TORONTO -- Now that face masks have become a staple in our daily lives, some people have noticed an unfortunate side effect from wearing the protective coverings for long periods of time – bad breath.

The phenomenon, which has been dubbed “mask mouth,” is a real thing according to several Canadian dental associations that have offered tips on how to avoid it.

“Very simply put, mask mouth is the bad smelly breath underneath your mask,” Lesli Hapak, the president of the Ontario Dental Association (ODA) and a dentist based in Windsor, Ont., said during a telephone interview with on Friday.

Mask-wearing can result in bad breath for a number of reasons, according to Hapak, but the biggest culprit is poor oral hygiene.

“An increase in plaque and tartar, which is bacteria, can cause that bad smelly breath underneath the mask,” she said.

With people cooped up inside and not going out to see people as often, Hapak said that some people may be neglecting their regular oral hygiene habits.

What’s more, the COVID-19 pandemic forced dental offices across much of the country to close for approximately three months in the spring, which meant many Canadians missed their regular checkups and cleaning appointments.

Aaron Burry, the associate director of professional affairs for the Canadian Dental Association (CDA), said that extended mask usage can affect the balance of bacteria in the mouth. He said when people breathe while wearing a mask, there’s the risk it can increase the amount of bacteria in their mouth over time.

“You really want a nice neutral mouth,” he told during a telephone interview from Ottawa on Thursday.

“The saliva in your mouth is designed to do that, but at certain points, if the bacteria start to overwhelm it, then you can get a very acid mouth, you get bad breath.”

Hapak added that bad breath or mask mouth can also be caused by people eating strong-smelling food and the odour lingers underneath the mask for a long time. She also said a dry mouth, which can be the result of not drinking enough water while wearing a mask, can lead to bad breath too.

While bad breath may not sound like a serious problem, both Hapak and Burry said increased bacteria in the mouth and poor oral hygiene in general can have serious consequences.

Hapak, who specializes in periodontics, which is the diagnosis, prevention and treatment of gum disease, said ODA dentists have witnessed an increase in the number of cavities, decay, cracked teeth, and broken fillings during the pandemic.

As a periodontist, she said she has personally seen an increase in the severity of gum disease, which is like bone loss and bleeding gums, when people returned to the clinic after the lockdown period.

“Your dental health does influence your overall health,” Hapak said.

Burry said he’s heard anecdotally of increased dental problems during the pandemic, but he doesn’t have any statistics on it. However, he also stressed the importance of maintaining oral health.

“Oral health is a big part of overall health and well-being, it’s worth taking the time and effort to brush and floss every day, and enjoy healthy nutrition,” he said.

Although face masks can lead to bad breath and other oral health problems, Burry and Hapak said there are simple ways to prevent that from happening while still wearing a covering to stay safe during the pandemic.


  • Brush your teeth at least twice a day.
  • Floss between your teeth every day.
  • Don’t forget to brush your tongue too.
  • Swish your mouth with mouthwash before putting on a mask.
  • Drink lots of waters throughout the day. Stay hydrated.
  • Avoid alcohol, smoking, marijuana, and vaping because they can cause dry mouth, inflammation, enamel damage, teeth staining, and even oral cancer.
  • Avoid sugary foods and acidic drinks.
  • Chew sugar-free gum to increase saliva flow.
  • Regularly wash your reusable face mask or replace disposable masks.
  • Eat a balanced and nutritious diet.