Teeth Grinding and Clenching Guide: Managing Grinding During Sleep and Clenching During the Day

Teeth grinding (bruxism) is mainly grinding or clamping the upper and lower teeth during sleep, while clenching is the habit of biting down hard when tense or concentrating while awake. Materials from the Korea Disease Control and Prevention Agency (KDCA, 질병관리청) and the National Health Insurance Service (NHIS, 국민건강보험공단) list the two habits as typical behavioral contributors to temporomandibular disorders (TMJ disorders), and explain that abnormal tooth wear and enlarged chewing muscles can appear with them. Management centers on combining an occlusal splint that protects the teeth with behavior therapy that helps you notice and reduce the habit.

Published 2026-11-08 · Updated 2026-11-08 · DentalStatics editorial team

Key facts

Link to TMJ disorders	Teeth grinding and clenching when tense are behavioral contributors (source: Korea Disease Control and Prevention Agency (KDCA) and Ministry of Health and Welfare)
Findings that may appear together	Abnormal tooth wear, painless enlargement of the chewing muscles (source: Korea Disease Control and Prevention Agency (KDCA))
Role of an occlusal splint	Reduces grinding and abnormal function, prevents tooth wear and loosening (source: Korea Disease Control and Prevention Agency (KDCA))
Time the appliance is worn	Mostly worn during sleep (source: National Health Insurance Service (NHIS))
Content of behavior therapy	Correcting bad oral habits, awareness of jaw and tongue posture, recognizing and easing stress (source: Korea Disease Control and Prevention Agency (KDCA))

How do teeth grinding and clenching differ?

Teeth grinding is grinding the upper and lower teeth sideways or biting hard during sleep, sometimes with noise. Many people do not know they do it, and a family member sleeping nearby often hears the noise and notices first.

Clenching is the silent habit of holding the teeth tightly together while awake, and it shows up especially while driving, concentrating on computer work, or under stress. In Ministry of Health and Welfare material, a dental professor at the National Health Insurance Service Ilsan Hospital named the habit of clenching the teeth when tense as one that affects the jaw joint.

What signs show grinding or clenching?

It is a habit that is hard to notice yourself, so it is often guessed from marks left on the body. If several of the signs below overlap, have a dentist check the condition of your teeth and muscles.

Jaw or temples feel stiff and tired in the morning
Front-tooth edges or the chewing surfaces of molars are worn flat
Tooth marks remain on the inner cheek lining or the edge of the tongue
The chewing muscles on both sides of the face look hard and enlarged
A family member says they heard teeth grinding during sleep

How do they affect the jaw joint and teeth?

Grinding or clamping can repeat during sleep or while concentrating, building up strain on the chewing muscles and the jaw joint. The KDCA explains that oral habits like grinding can accompany TMJ disorders, and that painless enlargement of the chewing muscles and abnormal tooth wear can appear together.

When teeth wear down, sensitivity can develop, and filling materials and prostheses can break. People with implants or crowns should tell the dentist about the habit, because the force of grinding passes straight to the prosthesis.

If the edges of the front teeth wear evenly flat or the contours of the chewing surfaces of molars disappear, the dentist will ask about grinding. Worn enamel does not grow back, so the goal of grinding management is to protect the teeth so that wear does not progress further.

How are grinding and clenching managed?

Grinding during sleep is hard to stop by will, so the main method is an occlusal splint that covers the teeth to spread the force and protect them. The NHIS notes that splints are often worn at night, and making and adjusting a splint is a non-covered item in Korea.

Daytime clenching is reduced with behavior therapy. While resting, learn a posture with the lips closed, the upper and lower teeth slightly apart, and the tip of the tongue resting lightly on the palate behind the upper front teeth, and check yourself several times a day on whether you are clenching right now. Practice recognizing and reducing stress as well.

When is other medical care needed?

If you snore heavily or are told that your breathing seems to stop during sleep, you need to check for a breathing problem during sleep along with the grinding. For grinding with snoring, it is safer to get sleep-related medical care in addition to dental care.

If clenching newly appeared after a change in the medicine you take, discuss it with the prescribing doctor. If anxiety or depression is severe and it is hard to control the clenching habit, getting psychological counseling alongside is also an option.

Common myths and facts

Myth: Grinding only counts if it makes noise.

Silently clenching the teeth is a habit in the same category and also strains the muscles and joint. Daytime clenching makes almost no sound.

Myth: Wearing a splint makes the grinding habit disappear.

A splint mainly spreads the grinding force and protects the teeth. To reduce the habit itself, behavior therapy and stress management are also needed.

Frequently asked questions

Why does teeth grinding happen?

The cause of grinding is not summed up as a single one. The starting point of management is to reduce factors that raise muscle tension, such as stress, and to check sleep habits and the medicines you take.

Is a grinding splint covered by National Health Insurance?

The NHIS non-covered information portal lists making and adjusting occlusal splints, including the occlusal stabilization splint, as non-covered items. Costs differ by clinic, so also check the type of splint and whether adjustment costs are included.

My child grinds teeth too. Is that okay?

Children sometimes grind their teeth during sleep too. If the teeth wear down noticeably or the child complains of jaw pain, have it checked at a dental clinic, and also mention whether snoring or mouth-open sleeping goes with it.

Is there a simple way to fix clenching?

One way is to use phone alerts or sticky notes to check several times a day whether you are clenching now. Slightly separating the teeth and relaxing the shoulders each time you check helps you notice the habit.

Does enlarged chewing muscle need treatment too?

Even without pain, it can be a sign that the clenching habit is continuing. Rather than starting treatment for muscle enlargement alone, begin with habit management and discuss any needed treatment at a dental clinic.

References

Korean version →