Betty,
I see you've already gotten some advice from folks who know better than I about nose breathing. Thank you for starting this thread, though, because I will be trying some of these techniques in the coming months, as hay fever season approaches.
As a life-long mouth breather, I made sure to get a full-face mask from the start. Mom (known to all here as Catnapper) is after me to use a nasal mask, telling me my leak rate will go down and all that airflow through my nasal passages will dry out that area and keep it clear, and that I'll become a nose-breather instead of having my jaw hang to the ground all the time like a caveman's (Of course, being as she's my mother, she usually puts it in nicer terms than those).
Keep at it! The best is yet to come! You WILL start feeling better!
Learning to stop mouth breathing
Nose breathing
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