What we do with our teeth at night we couldn’t do during the day. Many of us know that we clench or grind our teeth at night or, we can even hear our partner doing it, but is it a sign of something bigger? What can it cause or be caused by?
The act of clenching our teeth when we’re sleeping, also called bruxism, is what’s called centrally mediated, meaning our brains do this automatically, much in the way we have restless leg syndrome. We have no control of initiating it and external factors rarely can stop it, like in the way iron supplements can stop restless leg syndrome. Because it’s centrally mediated, it’s extremely hard to see what is triggering it, but multiple studies in the last 15 years have brought to light a possible cause of at least 50% of the clenching events: how we breathe in our sleep. In overnight sleep studies, researchers have found that when we are sound asleep if our airflow decreases, even in the absence of any lack of oxygen, that we reflexively clench our teeth until the airways have restored their normal airflow, then we stop clenching. Naturally when we clench our teeth we are flexing and increasing the tone of our muscles of our upper airway including the tongue (this is why we get those indents on the sides of our tongues, from bracing it against our teeth) which is how we restore our breathing flow rate. This tightening (reducing the collapsibility of the upper airway muscles) is what helps to restore the airflow. We see this in real time when the flow has been restored and the clenching ends. This surprised many but it dovetails with other, much more numerous research showing that patients with sleep apnea are bruxing more than those that don’t and that sleeping on our backs, increases sleep apnea as well as increases bruxism.
So now we’re clenching, what other things can this lead to? Because clenching is so violent and so intense, and not only does it engage those upper airway muscles but also the neck and shoulder muscles, this can cause classic tension headaches as the greater occipital nerves get pinched between the second vertebrae and base of the skull. Many have observed that seeing a chiropractor for an adjustment immediately resolves this kind of headache, but generally returns because of the clenching.
This is how a sleep dentist, particularly one that understands how our jaws and TMJ function, can assist in reducing clenching and headaches. Unfortunately this knowledge isn’t common among medical professionals, including dentists, as there’s very little training on the subject in dental school. There’s zero training in medical school. But fortunately more and more dentists are learning this skill and are able to effect change in a very safe manner, which then makes sleeping with your jaw that much easier.
