mandibular advancement device

A mandibular advancement device is a custom mouthguard worn at night that gently holds the lower jaw forward of its resting position. Because the tongue and the soft tissues of the throat are anchored to the jaw, pulling the jaw forward tows them forward too, enlarging the space behind the tongue and making the upper airway less likely to collapse during sleep.

Mechanically, the appliance fits over the upper and lower teeth and links them so the mandible — the lower jaw — sits a few millimeters anterior, often with the amount of advancement adjustable. This widens the airway behind the soft palate and tongue base and stiffens its walls, reducing both the vibration that causes snoring and the partial or complete collapse that causes hypopneas and apneas.

Oral appliances are an established treatment for snoring and for mild to moderate obstructive sleep apnea, and an important alternative for people with more severe disease who cannot tolerate CPAP. They are quiet, portable, need no electricity, and many patients find them easier to live with, which can translate into better real-world adherence than a mask.

Their limits are real. They are generally less effective than CPAP at fully abolishing severe apnea, and response varies between individuals, so follow-up testing is recommended to confirm benefit. Side effects include jaw and tooth discomfort, excess salivation or dry mouth, and, with long-term use, gradual shifts in tooth position or bite, so they are best fitted and monitored by a dentist experienced in sleep medicine.