Teeth grinding, known medically as bruxism, is a repetitive clenching, grinding, or bracing of the jaw that can happen while you’re awake, asleep, or both. About one in five people worldwide experience it. For some, it’s a harmless habit that comes and goes. For others, it signals an underlying issue like stress, a sleep-breathing problem, or a medication side effect, and it can cause real damage to teeth and jaw muscles over time.
Two Distinct Types of Grinding
Daytime and nighttime grinding are considered separate conditions with different triggers. Awake bruxism involves clenching your teeth together or bracing your jaw during the day, often without realizing it. It tends to show up during periods of concentration, frustration, or anxiety. You might notice it while working at a computer, driving, or scrolling your phone.
Sleep bruxism is a rhythmic or sustained grinding that happens during sleep. Because it occurs unconsciously, many people only discover it when a partner hears the sound or a dentist spots the damage. Sleep bruxism is closely linked to brief arousals during the night, moments when your brain partially wakes up and your jaw muscles activate involuntarily. The latest sleep disorder classification system, updated in 2023, now distinguishes between grinding that’s simply a motor behavior and grinding that qualifies as a clinical disorder based on whether it causes pain, injury, or other problems.
What Causes It
There’s no single cause. Bruxism sits at the intersection of stress, brain chemistry, airway issues, and sometimes medication.
At the neurological level, the brain’s stress-processing regions have extensive connections to the nerve system that controls your jaw muscles. When you’re under chronic stress or anxiety, those pathways can become overactive. Disruptions in serotonin and dopamine, two chemical messengers involved in mood and movement, are also implicated. This helps explain why grinding often worsens during emotionally demanding periods of life.
Sleep apnea is another common trigger. When your airway narrows or collapses during sleep, your jaw muscles may clench in an effort to reopen the passage or lubricate throat tissue that dries out from labored breathing. If you grind at night and also snore, wake up with a dry mouth, or feel unrested in the morning, an airway problem could be driving the grinding.
Certain antidepressants are well-documented triggers. SSRIs and SNRIs can cause bruxism by flooding nerve connections with serotonin, which suppresses dopamine and leads to involuntary jaw movement. A 2018 systematic review found that paroxetine carried the highest risk, roughly 3.6 times more likely to cause sleep bruxism than not taking the medication. Venlafaxine and duloxetine also showed significantly elevated risk. If your grinding started or worsened after beginning an antidepressant, the medication is a likely contributor.
Who Gets It
Global prevalence data shows that about 22% of people grind their teeth, with sleep bruxism affecting roughly 21% and daytime clenching around 23%. Women are more affected than men across both types. About 15% of adult women experience sleep bruxism compared to 8% of adult men. For daytime clenching, 18% of adult women report it versus 9% of adult men. Children grind too, with rates around 9 to 11% in both boys and girls, though many outgrow it.
Signs You Might Be Grinding
Because sleep bruxism happens unconsciously and daytime clenching is often automatic, you might grind for years before connecting the dots. The signs tend to accumulate gradually.
Inside your mouth, a dentist may notice flat, worn-down tooth surfaces, tiny chips along the edges of front teeth, or cracks in molars. Your tongue can develop a scalloped, ripple-edged appearance from being pressed repeatedly against your teeth. The inner lining of your cheeks may show a white ridge from chronic pressure.
Outside your mouth, the clues are often muscular. Soreness in the jaw muscles when you wake up, tension headaches that start at the temples, and a tight or fatigued feeling when chewing are all common. Some people experience earaches or a clicking jaw joint without any ear or joint disease. If you wake up with a sore jaw more than a couple of times a week, grinding during sleep is a likely explanation.
When Grinding Becomes a Problem
Not all grinding requires treatment. Experts increasingly recognize that some bruxism is a normal motor behavior, not a disorder. Occasional clenching during a stressful week or mild grinding during sleep that causes no symptoms may not need any intervention at all.
It crosses into problem territory when it causes tooth fractures, persistent jaw pain, headaches, disrupted sleep, or damage to dental work like crowns and fillings. Severe grinders can wear through enamel entirely, exposing the softer layer beneath and creating sensitivity to hot and cold. Long-term heavy grinding can also enlarge the jaw muscles, changing the shape of your face.
How It’s Managed
Management depends on the cause and severity. For most people, the first step is a custom-fitted night guard, a hard or soft plastic tray worn over the teeth during sleep. It doesn’t stop the grinding itself, but it protects tooth surfaces from further damage and can reduce morning jaw soreness.
If stress is the primary driver, addressing it directly often helps. Cognitive behavioral therapy, relaxation techniques, and simply building awareness of daytime clenching (catching yourself and consciously relaxing your jaw) can reduce the habit significantly. Some people benefit from physical therapy focused on the jaw muscles and stretching exercises for the joint.
When a medication is triggering the grinding, switching to a different drug or adjusting the dose often resolves it. This is a conversation to have with your prescriber, not a change to make on your own.
For sleep apnea-related grinding, treating the breathing problem typically reduces or eliminates the bruxism. A continuous positive airway pressure device or an oral appliance that holds the jaw forward can address both conditions simultaneously.
Botulinum toxin injections into the jaw muscles have gained popularity as a treatment option. A randomized controlled trial found that injections significantly reduced grinding activity at four weeks, but the effect wasn’t sustained at twelve weeks. The strongest results came from injecting multiple muscle groups rather than the jaw muscles alone. This approach can be useful for people with severe symptoms who haven’t responded to other treatments, but it requires repeat sessions and isn’t a permanent fix.
What Grinding Means for Your Teeth Long Term
Left unmanaged over years, chronic grinding can shorten and flatten teeth noticeably, crack molars to the point of needing crowns or extraction, and contribute to temporomandibular joint problems that make it painful to open your mouth fully. The financial cost of repairing grinding damage adds up quickly, which is one reason dentists flag even mild signs early.
The good news is that most grinding responds well to straightforward interventions. A night guard, stress management, or treating an underlying sleep disorder resolves the issue for the majority of people before serious damage occurs. If your dentist has mentioned signs of wear or you’ve noticed jaw tension that wasn’t there before, identifying the trigger early gives you the most options.