Teeth Grinding at Night: Why It's So Hard to Stop

A sore jaw most mornings. A partner who mentions a grinding sound in the middle of the night that you have no memory of. An earache that sends you to check for an ear infection that turns out not to be there. Teeth grinding has a habit of showing up sideways, as a cluster of unrelated-seeming complaints, before anyone connects them to the jaw.

This article covers what causes teeth grinding, why the nighttime version is specifically harder to deal with than clenching you do while awake, the symptoms and complications MedlinePlus lists, what actually helps, and where it overlaps with sleep apnea.

What bruxism actually is

MedlinePlus defines bruxism simply: it's when you grind your teeth, sliding them back and forth over each other. People can clench or grind without being aware of it, and it can happen during the day or at night. Some people probably clench or grind their teeth and never feel any symptoms from it at all — whether it causes pain varies a lot from person to person.

What causes it

MedlinePlus is upfront that there is some disagreement about the cause of bruxism, though daily stress may be the trigger in many people. Beyond stress, several factors influence whether grinding ends up causing pain and other problems: how long and how tightly you clench and grind, whether your teeth are misaligned, your posture, your ability to relax, your diet, and your sleeping habits.

The National Institute of Dental and Craniofacial Research (NIDCR) adds a few specific factors to that list: psychosocial factors like stress, mood and nervousness; a person's genes; consuming alcohol or caffeine; smoking; and certain medications used to treat depression, seizures and ADHD, which it says may increase the chances of having bruxism. None of this points to a single cause — it's a condition with several contributing factors that vary from one man to the next, not one trigger with one fix.

Why nighttime grinding is the harder problem

This is the detail that makes bruxism different from most habits: MedlinePlus states plainly that grinding during sleep is often a bigger problem specifically because it is harder to control. You can't catch yourself mid-grind the way you might catch yourself clenching your jaw at a stressful moment during the day. NIDCR adds an interesting wrinkle to this: awake bruxism is actually the more common of the two, but sleep bruxism is the one that has been studied more — researchers have focused more attention on the version people have the least ability to consciously notice or interrupt.

That distinction carries through to treatment. MedlinePlus notes that approaches aimed at helping people unlearn clenching behavior are more successful for daytime clenching. For some people, just relaxing and modifying daytime behavior is enough to also reduce nighttime bruxism. But methods that try to directly modify nighttime clenching — biofeedback devices, self-hypnosis and other alternative therapies — have not been well studied, according to MedlinePlus. That's a real gap, not a minor caveat: it means the version of bruxism you're least able to consciously manage is also the one science has the least direct guidance on.

Symptoms, including the ones that don't look dental

Grinding puts pressure on the muscles, tissues and other structures around the jaw, which is why MedlinePlus's symptom list reaches well past the teeth themselves: anxiety, stress and tension; depression; headache; muscle tenderness, especially in the morning; hot, cold or sweet sensitivity in the teeth; insomnia; and a sore or painful jaw.

Earache is on that list too, and MedlinePlus explains why in a way worth sitting with: partly because the structures of the temporomandibular joint (TMJ) sit very close to the ear canal, and partly because of referred pain, where you feel pain in a different location than its actual source. A man checking himself for an ear infection, finding nothing, and assuming it will pass is a plausible way this condition goes unrecognized for a while.

What it can lead to if left alone

MedlinePlus is reassuring on one point and blunt on another: bruxism is not a dangerous disorder, but it can cause permanent damage to the teeth and uncomfortable jaw pain, headaches or ear pain. The specific complications it lists include depression, eating disorders, insomnia, increased dental or TMJ problems, fractured teeth and receding gums — on top of the more immediate nuisance of grinding loud enough to wake a sleeping partner.

Self-care that actually helps

The goals of treatment, per MedlinePlus, are reducing pain, preventing permanent damage to the teeth, and reducing clenching as much as possible. Self-care steps it lists include applying ice or damp heat to sore jaw muscles, avoiding hard or dense foods like nuts, candy and steak, skipping gum, getting enough sleep, and learning physical therapy stretches for the muscles and joints on each side of the head. Reducing daily stress and learning relaxation techniques are named specifically as a way to help prevent bruxism in people prone to it.

Mouth guards, splints and Botox

To protect the teeth themselves, MedlinePlus points to mouth guards or splints as the standard approach — worn over the top or bottom teeth, sometimes designed to hold the jaw in a more relaxed position. A well-fitting splint should minimize the effects of grinding, though MedlinePlus notes some people find symptoms return once they stop using it, and that a splint may work less well over time; if one type doesn't help, another sometimes will. After splint therapy, adjusting the bite pattern may help some people. Separately, Botox injections into the jaw muscles have also shown some success in controlling clenching and grinding.

Where it overlaps with sleep apnea

Teeth grinding and sleep apnea aren't the same condition, but they show up together often enough to be worth knowing about if you have either. This site's article on under-recognized sleep apnea symptoms covers research finding sleep bruxism at markedly higher rates among sleep apnea patients than in the general population — one of several "non-classical" symptoms that paper argues get missed in people who don't fit the stereotype of an obviously sleepy, loud snorer.

None of that means every case of nighttime grinding points to undiagnosed apnea. But if grinding shows up alongside loud snoring, witnessed pauses in breathing, or daytime sleepiness, it's a reasonable prompt to read that article and consider whether a sleep study is worth raising with a doctor, rather than treating the jaw in isolation. NIDCR notes that polysomnography — an overnight sleep study, with sensors monitoring brain activity, heart rate and breathing, usually done in a sleep center — can be used to assess whether teeth grinding is actually occurring during sleep. It's worth knowing that this is the same kind of test used to diagnose sleep apnea, so a single overnight study can sometimes speak to both questions at once.