause and set off on the wrong search.
How does it progress?
- Type 1
The classic form, coming in attacks
There are only short, severe attacks. Between attacks there is no pain and the face feels normal. This is the form seen most often.
- Type 2
A dull background pain as well
Alongside the short attacks there is a burning or dull pain that carries on through the day. This form is generally harder to treat.
- Secondary
A form caused by another condition
The pain comes with numbness in the face, a change in hearing or other neurological findings. In this picture the underlying cause is looked for.
- Course
Quiet spells and change over time
The condition can produce quiet spells lasting months. Over the years, quiet spells growing shorter and attacks becoming more frequent is a commonly reported course.
How is it treated?
Diagnosing and treating this condition belongs to neurology. The dentist's job here is to find out whether the pain is coming from a tooth, by examination and by X-rays where needed, and to stop any irreversible procedure if there is no dental cause. Root canal treatment or extraction of a healthy tooth does not take this pain away.
In neurology the diagnosis rests largely on your history; how long the pain lasts, what triggers it and where it spreads are the deciding points. An MRI scan may be requested to look for secondary causes. The first step is medication, and ordinary painkillers are most of the time not enough for this pain; the choice of drug, the dose and the follow-up are the doctor's decision.
When medication is not enough, or cannot be continued because of side effects, interventional methods and surgical options are considered together with neurosurgery. None of these treatments is carried out in a dental clinic; our role is to recognise the picture, rule out dental causes and refer you to the right department.
- Lasting numbness of the face, double vision or hearing loss appearing alongside the pain
- Pain that affects both sides, or that starts at a young age
- A rash, fever, extreme drowsiness or loss of balance developing while you are taking medication
- Being unable to eat or drink, and unable to take fluids, because of the pain
How is it prevented?
- Do not let a healthy tooth be treated before a diagnosis is made; if the pain is not coming from a tooth, extraction and root canal treatment will not change the outcome.
- Write down which spot sets the pain off when touched, how many seconds it lasts and how many times a day it comes; this record is what helps most in a neurological assessment.
- While you are having attacks, cut down on known triggers such as cold wind, iced drinks and hard brushing.
- Do not give up your mouth care; stopping brushing for fear of pain soon adds decay and gum problems.
Frequently asked questions
- Will the pain go if the tooth is taken out?
- If the tooth is not the source of the pain, it is not expected to go. Some people describe brief relief after an extraction, but the pain most of the time comes back in the same area. This is why it is first investigated whether there is a dental cause, and if there is none, no procedure is carried out.
- The pain has been gone for a while, has the condition passed?
- Trigeminal neuralgia can produce quiet spells lasting months. The pain stopping does not on its own mean you have recovered. Do not change treatment decisions by yourself during this time, and if you are taking medication, ask your doctor before you stop it.
- Which specialist should I see?
- The assessment is done by neurology. Coming to a dentist first is not wrong; it needs to be established whether the pain is coming from a tooth. But when no dental cause is found, the next step is a neurology examination.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.