Do Sleep Apnea Mouthguards Move Your Teeth?
Clinically reviewed by Dr. Abinaash Kaur, DDS, RCDSO, on 2026-09-14. Dr. Kaur is a general dentist in Toronto (Bloor West Village) registered with the Royal College of Dental Surgeons of Ontario.
Yes, a sleep apnea mouthguard can keep working for years. People who started one more than ten years ago still report that it helps their sleep and their bed partner (Journal of the American Dental Association via PubMed).
Here's the other half. Years of nightly wear slowly shift your teeth, and the shift keeps going the longer you wear it (Journal of Evidence-Based Dental Practice via PubMed).
I've already written about what your dentist watches for with sleep apnea, including your two main options. That post answers "what can I do about it." This one answers "what does wearing the appliance for years do to my bite," so you can choose knowing both.
One thing to clear up first, because the word "mouthguard" does a lot of work in dentistry. A night guard for grinding is a different device with a different job. It cushions your teeth. It doesn't hold your jaw forward and it doesn't treat sleep apnea.
What does a sleep apnea mouthguard actually do?
It holds your lower jaw forward while you sleep. The clinical name is a mandibular advancement appliance, which is a mouthful, so I'll stick with mouthguard from here. Have no fear, it's less bulky than it sounds.
Moving the lower jaw forward pulls the tongue and soft tissue with it, and that keeps the airway open. Public Health Agency of Canada lists dental appliances that re-align the jaw among the treatment options, alongside weight loss and avoiding alcohol and sedatives before bed (Public Health Agency of Canada).
So is this the first thing you'd be offered? No. The same page calls CPAP, the mask that pushes pressurised air, the primary treatment (Public Health Agency of Canada).
Which one suits you isn't something a blog post can decide. Ask whoever diagnosed you, and ask whoever would make the appliance. Pretty much every useful answer here comes out of that conversation rather than an article.
Does it still work after ten years?
The people who stuck with it say so. A 2025 study in the Journal of the American Dental Association followed a group of 839 patients who started this treatment more than ten years earlier, and surveyed them about how they'd got on (JADA via PubMed).
A total of 121 people answered. They reported real improvement in their symptoms, less daytime sleepiness, and happier bed partners (JADA via PubMed).
I'll be straight about what that is and isn't. It's 121 people describing how they feel, a decade on, and the people who bother to answer a survey like that tend to be the ones still wearing the thing and happy with it. Those particular findings are self-reported, not measured overnight.
One detail from that survey stayed with me. The single most common reason people sought treatment in the first place was that their snoring was disturbing a bed partner, at 77.6% (JADA via PubMed). The people most likely to still be wearing it years later were the ones who'd had morning headaches before starting, who felt it improved their sleep, and whose partner was happy with it.
Sleep apnea is rarely a solo problem. Somebody else in the house usually noticed first. Was it your partner who sent you looking? It usually is.
What does nightly wear do to your bite?
It closes it, slowly and measurably. A 2024 systematic review and meta-analysis pooled 23 studies of people wearing these appliances for longer than a year (JEBDP via PubMed).
Your overjet is how far your top front teeth sit ahead of the bottom ones. On average it closed by about three quarters of a millimetre. Overbite, the vertical overlap, closed by about two thirds of one. The review found the change kept going the longer people wore the appliance (JEBDP via PubMed).
Under a millimetre sounds like nothing. Across years of nightly wear, it's the difference between a bite that meets where it used to and one that doesn't.
Why do the teeth move at all?
Because the appliance pushes on both jaws at once, in opposite directions, all night.
Here's the part most articles flatten into a single number, and flattening it loses the mechanism. The upper front teeth tip backward by an average of 2.10 degrees. The lower front teeth tip forward by an average of 1.78 degrees (JEBDP via PubMed).
Two opposite movements, closing the gap from both sides. That's why the overjet shrinks. The review also measured a small backward change in the position of the lower jaw itself, 0.33 degrees (JEBDP via PubMed).
An appliance that holds your jaw forward for eight hours a night is doing gentle orthodontics whether anyone intended it or not.
Is the evidence as solid on both halves?
Not quite, and it's worth knowing which half rests on what.
The tooth movement above was measured in millimetres and degrees, pooled across 23 studies. The "still helping after ten years" part comes from 121 people answering a questionnaire about how they feel.
That doesn't mean the appliance doesn't work. Oral appliances are a recognized treatment for sleep apnea (Public Health Agency of Canada), and the people who stay with one for a decade say it helps. It means the shift in your bite is the more precisely measured of the two, and it's the one nobody brings up.
The review itself stops short of calling the movement a problem. Its conclusion is that anyone wearing one needs monitoring over time (JEBDP via PubMed). Whether three quarters of a millimetre matters to you is a question for a chair, not a chart.
None of this is a fringe finding, either. The American Dental Association says plainly that these appliances have been linked to gradual dental changes over time, including a reducing overbite and overjet, alongside jaw joint aches and extra saliva (American Dental Association). It's expected, it's known, and it's the reason somebody should be watching your bite.
Should any of this stop you wearing one?
No, and please don't stop a treatment on your own because of something you read here.
Untreated sleep apnea is the more serious problem of the two. Keep wearing it if it was prescribed after a proper diagnosis. The sensible response to tooth movement isn't to abandon the appliance, it's to have someone watch your bite.
Whoever made your appliance should be checking your bite against where it started. Has anyone done that for you? If not, bring the appliance to your next dental visit and we can measure it. Changes caught early are easier to work with than changes discovered years later.
Say so out loud if your jaw aches in the morning or your bite feels different, rather than waiting to be asked. Our post on jaw clicking and TMJ covers what those symptoms can mean.
Who is this appliance actually for?
Mostly people with mild to moderate sleep apnea, after a diagnosis. There's an important second group, though, and it often gets left out.
The American Dental Association puts it this way: an appliance is commonly recommended for mild to moderate sleep apnea, and also for severe apnea in people who can't tolerate the mask (American Dental Association). So severe sleep apnea isn't automatically outside this conversation. If CPAP has been tried and genuinely can't be tolerated, an appliance is still on the table.
Severity isn't something anyone can eyeball from your teeth, which is the whole reason the order matters: diagnosis, then the conversation about what to use.
Get the diagnosis first, always. Canadian Thoracic Society guidelines recommend an overnight sleep study at a sleep laboratory, and Public Health Agency of Canada notes that 23% of Canadian adults told they had sleep apnea reported never being referred for that testing (Public Health Agency of Canada).
I've practised in Bloor West Village for about 25 years, and snoring comes up in the chair far more often than sleep apnea does. They aren't the same thing, and only a sleep study can sort one from the other. If tape or gadgets are what you've been trying, our post on mouth taping explains why a blocked nose is the reason not to.
Frequently Asked Questions
Q: Will a sleep apnea mouthguard move my teeth? Over years of nightly wear, a small amount, yes. A review pooling 23 studies of people wearing these for more than a year found the overjet closed by about three quarters of a millimetre and the overbite by about two thirds, and the change kept going with time (JEBDP via PubMed). The change is gradual and it's the reason your bite is worth checking periodically.
Q: Is a sleep apnea mouthguard the same as a night guard for grinding? No. A grinding night guard cushions your teeth against clenching forces. A sleep apnea appliance holds your lower jaw forward to keep the airway open, which is a different job and a different design. Our guides to night guards and how to stop grinding at night cover the grinding side.
Q: Should I use a mouthguard instead of CPAP? That's a decision for you and the clinician who diagnosed you, not something to settle from an article. Public Health Agency of Canada calls CPAP the primary treatment and lists dental appliances among the alternatives (Public Health Agency of Canada). Both have real roles, and which suits you depends on your severity and what you'll genuinely use.
Q: Do I need a sleep study first? Yes. Canadian Thoracic Society guidelines recommend overnight polysomnography at a sleep laboratory to diagnose sleep apnea, though portable home monitors are sometimes used (Public Health Agency of Canada). An appliance is something fitted after a diagnosis, never as a substitute for getting one.
Q: How long do these appliances keep working? Longer than many people expect. A 2025 study surveyed patients who had started this treatment more than a decade earlier, and the 121 who responded reported improvement in their symptoms, less daytime sleepiness and better partner satisfaction (JADA via PubMed). Bear in mind those are self-reported answers from the people who chose to reply.
Q: What should I ask at a dental visit if I wear one? Ask whether your overjet and overbite have changed since the appliance was made, and whether there's a record of where they started. A baseline is what makes later comparison possible. If no baseline exists, having one taken now is still worth doing.
Reviewed by Dr. Abinaash Kaur, B.Sc., DDS (University of Toronto Faculty of Dentistry), who has practised general and family dentistry in Bloor West Village for about 25 years. This article is general oral health information. It is not a diagnosis, not a substitute for an examination, and not advice about starting or stopping any prescribed treatment.
Wearing a sleep apnea appliance and wondering what it's done to your bite? Bring it with you and we'll have a proper look at how your teeth are meeting now. We're at 750 Annette Street in Bloor West Village, serving the Junction, High Park, and Baby Point. Book a visit with The Village Dentist and we'll take a look together.
