Sleep Apnea & Oral Appliance Glossary

Understand the terms your doctor might use — and what they mean for your health.

Apnea

A temporary pause in breathing during sleep. These pauses can last from a few seconds to over a minute and may occur dozens of times per hour in people with sleep apnea.

AHI (Apnea-Hypopnea Index)

A number that measures how many times per hour you stop breathing (apnea) or breathe very shallowly (hypopnea) during sleep. An AHI above 5 may indicate sleep apnea.

CPAP (Continuous Positive Airway Pressure)

A machine that delivers air through a mask to keep your airway open while you sleep. It’s a common treatment for moderate to severe sleep apnea.

Dental Sleep Medicine

A field of dentistry focused on using oral appliances to treat obstructive sleep apnea and snoring — especially for patients who cannot tolerate CPAP.

Epworth Sleepiness Scale

A short questionnaire used to measure daytime sleepiness. It helps providers understand how much your sleep issues are affecting your daily life.

Home Sleep Test (HST)

A simple, at-home device used to test for sleep apnea. It measures breathing, oxygen levels, and heart rate while you sleep in your own bed.

Hypopnea

A partial blockage of the airway that causes shallow breathing during sleep. Like apnea, it lowers oxygen levels and disrupts restful sleep.

Mandibular Advancement Device (MAD)

A custom-fit oral appliance that gently moves your lower jaw forward to keep your airway open. It’s a popular alternative to CPAP.

NightLase®

A non-invasive laser treatment that tightens tissue in the throat to reduce snoring and improve airway flow. No surgery or appliances required.

Obstructive Sleep Apnea (OSA)

A sleep disorder where your airway collapses or becomes blocked during sleep, causing breathing pauses, poor sleep quality, and health risks.

Oral Appliance Therapy (OAT)

A CPAP alternative using a mouthguard-like device to treat snoring and sleep apnea. It’s comfortable, portable, and covered by most insurance plans.

Positional Sleep Apnea

A form of sleep apnea that worsens when you sleep on your back. Some patients benefit from positional therapy or oral appliances that allow better breathing in any position.

REM Sleep

A stage of deep sleep where dreaming occurs. Disruptions in REM sleep are common in people with untreated sleep apnea.

Sleep Study (Polysomnogram or HST)

A test that measures your sleep patterns, breathing, and oxygen levels. It can be done in a lab or at home, depending on your needs.