The breath behind the bite.

I didn’t think much about airway in residency.

We were taught the orthodontic catechism — Class II malocclusion, arch coordination, bracket positioning, bond failures, the Andrews Six Keys. It was a beautiful, contained curriculum. Nobody was teaching us to listen for snoring in a parent’s voice when they described their kid. Nobody mentioned that the narrow palate I was about to expand might also be the reason a child slept with their mouth open every night.

The shift happened slowly, over a few years in private practice. I started noticing patterns I hadn’t been trained to name. The mouth-breathing seven-year-olds with gummy smiles and dark circles under their eyes. The teenage Class II patients whose mothers, in passing, would mention they snored “like a small chainsaw.” The forty-year-old with a constricted upper arch who came in to fix his crowded front teeth and, mid-consultation, mentioned his wife had taken to recording his snoring and emailing it to him at work.

Once I started seeing it, I couldn’t stop. The bite was the visible symptom. Often, the airway was the upstream cause.

This was the thing nobody had told me in school: how a face develops, how someone breathes at night, and how their bite functions are not three separate stories. They’re the same story, told three different ways. A child who breathes through their mouth from age four onward grows a face that accommodates that — long lower third, narrow upper jaw, posterior tongue posture, an open bite that wasn’t there at birth. By the time they get to me at twelve, I’m not just straightening teeth. I’m trying to undo eight years of compensation.

I should have been paying attention to my own face sooner.

About ten years ago, I sat in on an ENT talk at the hospital I was working in. I’d had chronic allergic rhinitis since I was a boy and I’d always known I didn’t breathe freely at night — I just thought that was the deal. The talk nudged me into doing a pulse oximetry test during sleep. Result: moderate obstructive sleep apnoea.

I was in denial about it for years. I rinsed my nose, used the spray, kept the airway open the lazy way. But the morning brain fog and the wake up on the wrong side of the bed feeling kept getting heavier. I eventually showed the result to another ENT, who recommended CPAP. I tried it. CPAP is the gold standard, and for many patients it’s life-changing — but I couldn’t get on with it. I felt like Darth Vader every night. After a few weeks, I quit.

What finally moved me wasn’t the symptoms. It was a sleep dentistry course, where I sat through case after case and properly understood how serious untreated OSA actually is — for the heart, for cognition, for how long you stay sharp. I went home, did a level-three home sleep study, and the result had moved from moderate to severe.

That’s when I made my first Mandibular Advancement Device — for myself.

A MAD is a custom dental appliance — a top tray and a bottom tray — that holds the lower jaw forward by five to eight millimetres during sleep. That bit of forward translation pulls the base of the tongue away from the back of the throat and opens the airway. It’s small, it’s quiet, and for the right patient it changes the night.

The first time I slept in mine, I didn’t sleep brilliantly — but I woke up clearer. Not fully rested, not transformed, just clearer. That was new. Within a couple of weeks the appliance had stopped being an object I noticed and become part of the bedtime routine. The brain fog lifted in a way I hadn’t realised was possible after years of treating it as a personality trait.

That experience changed how I describe MADs to patients. I don’t pitch them as a comfortable alternative to CPAP — they’re not always comfortable, especially at first. What I tell them is what I learned the hard way: untreated OSA gets worse, denial is part of the condition, and if the gold standard isn’t working for you, there are other tools that are better than nothing — often a lot better.

This is the part of orthodontics I think most about now. Straight teeth are nice. They’re a good outcome. But a treatment plan that ignores how someone breathes at night is, in my view, doing half the job. How a jaw develops, how someone breathes, how a bite actually works — same picture, all of it. Once you start looking at it that way, you can’t unsee it.