Sleep Apnoea: CPAP or a Mouth Device? New Study Results
6 Oct 2026
In a small Brazilian crossover study published in October 2026, a digitally made mouth device that moves the jaw forward reduced night-time oxygen drops and snoring about as much as CPAP in 20 adults who had struggled to use CPAP [1]. The study is small and short, so it doesn't replace CPAP as the standard choice. It does suggest that a well-fitted device is worth discussing if you can't tolerate the mask.
Sleep Apnoea at a glance
- Study: 20 adults with obstructive sleep apnoea who were not using CPAP, tested at home under three conditions [1].
- Result: median oxygen desaturation index fell from 13.55 to 6.05 events an hour with the device and 5.30 with CPAP [1].
- Difference: CPAP gave slightly better blood oxygen levels; the gap was small [1].
- Limit: tiny sample, short follow-up, and the authors hold a patent on the device [1].
What is obstructive sleep apnoea, and why treat it?
Obstructive sleep apnoea (OSA) means the airway repeatedly narrows or closes during sleep, so breathing pauses and oxygen levels dip. People often notice loud snoring, unrefreshing sleep and daytime sleepiness. A partner usually spots the pauses first.
Treatment matters for how you feel in the day. In a 2025 meta-analysis of 17 randomised trials with 2,372 people, CPAP improved daytime sleepiness, processing speed and anxiety. Average use in those trials was about five hours a night [3].
What did the new study test?
Researchers in Brasília enrolled 20 adults whose OSA had been confirmed by an overnight sleep laboratory study. None of them were adhering to CPAP. Each person tried a mandibular advancement appliance, a custom-made mouthpiece that holds the lower jaw slightly forward. Then they did home sleep tests three times: with no treatment, with CPAP, and with the device [1].
Both treatments helped. Compared with no treatment, the median number of oxygen drops an hour fell from 13.55 to 6.05 with the device and to 5.30 with CPAP. The difference between the two was not statistically significant, and nor were differences in snoring, hypoxic burden or heart rate. Blood oxygen saturation was slightly better with CPAP [1].
Does that mean you can swap CPAP for a mouth device?
Not on this study alone. Everyone in it had fewer than 50 breathing events an hour, so people with the most severe OSA were left out, and 20 people is a very small group. The home tests were short, so we don't know whether the effect lasts or whether people keep wearing the device. The authors also disclosed that a patent application has been filed for the appliance they tested [1].
A separate meta-analysis of depressive symptoms is a reminder that the two treatments are not always equal. CPAP improved low mood in OSA (17 trials, 1,931 people), while mandibular devices showed no significant effect (6 trials, 315 people) [2]. Those results measure a different outcome, but they show why the choice should be individual.
| Question | CPAP | Mouth device |
|---|---|---|
| Oxygen drops an hour (median) | 5.30 | 6.05 |
| Blood oxygen saturation | Slightly better | Slightly lower |
| Depressive symptoms (meta-analysis) | Small improvement | No significant effect |
CPAP versus a mandibular advancement device, from the studies above [1,2].
What else helps alongside treatment?
A secondary analysis of a randomised trial in 25 adults with moderate to severe OSA tested eight weeks of resistance training three times a week. Sleep quality scores and quality of life improved compared with the control group, though daytime sleepiness did not change [4]. It is a small trial, so think of exercise as a support to treatment, not a substitute for it.
When should you get tested?
See a doctor if you snore loudly, wake choking, feel exhausted after a full night, or fall asleep at work or while driving. The right test is a sleep study, which shows how many breathing events you have and how severe they are. The right device or CPAP pressure can then be chosen from the results.
Getting help in Delhi
Brain Bridge Clinic in Safdarjung Enclave, New Delhi, offers overnight polysomnography with CPAP titration, which records your breathing, oxygen levels and sleep stages and, where CPAP is advised, finds the pressure that suits you. At an assessment we go through your sleep, snoring and daytime symptoms, and discuss whether testing is needed. If you've been told to use CPAP and can't tolerate it, bring that to your appointment and we can talk through options.
Related pages: Polysomnography CPAP Titration, Insomnia, Sleep Hygiene Program.
Frequently asked questions
Is a mouth device as good as CPAP for sleep apnoea?
In one small crossover study of 20 adults, the two reduced oxygen drops and snoring to a similar degree, though CPAP kept blood oxygen slightly higher. The study was too small to settle the question [1].
Who might consider a mandibular advancement device?
The study tested it in adults with OSA who weren't using CPAP, so it applies to people in that position. Whether it suits you depends on your sleep study and a dental assessment [1].
Does CPAP help with tiredness and mood?
A 2025 meta-analysis of 17 trials found CPAP improved daytime sleepiness, processing speed and anxiety [3]. An earlier meta-analysis found it improved depressive symptoms [2].
Can exercise help sleep apnoea?
In a small trial, eight weeks of resistance training improved sleep quality and quality of life in adults with moderate to severe OSA, though not daytime sleepiness [4].
How do I find out if I have sleep apnoea?
Through a sleep study ordered by a doctor. Loud snoring, witnessed breathing pauses and daytime sleepiness are reasons to ask for one.
References
- Morum T, Sampaio D, Hecksher JB, et al. Effectiveness of a fully digital mandibular advancement appliance compared with CPAP in the treatment of obstructive sleep apnea. Dental press journal of orthodontics. 2026;31(4):e262663. doi:10.1590/2177-6709.31.4.e262663.oar. PMID 42879578.
- Fu W, Li L, Zhang S, et al. Effects of CPAP and Mandibular Advancement Devices on depressive symptoms in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials. Sleep & breathing = Schlaf & Atmung. 2023;27(6):2123-2137. doi:10.1007/s11325-023-02829-w. PMID 37119355.
- Che L, Wang J, Wu R, et al. Effect of continuous positive airway pressure on cognitive impairment associated with obstructive sleep apnea: A systematic review and meta-analysis of randomized controlled trials. Cranio : the journal of craniomandibular practice. 2026;44(3):556-570. doi:10.1080/08869634.2025.2568806. PMID 41157896.
- de Almeida JRV, da Silva Ferreira DK, de Arantes Lima VD, et al. Effects of resistance training on subjective sleep quality, excessive daytime sleepiness, and quality of life in patients with obstructive sleep apnea: a secondary analysis from a randomized controlled trial. Sleep & breathing = Schlaf & Atmung. 2026;30(6). doi:10.1007/s11325-026-03842-5. PMID 42900248.