A Custom Mouthguard Kept Pace With CPAP in Adults With Sleep Apnea and High Blood Pressure

CATEGORY: SLEEP & RECOVERY

A CPAP machine works only on the nights someone actually wears it, and plenty of people cannot live with the mask and the hose. A trial in Singapore put a custom mouthguard up against it. Over six months, adults with obstructive sleep apnea and high blood pressure who wore the jaw-advancing appliance at night saw their average around-the-clock blood pressure fall by 2.5 mm Hg. That met the trial’s preset bar for keeping pace with CPAP, the standard treatment, whose own group’s change was not statistically significant. The randomized trial, called CRESCENT, followed 220 patients and was published in the Journal of the American College of Cardiology.¹

Two Ways to Hold a Floppy Airway Open

Obstructive sleep apnea is a condition in which the throat repeatedly narrows or collapses during sleep, choking off airflow dozens of times an hour. Each episode jolts the nervous system, and over years that pushes blood pressure upward. The standard fix is CPAP, a bedside machine that blows gently pressurized air through a mask to splint the airway open. The challenger here was a mandibular advancement device, a dentist-fitted appliance that looks like a two-piece sports mouthguard. It works by nudging the lower jaw forward a few millimeters, much like propping a soft drinking straw so it cannot pinch shut.

Six Months, Measured Around the Clock

Three hospitals in Singapore enrolled 220 adults, most in their late fifties and early sixties, all of them carrying both high blood pressure and moderate-to-severe sleep apnea. Which device a patient received was settled by random allocation rather than by preference. The headline measurement was 24-hour blood pressure, taken by a wearable cuff that inflates at intervals through an entire day and night, once at the start and again six months later. The trial was built as a noninferiority comparison. The mouthguard would pass only if its blood-pressure result stayed within a preset margin of CPAP’s.

A Sensor Inside the Mouthguard Explains a Lot

The mouthguard passed. Its wearers’ 24-hour average fell 2.5 mm Hg from baseline while the CPAP group’s change was not statistically significant, and the between-group difference of 1.6 mm Hg in the mouthguard’s favor stayed well inside the preset margin. It also showed larger reductions on the secondary blood-pressure measures, especially overnight. Part of the explanation sat in a sensor embedded in each device: 56.5% of mouthguard users wore theirs six or more hours a night, against 23.2% of CPAP users. Daytime sleepiness improved similarly in both groups. All participants were Asian and most were men, in a single country, so the investigators caution that the result may travel imperfectly to other groups.¹

Fourteen Trials Point the Same Way

A 2026 pooled analysis of 14 randomized trials covering 1,141 patients, CRESCENT among them, reached the same bottom line. It found no meaningful difference between the two treatments in 24-hour or nighttime blood pressure, a small daytime edge for the mouthguard of about 2 mm Hg, and roughly 43 more minutes of nightly use.² The same analysis carries an important qualifier. CPAP remains clearly better at suppressing the breathing interruptions themselves, preventing about eight more per hour. The mouthguard’s blood-pressure showing reflects a weaker therapy worn long enough to do its work.

Key Takeaways

• Over six months, a custom jaw-advancing mouthguard lowered 24-hour blood pressure by 2.5 mm Hg in 220 adults with high blood pressure and moderate-to-severe sleep apnea, meeting the preset standard for keeping pace with CPAP.
• Mouthguard users wore their device far longer each night, with 56.5% managing six or more hours against 23.2% of CPAP users, which the researchers pointed to in explaining the result.
• CPAP is still the more powerful treatment for stopping apnea episodes themselves, preventing several more breathing interruptions per hour in a pooled analysis of 14 trials.
• The comparison ran mouthguard against CPAP rather than against no treatment, so it shows how the two measured up to each other and not whether either beats going untreated.

References

1. Ou YH, Colpani JT, Cheong CS, et al. Mandibular Advancement vs CPAP for Blood Pressure Reduction in Patients With Obstructive Sleep Apnea: The CRESCENT Trial. Journal of the American College of Cardiology. 2024;83(18):1760–1772. link
2. Cheng T, Wang Q, Wei W. Effects of mandibular advancement devices vs. CPAP on blood pressure in obstructive sleep apnea: a systematic review and meta-analysis of randomized controlled trials. Frontiers in Neurology. 2026;17:1846726. link