Dr Seb Lomas: Could Your Mouth Be Affecting Your Sleep?

You probably think of snoring as a noise problem. But what if it’s actually a breathing issue?

Persistent snoring may be a sign your airway isn’t staying as open as it should - and your mouth plays a bigger role in breathing than you might think.

The position of your tongue, how you breathe through your nose and how your jaw responds during sleep can all influence your airway.

We spoke to biological dentist and BON CHARGE Scientific Advisory Board member Dr Seb Lomas to explore the connection between the tongue, airway and sleep.

What happens when you snore?

Research suggests snoring happens when airflow through the upper airway is partly restricted during sleep, causing relaxed soft tissues in the throat to vibrate.¹

“The tongue should be up here,” Dr Seb demonstrates, lifting the tip of his tongue to the roof of his mouth, behind the teeth.

“So when you're lying down at night, the air can go through the nose, behind the tongue, behind the soft palate, which is almost acting like a hammock.”

If the tongue sits further back or lower during sleep, it can narrow the airway, making it harder for air to pass through smoothly and contributing to the vibrations that cause snoring.

Mouth breathing vs nasal breathing

When you breathe through your nose, air passes through the nasal passages before reaching the lungs. When you breathe through your mouth, you bypass this route entirely.

(Photo by iStock of a man mouth breathing whilst sleeping) 

“We're designed to nasal breathe,” Dr Seb says.

Nasal breathing is generally considered the body's preferred route for breathing at rest. The nose filters, warms and humidifies incoming air, while the nasal passages also produce nitric oxide, which is carried into the lungs during nasal breathing and may help support blood flow and respiratory function.³

Mouth breathing isn't inherently harmful - there are times when breathing through the mouth is necessary, such as during intense exercise or when the nose is blocked. But habitual mouth breathing, particularly during sleep, can change the position of the tongue and jaw and may affect the stability of the upper airway.

“Some people nasal breathe during the day, but the tongue's in the wrong place. So then when they sleep at night time, they mouth breathe,” Dr Seb explains.

This is where the connection to snoring becomes important. If the mouth falls open during sleep, the tongue may sit lower or further back, potentially reducing the space available for airflow. As air moves through a narrower airway, the surrounding soft tissues can vibrate, producing the sound we recognise as snoring.

Nasal breathing and a tongue resting against the roof of the mouth work together to support a more stable, controlled airway.

“So, tongue position biomechanically optimizes nasal breathing,” Dr Seb says.

Healthy breathing depends on how the nose, tongue, jaw and upper airway work together to keep airflow moving smoothly.

It’s important to know that switching from mouth to nasal breathing isn't something to force overnight.

“If someone’s used to mouth breathing, it’s going to feel very, very strange,” says Dr Seb. “It’s about just gently training it over months.”

Read More: How Red Light In Your Toothbrush Can Transform Your Smile

Why does tongue posture matter?

If the tongue is involved in keeping the airway open, its position matters beyond the hours spent sleeping.

(Photo by iStock of a woman sleeping in bed) 

Dr Seb says the tongue should naturally rest against the roof of the mouth, helping to support nasal breathing and maintain space in the upper airway.

The muscles of the tongue and surrounding structures can be trained, which Dr Seb works on through myofunctional therapy and airway-focused exercises.

“We call it airway diversity for adults or myofunctional therapy for kids,” Dr Seb explains. “Essentially, you’re toning and training the eight different internal and external muscles of the tongue to raise the soft palate and create more space to breathe.”

A systematic review and meta-analysis found myofunctional therapy may improve measures of obstructive sleep apnoea, snoring and daytime sleepiness, although it is usually considered a supportive therapy rather than a standalone fix.²

“There’s a really good analogy called the six foot tiger in the three foot cage,” he explains.

“The tiger is the tongue and the cage is the teeth.”

In some modern populations, dental arches appear to be smaller than in historic samples.⁴ This may mean less available space for the teeth - and potentially for the tongue - although arch development is shaped by a mix of genetic and environmental factors.⁴˒⁵˒⁶

The takeaway is simple: the tongue needs enough space to rest comfortably. When the structures around it don't provide enough room, its resting position and relationship with the upper airway may change.

The focus, then, is on where the tongue rests and how it functions. And according to Dr Seb, this is something that can still be trained in adulthood: “You can still do it as an adult, you can still train [your tongue to fit inside your teeth].”

For Dr Seb, the combination of nasal breathing and good tongue posture can help the airway remain more stable during sleep.

“If that tongue is living in the roof of the mouth more, it’s not going to block the airway as much,” he says. “It’s not going to automatically activate [the fight or flight response] when it should be in rest and digest.”

Could teeth grinding be a sign of an airway issue?

Snoring isn't the only nighttime behaviour that may offer clues about how you're breathing.

Dr Seb also sees a potential connection between airway restriction and teeth clenching or grinding.

Dr Seb describes sleep-related breathing problems as existing on a spectrum, with sleep apnoea at the more severe end and less obvious forms of sleep-disordered breathing sitting somewhere in between.

“At one end of the scale, you have sleep apnea,” he explains, “and there's this gray area in the middle, which is sleep disordered breathing.”

When the airway becomes narrower during sleep, the body can respond by activating muscles around the jaw and airway.

“When you’re in deep sleep, the body is still monitoring your airway,” explains Dr Seb. “If your airway collapses, the sympathetic nervous system kicks in, causing you to clench your teeth to help open the airway.”

That doesn't mean every case of teeth grinding is caused by a breathing problem. But persistent clenching or grinding, particularly alongside snoring or other signs of disrupted sleep, could be a reason to investigate how well your airway is functioning overnight.

What are the signs you might be mouth breathing at night?

You might not know how you breathe while you sleep, but your mouth can sometimes offer clues.

(Photo by iStock of a man getting a dental examination) 

• Clenching teeth or jaw
• Grinding teeth
• Snoring
• No energy, tired
• Worn or broken teeth
• Gum problems
• Dry or coated tongue
• Stained teeth
• Acid wear on teeth

“Clenching, grinding, snoring, no energy,” are all things he says can prompt him to investigate the airway, alongside dental changes such as worn or broken teeth and gum problems.

Other signs he looks for include a dry or coated tongue and stained teeth. “Those things can mean the tongue is not self-cleaning at night time from the roof of the mouth,” says Dr Seb, potentially indicating that it isn't maintaining its usual resting position.

“Trouble staying awake during the day, needing naps throughout the day, concentrating, focusing, and just generally not having enough vitality for life and energy” can be signs that sleep may not be as restorative as it should be.

And there is one connection Dr Seb says is particularly easy to miss: acid wear on the teeth.

“One telltale sign that someone may have sleep-disordered breathing is erosion on the inside surfaces of the teeth,” says Dr Seb. He links this to what can happen when the airway repeatedly collapses during sleep, potentially contributing to episodes of silent reflux.

What can you actually do about snoring?

There’s no single fix for snoring because the underlying cause can vary. But if you’re looking to support healthier breathing at night, Dr Seb suggests starting with the basics.

1. Open up your nose

Nasal dilators can help physically widen the nasal passages, making it easier to breathe through your nose while you sleep. Dr Seb recommends trying these before considering mouth taping.

2. Be cautious with mouth taping

If you can comfortably breathe through your nose, a small piece of mouth tape may help encourage nasal breathing and discourage mouth breathing. But Dr Seb is clear that it shouldn’t completely seal the mouth.

“Don’t seal the whole mouth,” he says. “Just do a little. So you can still at least mouth breathe if you need to.”

If your nose is blocked, you struggle to breathe through it, or you suspect you may have sleep apnoea, mouth taping isn't something to experiment with on your own.

3. Consider your sleeping position

Dr Seb says elevating the upper body can help reduce the effect of gravity on the airway. If you want to try this, a gentle incline is preferable to simply stacking pillows, which can bend the neck forward. Side sleeping may also help keep the airway more open.

4. When to investigate

And perhaps most importantly, don't simply accept persistent snoring as something you have to live with.

“I do think clenching, grinding, snoring and low energy are signs that something needs investigating,” says Dr Seb. “For me, it’s a reason to investigate the airway.”

Snoring is common, but Dr Seb believes that shouldn’t mean we simply accept it: “Just because it’s common is not normal.”

If you regularly snore, wake up gasping or choking, experience pauses in breathing during sleep, or feel excessively tired despite getting enough time in bed, speak to your GP or a qualified sleep professional.

Sign up to get early access to exclusive discounts and wellness tips. 

References

1. De Meyer, M. M. D., Jacquet, W., Vanderveken, O. M. & Marks, L. A. M. Systematic review of the different aspects of primary snoring. Sleep Med. Rev. 45, 88–94 (2019).

2. Camacho, M. et al. Myofunctional therapy to treat obstructive sleep apnea: a systematic review and meta-analysis. Sleep 38, 669–675 (2015).

3. Lundberg, J. O. Nitric oxide and the paranasal sinuses. Anat. Rec. 291, 1479–1484 (2008).

4. Warren, J. J., Bishara, S. E., Yonezu, T. & Saunders, K. L. Comparison of dental arch measurements in the primary dentition between contemporary and historic samples. Am. J. Orthod. Dentofacial Orthop. 119, 211–215 (2001).

5. von Cramon-Taubadel, N. Global human mandibular variation reflects differences in agricultural and hunter-gatherer subsistence strategies. Proc. Natl Acad. Sci. USA 108, 19546–19551 (2011).

6. Corruccini, R. S. An epidemiologic transition in dental occlusion in world populations. Am. J. Orthod. 86, 419–426 (1984).