1. Obstructive Sleep Apnea(OSA) - Diagnosis

Diagnosis

The diagnosis for OSA can only be made by a medical practitioner such as a sleep specialist or an ear-nose and throat specialist. Dentists who have proper training will work with their medical colleagues to help screen potential OSA sufferers and advise them to see their primary care physician for further investigation.

In 2006, the American Academy of Sleep Medicine (medical sleep specialists) issued guidelines stating that for patients with mild to moderate OSA, the oral appliance was the number one treatment option. These guidelines also indicated that the oral appliance was a viable option for patients who did not respond to weight loss or have tried CPAP and were not able to tolerate it. For serious sleep disorder, there are three treatment options:

  1. Oral appliance
  2. CPAP(Continuous Positive Air Pressure)
  3. Surgery

The diagnosis for OSA is made using an Apnea-Hypopnea Index (AHI). This requires an overnight sleep study in a sleep clinic. The sleep study is called Polysomnogram (PSG).

Apnea

Apnea is a condition in which the soft tissues, at the back of the throat, completely closes off the airway so that the air cannot flow into the lungs. This usually happens in the deeper part of the sleep cycle when the muscles relax. The airway blockage reduces the amount of oxygen reaching the brain and the body. This results in the brain alerting the muscles in the airway to tighten up and unblock the air way. This also co-insides with bruxism or teeth grinding which is the oral component of bracing or tightening to open up the airway. This excessive grinding can cause problems in the temporomandibular joint (TMJ). As the airway opens, a loud gasp or snort is heard. They patient may sit up or move violently before falling back to a light sleep. This repeated blocking and un-blocking of the airway can prevent the patient from achieving deep, restorative sleep.

In the morning the patient usually has no memory of these incidents.

There has to be a cessation of air flow at the mouth and nose for more than 10 seconds to be considered an apnea episode. The severity is categorized by the frequency of apnea episodes:

Mild: 5 to 15 episodes per hour
Moderate: 15 to 30 episodes per hour
Severe: more than 30 episodes per hour

Apnea can last from 10 to 120 seconds, resulting in at least partial awakening. A severe apnea patient may have as many as 300 episodes per night.