Breathing and orthodontics

Every time you draw a breath, you make a choice you are probably not aware of: nose or mouth. This page explains why that choice matters far beyond the nose itself — for sleep, for the way a child's face grows, for obstructive sleep apnea — and why I believe any orthodontic treatment should start with nose breathing.

Why any orthodontic treatment should start with nose breathing

I would argue that whoever made us humans — Mother Nature, God, Allah, Buddha or whoever you may think — had a plan. We have yet to identify body parts that are pointless, and the nose is no exception. Going through the literature on the subject, from George Catlin's "Shut Your Mouth and Save Your Life" (1875) to Sandra Kahn's "Jaws", I can't shake the feeling that we, in the orthodontic business, have to up our game in this regard.

What are the differences between nose breathing and mouth breathing?

Nose breathing	Mouth breathing
warmer, cleaner, moisturised air	cold, dry, unfiltered air
better sleep	snoring, sleep apnea, insomnia
18% more efficient gas exchange	reduced oxygen flow to the brain
6× nitric oxide (mood, immunity + more)	dehydration
proper orofacial development	improper orofacial development
promotes relaxation	chronic allergies, frequent colds

The video above shows how the tongue moves low and back in obstructive sleep apnea. In orthodontics we also treat this effect, when we treat patients whose lower jaw is positioned towards the back.

In orthodontics we have a myriad of clinical choices for correcting this facial imbalance, but very few of them actually consider breathing and the patient's apnea potential over a lifetime. Tooth extraction and distalisation are the two major choices with the highest chance of increasing that risk. Further down this page I go deeper into this connection — from airway geometry to the orthodontic decision.

"But I'm a mouth breather — there is no way for me to breathe through the nose…"

I would argue it is possible, because of a personal experience I will share with you here.

For over 20 years I breathed through my mouth at night, and every time I spoke with specialised doctors they said it was not bad enough to operate, and that I should try nose drops at night. Knowing that nothing is free and that medicating — especially long term — has side effects, I never actually pursued the treatment. I was at peace with my situation.

In the winter of 2020 I woke up one morning and realised my mouth was not dry — I had been breathing through my nose the whole night. I also realised this had been happening for a while, and it has stayed that way since, except when I had colds or allergic reactions. It made me very happy, but it also made me wonder: what had changed? How come, after 20 years of mouth breathing at night, I was now a nose breather? It took me a while, but in the summer of 2021 I finally understood what had happened: COVID-19 happened. No, not getting sick with it — going back to work after the lockdown, in May 2020.

I knew two things: saliva was the known transmission medium for the virus, and breathing through the mouth carried a higher chance of catching the disease than breathing through the nose. Did I want to reduce the chance of getting my loved ones sick? Then I needed to "shut my mouth to save their lives."

Behind an FFP3 mask, working with saliva, I instinctively kept my mouth shut for six hours every day. It was hard — sometimes I felt like I was drowning, other times like falling into an unnatural sleep — but fear is a powerful motivator.

How can I fix this?

If you think this could be important for you or for your child, you can try the hard way, like in my story — or a more manageable one, with a protocol I posted on X here. And if you would rather talk it through, breathing is part of how I read every patient at a first consultation.

OSA — obstructive sleep apnea

A forty-five-year-old patient arrives at the sleep clinic. He snores, he wakes up tired, his partner has heard him stop breathing. The polysomnography confirms obstructive sleep apnea. He is given a CPAP machine.

Nobody asks him what orthodontic treatment he had at thirteen.

And even if they asked, and learned that four premolars had been extracted, they still would not make the connection — because the sleep physician has no reason to, and the orthodontist who made the decision has long since disappeared from the patient's file.

This is the subject that concerns me most out of everything I do.

The geometry, in brief

The roof of the mouth is, at the same time, the floor of the nasal cavity. One wall, two chambers.

The shape of the upper arch decides the shape of the palatal vault. The palatal vault is the upper limit of the space the tongue lives in. And the tongue is the most voluminous structure in the airway.

When the upper arch is narrow, the vault is high and cramped, the tongue has less room to the sides — and its mass is pushed backwards, exactly into the region the column of air passes through.

When the arch is wider, the palate is lower and broader, the tongue has room at the sides, and the air has somewhere to pass.

At night, when muscle tone drops, the difference between the two situations becomes decisive.

What the studies show

This is not just geometric reasoning. The literature confirms the correlation, across populations and with different methods.

Studies published in recent years have shown that the posterior width of the maxilla correlates significantly with the total volume of the airway and with the minimum cross-sectional area, and inversely with the oxygen desaturation index in patients with severe apnea. Comparisons between apnea patients and control groups have found smaller intermolar distances in the apnea patients. An older study, published in the European Journal of Orthodontics, found posterior transverse discrepancies in half of the apnea group, compared with roughly one in twenty people in the control group.

The results converge. Wider, better-formed arches — better airway dimensions and less severe apnea. Narrow, high arches — the reverse.

The mechanism is not disputed. What has not been sufficiently integrated is the consequence for orthodontic treatment planning.

The orthodontic decision is a decision about breathing

The decisions that matter are the ones that affect the transverse dimension of the maxilla.

Extraction of four premolars with maximum retraction is the most consistent of them: it retracts the front teeth, narrows the arch, and reduces the transverse space available to the tongue. Distalisation without compensatory expansion produces a similar effect. And cases finished without correcting a transverse deficiency that was there from the start simply leave it in place — with the same implications.

The case finishes on time. The measurements at debonding fall within the accepted limits. The patient leaves satisfied, with straight teeth.

The cost is paid thirty years later.

I want to be fair: I am not saying that every orthodontic extraction produces sleep apnea. Apnoea has multiple causes — weight, muscle tone, ENT anatomy, genetic factors, age. Architecture is one of them, not the only one.

I am saying something else, narrower and, I believe, harder to contradict: that architecture is the only one of those causes the orthodontist influences directly — and that this influence is exercised at a moment when nobody is thinking about it.

The principle of deciding under uncertainty

The orthodontist treating a thirteen-year-old child has no way of knowing what polysomnography that person will have at forty-five.

The decision is made under uncertainty. And when the decision is irreversible, the principle I apply is simple: choose the option that preserves future flexibility.

Extraction is not reversible. The narrowed maxilla that results does not widen on its own once the bone has remodelled around the new positions. The patient who arrives at forty-five with apnea cannot have the maxilla they had at thirteen given back to them.

What can still be done

For patients already in this situation, I work with a few instruments.

• Mandibular advancement devices. They hold the lower jaw slightly forward during sleep, which pulls the tongue out of the airway. They work well in mild and moderate forms and are, for many patients, easier to tolerate than CPAP.
• Muscular re-education. Tongue tone and the nocturnal breathing pattern can be trained. On their own they do not resolve a severe obstruction, but they contribute — and they have no adverse effects.
• The reopening and implant protocol. For the patient treated with extractions years ago, who returns with apnea and with the dental signature of the original case: I reopen the extraction spaces orthodontically, bringing the dentition back towards its former dimensions, as far as the bone allows; implants are placed in the extraction sites, in collaboration with the restorative dentist; and then the patient works on tongue posture, because the reopened space has to be occupied.

About the last one, it must be said openly what it is: a recovery protocol for a problem that should never have been created. It takes two to three years, it costs a great deal, and it involves implant surgery and sustained work on the patient's part.

Patients often ask me whether it is worth it, compared with a CPAP. The honest answer is that it depends on the person. CPAP works when it is tolerated — and many patients do not tolerate it. The reopening protocol restores the anatomical condition instead of managing the symptom. For someone who does not tolerate CPAP and has the necessary resources, it is the right answer. For someone who tolerates it well, CPAP is the right answer.

The point is not that the protocol is universally correct. The point is that the initial treatment should never have produced the situation.

The signs worth checking

• constant snoring, with or without pauses observed by a partner;
• unrefreshing sleep, waking up tired, a dry mouth in the morning;
• daytime sleepiness, falling asleep at the wheel or at the desk;
• morning headaches;
• repeated awakenings during the night, sometimes with a feeling of choking;
• blood pressure that is difficult to control.

The diagnosis of apnea is made by polysomnography, not in the orthodontic practice. What I can do is see whether there is an architectural component — and, if there is, what can still be changed.