Sometimes when we discover we might have a sleep breathing disorder like obstructive sleep apnea (OSA), it doesn’t happen during a checkup with the family doctor, but with the family dentist.
This is a fancy name for clenching the jaw or grinding the teeth. While it can happen at any time of day, it can frequently occur at night. Called sleep bruxism, it can cause people to awaken feeling unrefreshed, sometimes with morning headaches or neck and jaw pain.
Doctors don’t often address the issue of sleep bruxism unless a patient brings it up. This usually happens because a bed partner complains about the unbearable noise it can make.
However, dentists are poised to identify underlying problems with bruxism, even in those who aren’t aware they clench or grind. Sometimes bruxism results from a misalignment of the teeth or jaw, for instance.
A dentist may discover evidence of bruxism during one of your cleaning appointments. This can present as eroded tooth surfaces, unexplained loose teeth, or cracked or chipped, even broken, teeth that are not the result of trauma to the face or jaw.
Sleep bruxism is an oral health problem, to be sure. But it is also considered a sleep related movement disorder characterized by uncontrolled, involuntary physical movement during sleep (in this case, movement of the jaws).
If your dentist observes problems with your teeth that suggest bruxism, they may ask about tooth sensitivity or muscular pain in the head, face, jaw or neck, as well as rawness or dryness of the lips, gums, or throat.
Why? People with undiagnosed obstructive sleep apnea (OSA) experience many of these same warning signs… and are also known to clench their jaws or grind their teeth at night. According to the National Sleep Foundation, about a quarter of all people with obstructive sleep apnea experience sleep bruxism.
It’s unclear why the two are linked, but researchers believe that arousals caused by upper airway resistance lead to a stress response felt throughout the body. Once awoken from an apnea, your heart and respiratory rates increase while stress hormones flood the bloodstream. Increased muscle activity in the jaw inspired by this stress response may be a cause for clenching or grinding.
Another theory is that, during an apnea, an episode of snoring, or even a partial obstruction (called a hypopnea), the tissues along the upper airway collapse. This creates airway instability which may provoke the brain to signal to the jaw to tighten its muscles in order to stiffen the softer sides of the throat. By doing so, this can help avoid or attenuate this collapse of airway tissues so you can receive adequate air flow without interruption as you sleep.
Finally, bruxism may be the body’s response to another sleep-related malady: gastroesophageal reflux disease (GERD). GERD also has an unsettling relationship with sleep apnea and may be another concern raised chairside by your dentist.
Also known as acid reflux or heartburn, GERD occurs when the contents of the stomach breach the valve at the lower esophagus and spill upward into the throat. The high-acid contents can burn the tissues of the upper airway. They can also be (dangerously) inhaled (or aspirated) into the lungs while one sleeps. The brain may also signal the jaw muscles to tense up to create a barrier against this.
If, after visiting your dentist, you discover a problem with bruxism, your dentist may refer you back to your primary care physician to look into the possibility that you have sleep apnea.
In that case, you may be asked to perform a take-home overnight test (called a Home Sleep Apnea Test, or HSAT) or—depending upon your doctor’s protocols and your qualifications—you may be asked to attend an overnight sleep study (polysomnogram) in an actual sleep lab. Either test will verify or rule out the possibility that you have OSA.
Dr. Mark Burhenne at the Ask the Dentist blog suggests these are the new “At-Risk Groups for Sleep Apnea” when a case of bruxism is also identified:
Of course, the standard risk factors also apply. If you’re overweight, if you snore frequently and loudly, if you have hard-to-control blood pressure by an unknown cause, or if you suffer from extreme daytime fatigue, these are all indicators you should consider getting a sleep consult.
The good news: If you have sleep apnea, you’ll treat it with the gold standard therapy, positive airway pressure (PAP). Usually this means continuous PAP (CPAP). Alternately, you may be prescribed an oral appliance, which your dentist will custom build for you.
(In the event your bruxism is unrelated to OSA, you may be fitted with a mouthguard to prevent further damage.)
Studies show that patients with both bruxism and sleep apnea can dramatically improve both sleep health and oral health with either therapeutic application.
It’s also recommended that you use this opportunity to be proactive about your overall health and sleep habits and take care of some lifestyle protocols. This can include weight loss, nasal allergy treatment, GERD prevention, and smoking cessation. By doing so, you’ll breathe better as you sleep, which will return alertness and energy to your days.