Yes, it is!
And I can tell you as someone who wears one for most of the day due to the profession -being a dentist 🙂
If you are not good about brushing and flossing your teeth, you can smell your own breath. And most often, it is not the most soothing smell.
One of the biggest things that we have seen during the shut-downs is people loosing motivation to brush their teeth or floss (even have seen some who tell us that they have “washed their hair for us”!). But we got to remember that we need to upkeep our oral hygiene for us as our mouths are the entry point to our bodies. If we start there with a lot of bad bacteria and left over food, nothing good usually comes out at the end of the day.
Another issue is that a lot of us forget to drink water these days. Dry-mouth is another reason for bad mouth odor that one could smell under a mask.
So if no matter how much brushing or flossing is being done, or water being drank, yet the smell persists, you need to see a dentist rather quickly. And with most dental office staff fully vaccinated these days, don’t hesitate!