Trigeminal neuralgia: the electric shock mistaken for toothache

The trigeminal nerve is the fifth cranial nerve, which carries the sensations of touch and pain from the face to the brain. It has three branches: the first supplies the forehead and the area around the eye, the second the cheek, the upper lip, the upper jaw and the upper teeth, and the third the lower jaw, the lower lip and the lower teeth. The NHS writes that the pain of trigeminal neuralgia is felt in the teeth, the lower jaw, the upper jaw or the cheek, and less often in the forehead or the eye. A publication from the University of Göttingen also notes that the second and third branches are most often affected and that attacks are triggered by chewing and by touching the gums. When the pain's address is the teeth, the first door is the dentist's.

The character of the pain is decisive. The NHS describes the pain as sudden, severe, sharp and stabbing, often like an electric shock; the attacks last from a few seconds to about 2 minutes and stop as suddenly as they started. For the diagnosis, the international classification of headache disorders (ICHD-3) looks for attacks that stay on one side of the face within the area the nerve supplies, last from a fraction of a second to 2 minutes, are severe and are triggered by a stimulus that would not normally cause pain. The same classification also notes that after a painful attack there is usually a rest period during which the pain cannot be triggered.

The triggers are ordinary everyday movements. The NHS lists talking, smiling, chewing, brushing your teeth, washing your face, a light touch, shaving or putting on make-up, swallowing, kissing, a cool breeze or air conditioning, head movements and the vibration you feel when walking or in a vehicle; it adds that the pain can also come with no trigger at all. MSD Manuals writes that there may be a particular spot on the face, lip or tongue that starts an attack when touched (a trigger point), and that the pain is most often felt in the cheek beside the nose or in the jaw.

The course comes in waves. The NHS writes that attacks can come regularly for days, weeks or months, and in severe cases can repeat hundreds of times a day. The pain can disappear completely for months or years (remission), but these quiet periods tend to get shorter over time. In some people, a constant ache, throbbing or burning that accompanies the attacks also develops over time. This constant component can make the picture look even more like toothache.

The cause is usually not in a tooth but inside the skull. The NHS and MSD write that the most common cause is a blood vessel pressing on the nerve where it leaves the brain. Less often, multiple sclerosis (MS) or a tumour can damage the nerve. The European Academy of Neurology (EAN) guideline therefore divides the picture in two: primary trigeminal neuralgia, caused by a blood vessel pressing on the nerve (classical) or with no clear cause found (idiopathic), and secondary trigeminal neuralgia, caused by another disease rather than contact with a vessel. The guideline states that no clinical feature can rule out a secondary cause, so a brain MRI scan should be done during the diagnostic process.

The cost of going to the wrong address has been measured in published studies. In interviews with 51 patients in Germany who had interventional treatment for trigeminal neuralgia (a procedure through the skin or microvascular decompression), 41 of the patients (82 percent) had gone to a dentist first, and 27 of them had had invasive dental treatment, including extraction, root canal treatment and implants. Of 117 patients in India who had radiosurgery (gamma knife) and answered a survey, 55.5 percent had experienced their pain as toothache and 41.8 percent had had at least one dental procedure; after the procedure, 18.8 percent of patients reported that their pain got worse and 8.5 percent reported partial relief.

In a review of the records of 104 patients from Iraq, 88 patients had first been treated for a diagnosis of toothache, 55 had had teeth extracted, and in 92.7 percent of those who had extractions the pain did not improve at all. The authors also note that a large share of the extractions were done at the patient's request. At an orofacial pain centre in Thailand, 22.2 percent of 36 newly diagnosed patients had had teeth extracted before referral. These studies are retrospective; some rely on what patients remembered, and they come from centres that see severe cases. Even so, they all point the same way: extraction and root canal treatment do not cure trigeminal neuralgia.

Who gets it more often? The NHS writes that the condition is more common in women than in men, usually starts between the ages of 50–60 and is rare in adults under 40. If someone younger has similar attacks, the doctor looks more carefully for secondary causes such as MS. The NHS adds that it is very unlikely for trigeminal neuralgia to be the first symptom of MS.

The first list is signs that make it more likely the pain is coming from a tooth; for these, see your dentist. The signs in the second list point to pain from the nerve or to a situation that should not wait. The examination and tests make the distinction; these lists are so that you take the right information to the doctor.

There is no single test that shows trigeminal neuralgia. The diagnosis rests on the description of the pain; the tests are done to rule out a dental cause and secondary causes.

1. 1

   First, medicine safety and emergencies

   If a severe rash with redness, blisters or sores appears while you are taking carbamazepine, or if you have thoughts of harming yourself, the NHS says to get emergency help; in Türkiye, call 112 or go to A&E.

2. 2

   The dentist rules out the teeth

   The NHS writes that because the pain is felt in the jaw, the teeth and the gums, many patients go to a dentist first. The dentist looks for common causes such as infection or a cracked tooth with cold, tapping and bite tests and X-rays. If no tooth reproduces the pain, the right step is to note this clearly and refer you to a doctor.

3. 3

   A detailed history of the pain is taken

   The NHS writes that the GP asks how often the attacks come, how long they last and which area of the face they affect. Keeping notes on your attacks for a few days, recording how long they last, what triggers them and where they are, makes this consultation easier.

4. 4

   Similar conditions are ruled out

   The NHS lists jaw and tooth problems, cluster headache and nerve pain after shingles among the conditions to rule out; MSD adds sinus and jaw joint problems. The doctor identifies the painful areas by examining the head and jaw, and checks the sensation in the face.

5. 5

   Brain MRI scan

   Because no clinical feature can rule out a secondary cause, the EAN guideline recommends a high-resolution MRI scan during the diagnostic process. The NHS writes that an MRI scan can show sinusitis, tumours on the nerve, nerve damage caused by MS and a blood vessel pressing on the nerve. According to the guideline, seeing contact with a vessel does not confirm the diagnosis on its own, but it guides the decision about surgery.

6. 6

   Medicine and adjusting the dose

   The NHS writes that the first medicine is usually carbamazepine, started at a low dose and increased to an effective dose over a few days or weeks. A pharmacogenetic guideline published in the UK in 2026 recommends testing for the HLA genes that indicate the risk of an allergic skin reaction in everyone who is about to start carbamazepine or oxcarbazepine; ask your doctor whether this test is needed for you.

7. 7

   If medicine is not enough, referral to a specialist

   The NHS writes that if carbamazepine does not work, stops working over time or has too many side effects, you are referred to a neurology, neurosurgery or pain specialist. The EAN guideline asks for surgery to be offered when the pain cannot be controlled well enough with medicine or the medicine is not well tolerated.

Treating trigeminal neuralgia is not the dentist's field, but that of GPs, neurology, neurosurgery and pain specialists. The dentist's job is not to miss the diagnosis and to prevent unnecessary procedures. The medicine and the dose are decided by the doctor who follows you up.

Most of these mistakes come from the pain being so severe and from wanting something done as soon as possible. We are writing this so that you can ask the right questions whichever doctor you see.

Trigeminal neuralgia is often a long-term condition, but the NHS writes that the treatments available help most patients to some extent. The sequence below is a summary of the usual course; the plan of the doctor who follows you up comes first.

1. The first days and weeks of the medicine

   The dose is increased gradually over a few days or weeks. During this period, side effects such as drowsiness and dizziness may be more noticeable; check with your doctor before driving.

2. The pain coming under control

   The medicine is continued regularly until the pain improves noticeably or goes away; the NHS writes that this can take years.

3. Remission

   The pain may disappear for months or years. If the medicine needs to be reduced, this is done slowly over days or weeks according to the doctor's plan. The quiet periods may get shorter over time.

4. The pain coming back

   The NHS writes that carbamazepine can stop working over time. In this situation, you are referred to a specialist for other medicines or interventional options; if one procedure does not work, another can be tried.

We do not give a single figure here, because treating trigeminal neuralgia is not the dentist's field but that of neurology and neurosurgery, and its scope varies greatly from person to person. These are the items that determine the scope:

When the diagnosis is made

When nerve pain is considered early, unnecessary extractions, root canal treatment and the work to restore the teeth that follows are avoided.

Imaging

A brain MRI scan is done during the diagnostic process; additional sections are requested if needed.

Medicine and blood monitoring

Long-term use of medicine may require follow-up appointments to adjust the dose and, when needed, blood tests.

Whether interventional treatment is needed

Procedures through the skin, radiosurgery and open surgery differ greatly in scope, length of hospital stay and follow-up.