Teeth grinding and headaches: how they're linked, and what the research can't tell you

Dr. Malek Sleem

Licensed Physical Therapist · FixUrMotion, Beirut

Ask most people why they wake with a headache and a sore jaw, and they will say they grind their teeth. It is a reasonable guess, and quite often only part of the answer.

Grinding and clenching are genuinely linked with headache, but the link is weaker and messier than the usual story. This article covers what the studies found, where they fall short, and how to tell whether your headache has a jaw share. For the basics of night grinding, start with our guide to teeth grinding at night.

What the research actually shows

A 2014 systematic review in Headache screened 449 papers for studies that diagnosed both sleep bruxism and headache properly. Only two qualified, both in adults, and in both, people who ground at night had roughly three to four times the odds of headache (odds ratios of 3.12 and 3.8).

A 2021 update took in five studies and split bruxism into its two kinds. Awake bruxism, the clenching and bracing you do by day, came with about five times the odds of tension-type headache (an odds ratio of 5.23). Sleep bruxism showed no association with tension-type headache. For migraine the results were mixed, and the authors called the link controversial. They rated the certainty of all of it low to very low.

So the habit most clearly tied to headache is the one you do awake, and even that rests on a handful of studies.

What the research does not show

Three gaps change how you should read your own situation.

• An association is not a cause. These studies found grinding and headache in the same people, not that one produces the other. Pain could make people brace, or both could share a driver. In a survey of 18,980 people in five European countries, chronic morning headache affected 7.6%, and its strongest links were with anxiety, depression and insomnia. Stress and anxiety also turn up daytime clenching.
• "I grind" is not the same as grinding. In a New York sleep-lab study, 55.3% of 124 women with chronic jaw-muscle pain said they ground at night, against 15.2% of 46 women without it. Two nights of recording found grinding in 9.7% and 10.9%: no different. People in pain were far more likely to say they ground, without grinding more.
• More grinding is not more pain. In a Montreal study that recorded 100 people diagnosed with sleep bruxism, it was the lower-frequency grinders, not the heaviest, who were more likely to report jaw-muscle pain and fatigue.

So a confident "it's your grinding", made without an examination, is a guess.

How a jaw produces a headache

Your main chewing muscles are the temporalis, the fan over the temple that bulges when you clench, and the masseter at the angle of the jaw. Overworked and sensitised, they are felt at the temples, in front of the ears and along the jaw.

Sustained, low-level effort may matter more than dramatic grinding. In a classic Copenhagen experiment, people clenched gently, at about a tenth of their maximum, for 30 minutes. Within 24 hours, 69% of 58 people with tension-type headache developed a tension-type headache, against 17% of 30 people without the condition. That looks more like a day of bracing at a screen than a night of grinding, and it hit hardest in people already prone to headache.

The International Classification of Headache Disorders (ICHD-3) lists this as its own diagnosis, 11.7: headache attributed to temporomandibular disorder (TMD, the umbrella term for jaw-joint and jaw-muscle problems). It needs a painful jaw problem plus at least two signs of a link: the headache began with it; jaw movement, chewing, clenching or grinding aggravates it; or pressing the temple muscle or moving the jaw brings it on in an examination. When the jaw diagnosis is uncertain, ICHD-3 says to code the headache as tension-type, which is how a jaw share can sit inside a "tension headache" label for years.

Then there is the wiring. The trigeminal nerve, which supplies the jaw and the temple, and the nerves from the top of the neck feed the same brainstem relay, the trigeminocervical complex. As one review sets out, signals converge on the same neurones there, and those neurones can become sensitised, so pain spreads and is felt away from its source. The jaw and the upper neck converge on one system, and their inputs can add up. Neither has to be causing the other for both to matter.

Does your headache have a jaw share?

These lean towards the jaw. None is proof alone; a pattern is what counts.

1. Where it sits. Temples, in front of the ears, or over the angle of the jaw, often on both sides.
2. How your jaw feels on waking. Tired, stiff or sore, easing as the morning goes on.
3. What makes it worse. Gum, tough food, long conversations, stressful days with your jaw set.
4. What pressing does. Clench to find the temple muscle, relax, then press it firmly for a few seconds. Repeat over the masseter, both sides. Tenderness alone means little; what counts is pressure bringing on your familiar headache.
5. Clicking. It supports a jaw problem, but on its own it says little about your headache.

The best validation work backs the last two points. In a study of 373 people with temple headaches and a painful jaw disorder, the expert reference standard judged the jaw responsible for the headache in only 170 of them. Two features together identified those cases with 89% sensitivity and 87% specificity: a temple headache that changes with jaw movement, chewing or clenching, and that headache being brought on by pressing the temple muscle or moving the jaw. Jaw-joint scans added no accuracy.

A jaw share also often comes with a neck share. In a small trial of 43 people with headaches from the neck, 44.1% also had a jaw disorder. If yours starts at the base of the skull, read is my headache coming from my neck?

What helps, and how good the evidence is

Each option has a place. None has strong evidence for reducing headaches.

The guard. It protects enamel well, so keep wearing yours. As a pain treatment it is weaker. A UK review of 52 trials found no evidence that splints reduced jaw-disorder pain against no or minimal treatment, on very low-quality evidence. In a trial of women with both migraine and a painful jaw-muscle disorder, migraine medication plus a splint did best on most headache measures, though on the main one, headache days, the difference held only among those who completed treatment. The authors concluded that migraine improved significantly only when both conditions were treated. More in our night guard article.

The daytime habit. Awake clenching is most tied to headache, so it is the obvious target: lips together, teeth apart, tongue resting on the roof of the mouth, and random checks through the day. No trial has tested this as a headache treatment; the logic comes from the association. The method: how to stop clenching your jaw.

Physiotherapy for the jaw and the neck. A meta-analysis of 48 trials rated the evidence for exercise and manual therapy in jaw disorders as low, while finding manual therapy at the jaw or the neck promising. In the trial of 43 people above, adding jaw treatment to neck treatment reduced headache intensity, still at six months, which the neck-only group did not show. One small trial is a signal, not a settled answer.

Stress and sleep. Stress feeds the daytime habit. If loud snoring, gasping or unrefreshing sleep is part of your nights, see your doctor first: sleep apnoea is a separate driver of morning headache, covered in our article on night grinding.

What to do this week

• Keep a two-week log. Each morning: a jaw score from 0 to 10, headache yes or no, and where it sat.
• Run the pressure check on your temple and jaw muscles, both sides.
• Start the daytime checks. Random reminders, the resting position, a slow release.
• Keep your guard, and see your dentist about cracked teeth or fillings.
• Check your neck. Sitting tall, turn your head slowly right, then left. A clear difference between sides is worth having examined.

If your headaches sit at the temples, change with chewing or clenching, and nobody has examined your jaw and upper neck together, that is worth one short call, online by video or in person in Beirut.

Frequently asked questions

Dr. Malek Sleem

Licensed physical therapist and founder of FixUrMotion in Beirut, Lebanon. Helping people move better, recover faster, and live pain-free, in-clinic and at home.

This article is general information, not a diagnosis. Headaches and jaw pain have causes that range from harmless to urgent; if anything in the list above applies to you, see a doctor or dentist first. Nothing here is a reason to stop wearing an appliance your dentist made, or to start, stop or change a medication, without speaking to the clinician responsible for it.

Is your jaw part of your headache?

If your headaches sit at the temples, change with chewing or clenching, and nobody has examined your jaw and upper neck together, that is worth one short call. We'll tell you honestly whether there is a jaw or neck share worth working on, and if there isn't, who you should see instead.

Not ready for a call? Take the Headache Check, see where yours starts on the Headache Map, or run the Source Test: three checks, about three minutes.