When Teeth Grinding Is Part of an Airway Problem

When you get right down to it, grinding your teeth while you sleep is kind of weird behavior. It doesn’t seem to serve any obvious purpose. Over time, it damages the hardest structures in the human body. Yet the body keeps on doing it. Night after night. Often for years.

You’ll often hear that this sleep bruxism — that’s the clinical name for it — is because of stress. Certainly, stress can play a role. But something else can play a much bigger role: the airway.

Researchers have found that sleep bruxism is particularly common in people with obstructive sleep apnea (OSA), a condition in which the airway is repeatedly blocked during sleep. Breathing stops or is restricted for 10 seconds or more, up to dozens of times every hour. The brain, sensing a drop in oxygen, spurs an arousal response — not enough to wake you but enough to get you breathing again.

Grinding may be part of that process. One leading theory is that the body recruits the jaw as part of its airway-rescue effort. Moving the lower jaw forward even slightly can get the tongue out of the way, open the pharynx, and restore airflow.

Recent research suggests that the relationship between bruxism and OSA could be even more layered.

Just this month, a study in Scientific Reports set out to ask a deceptively simple question: When oral appliance therapy improves OSA symptoms, does grinding ease up, too?

The study followed 23 adults who had been diagnosed with OSA through polysomnography. This standard in-lab sleep study simultaneously monitors brain waves, heart rhythm, airflow, oxygen saturation, body position, and limb movement while the subject sleeps. At the start of the study, participants averaged 17.4 breath stoppages — solidly in the mild to moderate range — and almost 13 bruxism episodes each hour.

Each participant was fitted with a custom mandibular advancement device (MAD), which helps with apnea by holding the lower jaw in a slightly more forward position. They wore their appliances nightly, then returned for another sleep study after at least six months. The average time between studies was about nine and a half months, which is long enough to reflect genuine adaptation rather than short-term adjustment.

So grinding could be monitored simultaneously in the sleep studies, each participant also wore an electromyography (EMG) device on the large chewing muscle known as the masseter, measuring electrical activity there as a reliable proxy for bruxing.

Analysis of the changes between the two sleep studies showed that oral appliance therapy significantly reduced the number of both apneic and bruxing events. But what was particularly interesting was that bruxism went down across the board, no matter how much — or how little — a participant’s OSA improved.

There was another interesting wrinkle in the data, as well. As the airway improved, a different arousal pattern emerged: Among those whose breathing improved most, there were fewer breathing-triggered arousals during REM sleep but more spontaneous micro-awakenings.

The appliance seemed to be acting on jaw muscle activity independently of the airway, stabilizing the jaw in a way that reduced grinding. The research team thus concluded that with oral appliance therapy, bruxism changes appeared to be driven by multiple factors at once: respiratory improvement, direct mechanical effects on the jaw, and possibly neurophysiological pathways we don’t totally understand yet.

Now, if the relationship between bruxism and sleep apnea were straightforward, treatment would be simple: Fix the airway, stop the grinding. Pick an appliance, advance the jaw, call it a day. What studies like this one tell us is that the relationship is complex and that each case should be taken on its own terms. No one intervention will resolve it in the same way twice.

Of course, patient-specific treatment plans have been part of Dr. T’s approach for years. Rather than default to a single device or protocol, she works with a wide range of appliances and therapies, choosing, combining, and adapting based on each patient’s specific anatomy, physiology, and needs. Function is the organizing principle. Restoring or supporting it requires understanding what’s actually driving the problem before reaching for a solution.

It’s also worth noting that the conversation about who qualifies for oral appliance therapy is shifting. Emerging evidence suggests that it may be effective even for severe OSA. For instance, a 2025 study in the Journal of Clinical Sleep Medicine measured oral appliance efficacy using sleep apnea-specific hypoxic burden instead of just counting breathing interruptions. It’s a metric tied directly to cardiovascular risk.

Before treatment, 94% of patients with severe OSA had hypoxic burden values above the high-risk threshold. After oral appliance therapy, that number dropped to 15%,

The picture emerging from this growing body of research is one where the mouth, jaw, and airway are deeply interconnected — and where thoughtful, individualized treatment has the potential to address more than one problem at a time.