If you or your partner are known to snore overnight, we’ve got some unfortunate news: scientists have linked mouth breathing during sleep with increased levels of tooth decay. Why? Well, it has to do with saliva, acidity, and bacterial activation which are all impacted by breathing through the mouth (with or without snoring). The impetus of the study was a marked increase in dentists reporting patients complaining of dry mouth, especially during sleep or upon awakening. Oral dryness during sleep can be linked to sleep apnea and patients who rely on mouth breathing to make up for poor airway flow.
First, mouth breathing during sleep causes saliva to evaporate into the surrounding air. Think of how dry your mouth feels when you’ve got a cold and can’t breathe through your mouth due to congestion. This lack of moisture in the mouth isn’t just a problem with discomfort, however. Saliva is important both for moisture and for keeping the mouth’s acidity under control. Saliva contains base pH levels that protect tooth enamel and allow for a reduction in bacteria. Lack of saliva causes acidity levels to rise, creating an environment in the mouth where enamel is left unprotected.
A reduction in saliva can lead to increased acidity and result in tooth decay. Acidity in the mouth leads to loss of tooth enamel through erosion and tooth decay or caries cavities. When the mouth is acidic and there isn’t saliva to counterbalance the acidity, the enamel begins to slowly erode. Likewise, when bacteria in the mouth feast on food particles, they create acidity as a byproduct. That acidity causes tooth decay in the form of cavities.
Scientists measured mouth acidity during open- and closed- mouth breathing in a laboratory setting. They initiated the open-mouth breathing by placing a device over the nose that made nose breathing impossible. At different stages during the sleep study, acidity levels in the mouths of individuals who breathed through their mouths fell well below the threshold when tooth enamel begins to break down due to the presence of saliva in the closed mouth. The saliva reduces overall pH to that even below normal daytime breathing and thus has a protective effect on the teeth and gums by monitoring acidity. Mouth-breathing, however, has a detrimental effect by raising the pH levels in the mouth to those known for risk of tooth decay and damage. Sleeping with the mouth open has a negative effect on the mouth’s acidity and can cause tooth decay and cavities.
Mouth breathing is occasionally the result of a short-term effect like a cold and stuffy nose. Nasal decongestants and over the counter medications can help. In fact, taking these cold medicines may have a protective effect on your teeth by disallowing this pH imbalance during a cold or flu experience. While a stuffy nose for a few days isn’t necessarily enough to single-handedly cause tooth decay, we now know how a long term habit of mouth breathing can negatively impact oral health.
Other times, there may be a physiological reason for mouth breathing that could include an obstructed airway, narrow nose features, ongoing allergies or environmental hazards, a bedroom fan on too high, sleep apnea, or a host of other issues. If the mouth breathing is caused my a physiological factor, it may be worth it to alter the airway surgically or using a medical device like a mouth guard or CPAP or BiPAP machine.
In any case, the best protection for your teeth includes daily flossing, brushing in the morning and right before bed with a toothpaste containing fluoride, and biannual cleaning appointments with Dr. Shields. If you have questions about acidity, tooth decay, mouth breathing, or any other dental issue, contact Dr. Shields and the team at Smiles by Shields for an oral evaluation and cleaning.
Likewise, if you’re concerned about a child or partner’s mouth breathing and its effect on their oral health (and your sleep!), contact us for their appointment time today. An oral evaluation will include a look at physiological features that could impact wellness and oral health. With appropriate interventions, we can have your family’s teeth protected even during sleep!
Paddock, C. (2016, February 8). “Breathing through mouth during sleep may increase tooth decay risk.” Medical News Today. Retrieved from