Do you grind your teeth at night?

Reviewed by Dr. Samar Fadavi, DDS

Short answer: Many adults grind or clench their teeth during sleep without knowing it. Common signs are a sore jaw or headache in the morning, flattened or chipped teeth, sensitivity and a partner who hears grinding at night. A dentist can check for wear and, if needed, make a custom night guard that protects the teeth while you sleep.

Why this guide

Night-time grinding, called sleep bruxism, is one of the most common things we spot during check-ups at our Danforth Avenue clinic. Patients are often surprised. They have no memory of grinding, yet their teeth show flat edges, tiny chips or cracks, and their jaw muscles feel tight when we check them. Stress, late shifts, long commutes, caffeine and poor sleep all play a part, and many of those are part of everyday life in Scarborough and across Toronto.

This guide explains how to tell if you grind, why it happens, what it does to teeth and jaws, and what you can do about it. It is general information, not a diagnosis. If you think you grind, a short exam will tell you much more. You can also read about how we make night guards on our night guards and TMJ page.

Grinding and clenching: what is the difference?

Grinding is when the lower teeth slide back and forth or side to side against the upper teeth under pressure. It often makes a sound that a partner or family member can hear.

Clenching is when the teeth press together hard without moving. It is silent, so it often goes unnoticed for years, yet it can put just as much strain on teeth, fillings and the jaw muscles.

Many people do both. Some do it mostly during sleep, others during the day while concentrating, driving or using a computer. Daytime clenching is often easier to catch once you know to look for it.

Signs you may be grinding at night

• Waking with a sore, tired or tight jaw
• Dull headaches at the temples, especially in the morning
• Teeth that look shorter, flatter or more even than before
• Small chips on the edges of the front teeth
• Teeth that feel sensitive to cold or to biting
• Cracked fillings, crowns or teeth
• A partner who hears grinding or tapping sounds at night
• Ridges or scalloped marks along the sides of the tongue
• A white line on the inside of the cheeks where the teeth meet
• Ear discomfort without an ear infection

One sign alone does not prove grinding. Several together, especially morning jaw soreness and visible wear, make it likely. Your dentist can compare your teeth with earlier x-rays and photos to see if wear is getting worse.

Why people grind their teeth

There is rarely one single cause. Grinding usually comes from a mix of factors that add up.

• Stress and anxiety: tension from work, school, money or family life often shows up in the jaw at night.
• Sleep quality: broken sleep, late shifts and frequent waking are linked with more grinding.
• Sleep breathing problems: grinding sometimes occurs alongside loud snoring or pauses in breathing. If you snore heavily or wake up gasping, speak with your doctor as well as your dentist.
• Caffeine, alcohol and smoking: these can make sleep lighter and grinding more frequent, especially later in the day.
• Some medications: certain medicines for mood and attention can increase clenching in some people. Never stop a medication on your own; ask your doctor if you notice a change.
• Bite and tooth position: a high filling or crown can trigger clenching, though bite alone is rarely the whole story.
• Habit: daytime clenching while focusing can become automatic.

Children grind too, often during growth and tooth changes. That is a different situation with its own guidance, covered in our guide on teeth grinding in children.

What grinding does to teeth and jaws

The forces involved in night grinding can be much higher than normal chewing, and they go on for long periods with no food in between to cushion them. Over months and years that adds up.

Wear and chipping

Enamel is the hardest substance in the body, but it does not grow back. Grinding slowly flattens the biting surfaces and edges of the teeth. Once the enamel wears through, the softer layer beneath wears faster and may become sensitive or yellow.

Cracks

Heavy clenching can cause fine cracks in teeth, especially molars with large fillings. A cracked tooth may hurt when you bite and release, or when you drink something cold. Our guide on cracked tooth symptoms and treatment explains these signs in detail.

Sensitivity

Wear and tiny flexing at the gum line can expose the inner layer of the tooth, which leads to sharp twinges with cold drinks or air. Our guide on sensitive teeth covers other causes and fixes.

Broken dental work

Fillings, crowns, veneers and implant crowns can chip or loosen under grinding forces. Protecting dental work is one of the main reasons dentists recommend a night guard.

Jaw muscles and joints

Clenching makes the jaw muscles work overtime. They can become tender, enlarged or tired. Some people develop clicking or pain in the jaw joint, known as the temporomandibular joint or TMJ. Our guide on TMJ jaw pain causes and relief explains that side of the picture.

How a dentist checks for grinding

At a visit, your dentist will usually:

1. Ask about morning symptoms, headaches, sleep, stress and medications.
2. Look for wear patterns, chips and cracks on the teeth.
3. Check fillings, crowns and other dental work for damage.
4. Feel the jaw muscles and joints while you open and close.
5. Look at the tongue and cheeks for pressure marks.
6. Compare with earlier photos or x-rays if you have them.

If grinding seems likely, the dentist will explain what they see and talk through your options. If a sleep breathing problem is suspected, they may suggest you see your family doctor for a sleep assessment.

Night guards: how they help

A night guard is a thin, smooth appliance that fits over the upper or lower teeth while you sleep. It does not stop the urge to grind, but it changes what happens when you do. Instead of tooth grinding against tooth, the teeth meet a durable plastic surface. That protects enamel and dental work and can ease strain on the jaw muscles for many people.

Custom guards versus store-bought guards

Pharmacy guards are made to fit many mouths. Some are soft and bulky, and some boil-and-bite types can change your bite if they fit unevenly. A custom guard is made from impressions or a digital scan of your teeth. It is thinner, fits closely, stays in place and is adjusted so your bite meets it evenly.

Soft guards can sometimes encourage chewing, while hard or dual-layer guards are often used for heavier grinders. Your dentist will suggest a material based on your wear, comfort and dental work.

Getting used to a guard

Most people need a few nights to adjust. You may notice extra saliva or a strange feeling at first. That usually settles within a week or two. If the guard feels tight, causes pain or changes how your teeth meet in the morning, bring it to the clinic for an adjustment.

Caring for a night guard

1. Brush and floss your teeth before putting the guard in.
2. Rinse the guard in cool water every morning.
3. Brush it gently with a soft brush and mild soap. Avoid toothpaste, which can scratch it.
4. Let it dry, then store it in a vented case away from heat and pets.
5. Never soak it in hot water or bleach.
6. Bring it to every check-up so your dentist can check fit and wear.

A guard with holes, cracks or a poor fit should be replaced, because it may no longer protect the teeth properly.

Habits that reduce grinding

A guard protects the teeth. These habits can lower how often and how hard you grind.

• Notice daytime clenching. Lips together, teeth apart, tongue resting on the roof of the mouth. Set a reminder on your phone to check a few times a day.
• Wind down before bed. A short routine of reading, stretching or slow breathing helps the body relax.
• Cut caffeine after midday. Coffee, tea, energy drinks and some soft drinks can keep the nervous system alert.
• Limit alcohol in the evening. It can make sleep lighter later in the night.
• Avoid chewing gum and pens. These train the jaw muscles to keep working.
• Warm compress. A warm cloth on the jaw muscles for ten minutes can ease morning tightness.
• Gentle jaw stretches. Your dentist can show you a few simple ones.
• Address stress. Exercise, time outdoors and talking to someone you trust all help. Ask your doctor about support if stress feels heavy.

When grinding has already caused damage

If teeth are already worn, chipped or cracked, your dentist will look at each one. Small chips may simply be smoothed. Larger areas of wear may be rebuilt with tooth-coloured filling material. A cracked tooth may need a crown to hold it together. In some cases the nerve becomes irritated and needs root canal treatment. Protecting the repaired teeth with a guard afterward helps the new work last.

Planning repairs and a guard together is important. If teeth are rebuilt but grinding continues unchecked, the new work faces the same forces as the old.

Steps to take if you think you grind

1. Ask your partner or family whether they hear grinding at night.
2. Notice morning jaw soreness, headaches or tooth sensitivity for a week or two.
3. Check yourself for daytime clenching while working or driving.
4. Book a dental exam and mention your symptoms.
5. If you snore loudly or wake tired, talk to your doctor too.
6. Follow the plan, which may include a custom night guard and habit changes.

What to avoid

• Ignoring a chipped or cracked tooth because it does not hurt yet.
• Using a sports mouthguard as a night guard. It is not designed for sleep or for grinding forces.
• Wearing a guard that no longer fits or has worn through.
• Filing or adjusting a guard yourself.
• Taking pain relievers every morning for jaw pain without seeing a dentist or doctor.

Daytime clenching at work and on the road

Not all clenching happens in bed. Many people press their teeth together while driving on the 401, answering emails, lifting at the gym or concentrating on a screen. Because it is silent, it is easy to miss. A simple check helps: several times a day, stop and notice where your teeth are. At rest, the lips should touch lightly, the teeth should be slightly apart and the tongue should rest on the roof of the mouth.

If you catch yourself clenching, let the jaw drop a little, breathe out slowly and relax the shoulders. Small sticky notes on a monitor or dashboard, or a phone reminder every hour, can build the habit. Over a few weeks, many people notice their jaw feels less tired by evening and their night grinding eases too. Daytime clenching is not usually treated with a guard, so awareness is the main tool.

When to see a dentist

Book a visit if you wake with jaw pain or headaches, notice chips or flat edges on your teeth, feel new sensitivity, or have been told you grind at night. See us sooner if a tooth hurts when you bite, a filling or crown breaks, or your jaw locks or clicks painfully. Learn more on our night guards and TMJ page.

Frequently asked questions

Can grinding go away on its own?

It can come and go with stress, sleep and life changes. Even if it eases, worn enamel does not grow back, so protecting the teeth during periods of grinding still matters.

Will a night guard stop me from grinding?

A guard protects the teeth and can ease muscle strain, but it does not switch off the habit itself. Habit changes and better sleep help reduce the grinding.

Should the guard go on the top or bottom teeth?

Either can work. Your dentist chooses based on your bite, dental work and comfort.

Can I wear my guard with clear aligners or a retainer?

Usually you wear one or the other at night. Some retainers can act as a light guard; ask your dentist what suits your situation.

Does insurance cover night guards?

Some workplace dental plans include them and some do not. We can help you check your plan and give you a written estimate first.

Is grinding linked to sleep apnea?

Grinding sometimes happens alongside sleep breathing problems. If you snore loudly, stop breathing during sleep or wake tired, speak with your doctor.