Obstructive sleep apnea (OSA) is a common disorder where breathing repeatedly stops and starts during sleep due to a blocked or narrowed upper airway. The standard treatment for moderate to severe cases is a Continuous Positive Airway Pressure (CPAP) machine, but many people struggle with its mask and forced air system. For those who cannot tolerate CPAP, oral appliances, often called mouthpieces, offer an alternative treatment method. These small, custom-fitted devices are designed to be worn at night to help keep the airway open.
The Mechanism of Oral Appliance Therapy
Oral appliance therapy works by physically altering the position of the structures in the mouth and throat to prevent the collapse of soft tissues during sleep. When a person with OSA falls asleep, the muscles surrounding the airway relax, which can allow the tongue and soft palate to fall back and block the flow of air. The mouthpiece counteracts this by providing mechanical support to the jaw and tongue.
The primary action of the most common devices is Mandibular Advancement, which involves holding the lower jaw slightly forward of its normal resting position. This forward movement pulls the tongue and soft tissues in the back of the throat along with it, effectively widening the space in the pharynx. By increasing the diameter of the upper airway, the mouthpiece reduces the likelihood of obstruction (apnea or hypopnea events). This repositioning keeps the airway patent, allowing for uninterrupted breathing and reducing the disruptive vibrations that cause snoring.
Types of Mouthpieces and the Custom Fitting Process
Oral appliances fall into two main categories based on their mechanism of action: Mandibular Advancement Devices (MADs) and Tongue Retaining Devices (TRDs). MADs are the most frequently prescribed type, resembling a custom-fitted athletic mouthguard that snaps over the upper and lower teeth. They use hinges or elastic straps to gently push the lower jaw forward and maintain that position throughout the night. Most clinically effective MADs are titratable, meaning a dentist can adjust the degree of forward movement in small increments to find the optimal setting for the patient’s comfort and effectiveness.
Tongue Retaining Devices (TRDs) work differently by focusing solely on the tongue rather than the jaw. A TRD is a device that uses a small bulb or suction mechanism to hold the tongue in a forward position, preventing it from collapsing backward into the throat. While less common than MADs, TRDs are sometimes recommended for patients who have few or no teeth, or those who experience jaw joint issues that prevent them from comfortably using a MAD.
The distinction between custom-fitted, prescription devices and over-the-counter (OTC) options is significant for safety and results. Custom-made appliances are fabricated from impressions of a patient’s mouth by a dentist specializing in sleep medicine. This professional process ensures a precise, comfortable fit and allows for necessary adjustments, which correlates with better patient compliance and treatment efficacy. OTC options, such as “boil-and-bite” guards, are a one-size-fits-all approach that lacks the clinical validation and adjustability of a prescription device.
Determining Candidacy and Effectiveness
Oral appliance therapy is recommended as a first-line treatment for patients with mild to moderate Obstructive Sleep Apnea. It is also a viable option for individuals with severe OSA who have failed to adhere to CPAP therapy (CPAP intolerance). Before treatment begins, a formal diagnosis of OSA, confirmed through a sleep study, is required to determine the condition’s severity.
While CPAP remains the gold standard for reducing apnea and hypopnea events, especially in severe cases, oral appliances often achieve comparable overall health outcomes. This is largely because patients show greater nightly adherence and long-term use with the smaller, more comfortable oral appliance than with a CPAP machine. About two-thirds of patients experience a significant reduction in the severity of their OSA with a custom MAD.
Common, usually temporary, side effects include jaw discomfort, teeth soreness, or excessive salivation upon waking. Long-term use can sometimes lead to minor, reversible changes in dental alignment or bite, making regular follow-up appointments with the prescribing dentist important. Patients with central sleep apnea or certain dental or jaw joint conditions are typically not considered good candidates for this treatment.