You’ve just imagined bruxism, more commonly known as grinding of the teeth.

This clash of teeth against teeth was called “brukhé,” or gnashing, by the ancient Greeks. Nowadays, experts tend to agree that bruxism is more nuanced and varied than that: Characterized by some as a “behavior” and by others as a “disorder” in otherwise healthy individuals, bruxism is repetitive jaw muscle activity that involves grinding, clenching, bracing, or thrusting.

Wakeful clenching, known as daytime or awake bruxism, and sleep grinding, known as sleep or nighttime bruxism, are related but distinct conditions with both unique and shared treatment protocols. Some people engage in a combination of the two.

“Grinding of the teeth is officially bruxism, while clenching, which is related, is a different parafunctional jaw habit,” says James M. Uyanik, DDS, a clinical assistant professor at New York University College of Dentistry in New York City and the director of the NYU Orofacial and Head Pain Clinic.

Almost half of all children go through a period of nighttime grinding, while up to one-third of the general U.S. population experiences bruxism at some point in their lives, according to the Academy of General Dentistry, a professional organization of general dentists from the United States and Canada.

If Google searches are any indication, research shows bruxism has risen since the COVID-19 pandemic began — not surprising, given bruxism’s link to stress. Still, oral health professionals such as Anne Clemons, DMD, a general dentist with the Cleveland Clinic in Ohio, say bruxism is dramatically underreported — “especially these days.”

That may be in part because many grinders and gnashers have no idea that they’re bruxing.

Who’s at Risk for Teeth Grinding?

According to a study published in 2019 by the Journal of Research in Medical Sciencesout of Isfahan University, many youngsters who grind outgrow the problem before adulthood. Those who continue into maturity and those who acquire the habit later in life range from occasional bruxers to powerful gnashers who can shatter dental work. “Anyone can be a bruxer,” says Dr. Uyanik. But some people are more at risk than others.

The stressed “Someone undergoing major changes or facing stressful events, such as moving to a new location, starting a new job, dealing with a birth, a marriage, a death, or a divorce in the family, is at particular risk,” Uyanik says.

A study published in the September 2019 issue of the International Journal of Environmental Research and Public Health found a strong positive correlation between perceived stress levels and the amount of grinding. This relationship was dramatically, albeit anecdotally, illustrated in an ABC News story from July 2021, about U.S. dentists reports of cracked teeth and broken dental work — casualties of intense grinding — soaring during the pandemic.

“Even when people are oblivious to their own grinding,” Dr. Rao says, “stressful background conditions can increase it, and this pandemic has been a major one.”

Problem sleepers With the majority of bruxers overworking their jaw muscles overnight, Dr. Clemons begins the diagnostic journey with queries about sleep. “I’ll ask whether it’s good and restful, or if there’s some other disorder involved,” she says.

For example, a misaligned bite (when the bottom and top teeth don’t properly meet) and breathing problems during sleep, such as nocturnal asthma and sleep apnea, can occasionally contribute to nighttime bruxism. Indeed, nighttime bruxism is often considered a sleep disorder that calls for people to have their overnight behavior monitored and analyzed.

“It could be critical in identifying possible additional sleep and breathing concerns that may contribute to or be related to bruxism events while sleeping, so they don’t go unaddressed,” Clemons says.

Caffeine or alcohol users and abusers Excessive consumption of coffee or alcohol can increase the tendency to grind, possibly by altering sleep patterns through overstimulation and dehydration, respectively. Tobacco and recreational drugs may also be bruxism risk factors.

Genetically predisposed An article in the Spring 2020 Journal of Craniomaxillofacial Research described a genetic predisposition to grind, and one study, reported online in the January 2018 Biomedical Reports, suggested that bruxers tend to share traits such as anxiety. Occasionally, an inherited dental misalignment will lead to bruxism. “For these people, the grinding will decrease after we improve the problem with their bite,” says Clemons.

Antidepressant users Bruxism is among the rare but possible side effects of some selective serotonin reuptake inhibitor (SSRI) antidepressants, which rank among the most-prescribed drugs in the United States.

Diagnosed with Parkinson’s disease or other conditions People with Parkinson’s disease, dementia, gastroesophageal reflux disorder (GERD), epilepsy, night terrors, or attention deficit hyperactivity disorder (ADHD) are more likely than the general population to develop a bruxing habit, according to the Mayo Clinic. So, too, are people who face some ongoing mental illnesses.