Two main types of oral appliances treat obstructive sleep apnea: mandibular advancement devices, which push the lower jaw forward, and tongue-retaining devices, which hold the tongue in place using suction. Mandibular advancement devices are far more common and make up the vast majority of prescriptions. Both work by keeping the airway open during sleep so soft tissue doesn’t collapse and block breathing.
Mandibular Advancement Devices
A mandibular advancement device (MAD) is essentially a pair of custom-fitted trays, one for each dental arch, connected by a mechanism that holds the lower jaw in a forward position. By pushing the jaw forward, the device pulls the base of the tongue away from the back of the throat and stretches the soft tissue connections between the tongue, soft palate, and the walls of the airway. The most significant effect is widening the airway from side to side, which helps prevent the collapse that causes apnea events.
These devices are adjustable. A dentist trained in sleep medicine sets the initial jaw position at roughly 70% of the maximum distance you can push your lower jaw forward. From there, the device is gradually advanced over weeks or months in a process called titration. Each adjustment is small, often just 0.1 mm per turn of a built-in key, with 1 mm of total advancement at a time. Adjustments are typically spaced two to three weeks apart to let your jaw muscles and joint adapt. The goal is to find the position where your symptoms resolve or further advancement becomes uncomfortable.
Tongue-Retaining Devices
A tongue-retaining device (TRD) takes a different approach. Instead of repositioning the jaw, it uses a soft bulb that fits over the tongue tip and holds it forward with gentle suction. This pulls the tongue nearly twice as far forward as a mandibular advancement device (about 6.8 mm compared to 3.5 mm in imaging studies), which also opens the airway behind the soft palate.
TRDs are less commonly prescribed but can be useful for people who don’t have enough teeth to anchor a jaw-advancing device, or who have jaw joint problems that make mandibular advancement painful. Because they don’t attach to the teeth, they sidestep many of the dental side effects associated with long-term MAD use. The tradeoff is that many people find the suction on the tongue uncomfortable, and compliance can be lower.
How Well Oral Appliances Work
Oral appliances reduce the number of breathing interruptions per hour in about 86% of patients. The average reduction is around 10 events per hour, with about a third of patients achieving at least a 50% drop. However, only about 12% of patients see their breathing events fall below 10 per hour, which is the common threshold for effective treatment. These numbers are modest compared to CPAP, which remains the most effective treatment overall.
Where oral appliances consistently outperform CPAP is in patient satisfaction and nightly use. One comparison found satisfaction rates of 76% for oral appliances versus 43% for CPAP among people using their device more than four hours per night. A device that gets worn every night at a moderate level of effectiveness can sometimes deliver better real-world results than a more effective device that stays in the nightstand drawer.
Current clinical guidelines recommend oral appliances for adults with obstructive sleep apnea who can’t tolerate CPAP or prefer an alternative. For severe sleep apnea, CPAP remains the first-line treatment, and oral appliances are reserved for patients who don’t benefit from or can’t use CPAP.
Custom-Made vs. Over-the-Counter Devices
Custom-fabricated devices are made from impressions or digital scans of your teeth, then built on a positive model of your dental arches. This process ensures a precise fit and allows for the fine adjustments needed during titration. Over-the-counter “boil and bite” devices exist, and at least one short-term study found similar efficacy over a 12-week period. But researchers have cautioned that long-term data on side effects and compliance with non-custom devices is lacking, and current guidance suggests that if a non-custom device is used at all, it should serve as a temporary trial before transitioning to a custom appliance.
Newer manufacturing methods using 3D printing and digital design are making custom devices faster to produce and potentially more comfortable. In early pilot testing, patients rated comfort levels of 9 out of 10 for gum comfort and nearly 10 out of 10 for jaw joint comfort. These digital workflows also allow dentists to make adjustments to the design before the device is ever printed, reducing the back-and-forth of traditional fabrication.
Side Effects of Long-Term Use
In the first few weeks, common side effects include tooth soreness, jaw pain, dry mouth, excessive salivation, and gum irritation. These are generally mild and fade as you adjust to wearing the device nightly.
Long-term use is a different story. Over two or more years, mandibular advancement devices cause small but measurable changes to the bite. Studies comparing oral appliance users to CPAP users found that the vertical overlap of the front teeth decreased by about 1.2 mm and the horizontal gap between upper and lower front teeth decreased by about 1.5 mm. Roughly 20% to 28% of patients experienced shifts in how their back teeth align. There’s also a tendency toward developing crossbites in the back teeth over time. These changes are driven by the sustained forward pressure on the lower jaw, and the greater the nightly advancement, the more the bite tends to shift.
These dental changes are the main reason ongoing monitoring by a dentist trained in sleep medicine matters. Regular checks of your bite, tooth alignment, and jaw joint function allow early detection of shifts before they become significant enough to affect chewing or comfort.
Who Can and Can’t Use Oral Appliances
You need enough healthy teeth to anchor the device. Active periodontal (gum) disease, significant tooth loss, or teeth that are too loose to support the trays are all potential barriers. Jaw joint disorders can also be a problem, since the device places sustained forward pressure on the joint for hours each night. Limited jaw mobility, meaning you can’t push your lower jaw forward very far, reduces both the range of titration and the likely effectiveness.
If you’re currently wearing braces or a retainer, an oral appliance isn’t an option until your orthodontic work is complete. People with severe oxygen drops during sleep, particularly when blood oxygen falls below 70%, may not get enough improvement from an oral appliance alone to protect against the cardiovascular consequences of untreated apnea. And practically speaking, you need enough hand dexterity to place and remove the device yourself each night.
What Getting One Involves
The process starts with a sleep study confirming obstructive sleep apnea. For Medicare coverage, you’ll need documentation of your symptoms, a focused physical exam of your upper airway and heart and lungs, and a validated sleepiness questionnaire like the Epworth Sleepiness Scale. A face-to-face encounter with a prescribing physician and a written order are required before the device is delivered.
From there, a dentist qualified in dental sleep medicine takes impressions or digital scans of your teeth and records your bite position. The device is fabricated, fitted, and then begins the titration process, which unfolds over several visits across weeks to months. Medicare covers custom-fabricated oral appliances under the durable medical equipment benefit, but the device must meet specific design criteria. It must be individually made from a full-arch impression, and the mechanism for adjusting jaw position must use a specific type of hardware. Devices that rely on elastic bands, hook-and-loop attachments, or monoblock construction don’t qualify for Medicare reimbursement.
The initial 90-day period after delivery covers fitting and adjustments. Devices that need ongoing modifications beyond that window to maintain fit or effectiveness are classified as dental therapies rather than durable medical equipment, which changes the coverage picture entirely. If you have private insurance, coverage varies widely, but most plans that cover oral appliances follow similar documentation requirements.