Why is Mouth Breathing Bad? A Clinical Condition, Not Just A Bad Habit

[Dr. Gopi Shah]
When you say functional nasal breathing, can you define it? Is that just not mouth breathing?

[Dr. Colleen Plein]
Essentially, yes. It's unobstructed nasal breathing with your mouth closed. The way we are meant to breathe is with our mouth closed, with our tongue sitting fully on the roof of our mouth and unobstructed airflow through the nose. Doing that has a variety of benefits that we'll talk about. That's the goal is mouth closed, breathing through your nose.

[Dr. Gopi Shah]
Mouth breathing, and this probably sounds so ignorant, especially, but it's never just habit.

[Dr. Colleen Plein]
It can become habit. It starts out, and most of the problems often start in childhood, as I'm sure you have seen in your practice, that there's some obstruction in the nose. We start out as obligate nasal breathers, everybody knows that. Our larynx is high up in the pharynx, but it descends as we get older. That's an ontogeny recapitulates phylogeny sort of thing. If you look at the animal kingdom, in animals that don't have speech, their larynx is much higher, and their tongue sits much further forward. You don't see animals with obstructive sleep apnea.

There's actually this anthropologic theory called the Great Leap Forward, which is basically how humans develop speech. What happens is the larynx descended, and the tongue came further back. We basically prioritize the pharynx over the larynx to allow us resonant speech and all the speech sounds. In doing that, the tongue came further back. Now when we lay down, we have this big muscle sitting in our mouth and our throat that can now obstruct our airway. We have the benefits of speech, but there are evolutionary downsides to that.

[Dr. Gopi Shah]
Can we, just to set the stage, talk about the importance of nasal breathing and downsides of mouth breathing? I think at a very basic level, I tend to think that breathing is breathing. You breathe through either-- maybe you have a tracheostomy, you're breathing through a hole in your neck, you're breathing through your nose, you're breathing through your mouth. If you're moving air, you're breathing. Why does it matter?

[Dr. Colleen Plein]
That's what we're taught. Oxygen is oxygen. That may be true in terms of sustaining life, but it's not necessarily true in terms of optimal function. The nose does a bunch of different things. We know that it warms and humidifies air. We know when someone has a tracheostomy, if someone has a laryngectomy, what's their biggest problem? Humidification. They don't have humidification. It filters the air that we breathe. That's very important for our immune system. The turbinates grab particulate matter. Nasal breathing is important for ciliary function inside the nose.

Part of the reason, one of the theories goes that, why do we see enlarged tonsils in kids? If they're breathing through their mouth, the tonsils, which are lymphoid organs, are getting exposed to all this air and all these particles that they shouldn't be. Now you have tonsillar hypertrophy as a secondary problem. It's not the primary problem causing the sleep apnea or those issues. It's secondary from not breathing through their nose. Our sinuses also make nitric oxide, which is produced in the mucosal lining of our sinuses. It's then put out into the nasal airway.

Nitric oxide is a vasodilator. It helps with our blood pressure. It decreases stress. It also increases the efficiency of oxygen transfer to the tissues. There's actually been studies done on elite athletes that when you change them from being nasal breathers to mouth breathers in an exercise test, their exercise capacity reduces significantly. We also know that people who breathe through their mouth actually breathe at a faster rate than people who breathe through their nose.

That actually ends up in, instead of actually having our carbon dioxide levels in our blood be slightly too low, and very subtle shifts in pH in our blood have effects on our body. There's more. I could go on, but those are, I'd say, some of the major things. The thing about it is if you look in the population, about 75% of people have some sort of issue like this. It's a problem of humanity.

[Dr. Gopi Shah]
Yes, absolutely.

[Dr. Gopi Shah]
I apologize if this is jumping ahead, but for the child then who comes in from the age of two to six, you take out the tonsils and adenoids, or let's say it's just an adenoid problem, but they still are mouth breathing because, like you said, there might be mid-face hypoplasia. There may be retrognathia. There may be the high-arched palate. We're not always jumping to turbinates at that age. What do you do? What else should we be addressing? Because I'm like, "Oh, you're not snoring. You're not pausing. That's great. A little mouth breathing, that might just be habit." Do you grow out of that? I don't know.

[Dr. Colleen Plein]
What's so fascinating about that is I know that as a pediatric ENT, you know when you look at the studies, "Well, why do the studies show that there's a big benefit for removing the tonsils and adenoids in the short term, but in the long term, these kids still have problems?" What you're talking about is exactly the issue. We're addressing essentially the symptom, but not the problem. There's a few different things. Number one, early orthodontic intervention, super important. There are people, Kevin Boyd in Chicago and others, who really advocate for early maxillary expansion, because when you're a kid, those sutures haven't fused yet. You have a lot more wiggle room. Yes, expansion for these kids.

[Dr. Gopi Shah]
How early are we talking?

[Dr. Colleen Plein]
Basically, they'll tell you as early as they can tolerate. They really say four or five is the first time they should be having at least an evaluation if you're concerned about them having these problems because you can make such a big difference. That's number one. Usually, these people will work with people who are called myofunctional therapists. Myofunctional therapy is about promoting these behaviors of keeping the tongue on the roof of your mouth, keeping your lips sealed, strengthening the tongue, changing the diet. There are these therapists who are really trained to help in these problems.

Unfortunately, there's not a ton of them, and finding a good one is difficult, but they are out there and these interventions can make a humongous difference because we can impact the facial growth when they're younger, but the older they get, it's harder and harder to do. Once a kid is at 11 or 12, you're already behind the eight ball. The biggest thing that I advocate is actually you just got to look for these things. If you look for them, you will see them everywhere. My practice isn't-- I don't do pediatrics, but I see this in my own kids, and being able to do that is going to save so much pain and heartache and intervention later on, not to mention their quality of life overall.

[Dr. Gopi Shah]
Changing the diet in kids, does that-- basically having them chew more and eat less soft stuff?

[Dr. Colleen Plein]
Yes, within reason. At ENT, I'm still an airway doctor. I know people are super into baby-led weaning and those sorts of things. No, I don't want your child to choke on food, but age-appropriate, keeping things in their least processed form. It's difficult because the question is, you have to balance safety with functionality, but also again, minimizing processed food, which we know is good dietary advice overall.

[Dr. Gopi Shah]
Just regardless. Yes, for sure.

[Dr. Colleen Plein]
Exactly.

[Dr. Gopi Shah]
In terms of orthodontics and myofunctional therapy, we said the younger, the better, but of course, in terms of access and insurance and knowledge. It's not like this is part of our normal repertoire of workup and treatment options. My question though is, is there an age at which these things don't help, or is this something that you do for any-- whether the patient is 20, 40, 60 years old, who comes in that you say, "Okay, we're going to try myofunctional therapy." Is there a certain ages or things like that?

[Dr. Colleen Plein]
No, they work with all ages, and they have age-appropriate things. There are even age-appropriate-- just this morning I was giving my daughter this little thing. It's cool. It's called a myomunchie. Basically, it looks like a tiny little-- almost like a football mouth guard, but it's got little prongs inside of it and little things for them to do with their tongue. Basically, it's something to give them in their mouth that they're like, "Oh, I can chew on this. Oh, I can play with my tongue with this." It basically stimulates their using those muscles.

No, there's no age in which it doesn't help, but of course, and this comes back to what we were originally talking about, none of this will help you if you can't breathe through your nose. Learning to close your mouth and do all those things, well, if your nose is obstructed, you're going to naturally do that because you need to breathe. You have to look at this stuff in conjunction with getting the kids to breathe through their nose.

That's where I go back to what you were talking about about turbinates. With those kids and the sleep-distorted breathing and those sorts of things, I do start to pay attention to the nose a little bit earlier because my threshold-- and again, I don't do a ton of this, but I will get patients sent to me. I work with a dentist who does a lot of this stuff on kids and they'll say, "We've been doing everything and everything, this kid still can't breathe through their nose." I'm like, "Okay, well, we can do a turbinate reduction on them." Is it super common? No. Is there any real super downside to doing it? Not really.