Obstructive sleep apnea is generally caused by two factors working together: anatomy and physiology.

Anatomy refers to the development of the bones and soft tissues of the face and throat. Some people with sleep apnea have bones that are too small or excess soft tissue, which can restrict the airway.

Physiology refers to muscle tone in the throat during sleep. Reductions in muscle tone can cause the throat to collapse during sleep, resulting in airway blockage.

Understanding both anatomy and physiology helps identify the causes of sleep apnea and guide treatment recommendations.

Several tests may be used to help determine the causes of sleep apnea and identify where airway collapse occurs during sleep.

These tests often include:

• A sleep study, which provides information about breathing patterns during sleep

• A CT scan, which evaluates the structure of the jaws, throat tissues, and airway

• Drug-Induced Sleep Endoscopy (DISE), which allows direct examination of the throat during a sleep-like state

Together, these tests provide information about both the anatomy and physiology contributing to sleep apnea.

A sleep study is an overnight test that measures airflow and oxygen levels throughout the night.

The results help determine the severity of sleep apnea and provide additional details about breathing patterns during sleep. For example, a sleep study may show whether sleep apnea is worse when sleeping on the back compared to the side.

In some cases, an existing sleep study may need to be updated before treatment.

A CT scan is a three-dimensional imaging study that provides high-resolution images of the jaws, throat tissues, and airway.

These images allow measurements to be be taken to evaluate the anatomy of the airway and help determine which sleep apnea procedure(s) may be appropriate.

Drug-Induced Sleep Endoscopy (DISE) is a sedation procedure that uses IV medication to create a sleep-like state similar to Stage 2 sleep, a normal stage of sleep when the muscles of the throat begin to relax.

Once this sleep state is achieved, a thin scope is passed through the nasal passages to examine the throat. This allows the surgical team to observe how the airway behaves during sleep and identify the location and severity of airway collapse.

Because DISE evaluates the airway during a sleep-like state, it provides information about both anatomy and physiology and can help guide treatment planning.

The information from a sleep study, CT scan, and DISE helps determine where the throat collapses during sleep and identify the factors contributing to airway blockage.

Using these findings, the surgical team can develop a treatment plan designed to address the specific areas of collapse and obstruction.