OSAS - a new treatment responsibility

June 1, 1997
Since snoring may signal the presence of sleep apnea, this life-threatening condition should be the focus of treatment.

Since snoring may signal the presence of sleep apnea, this life-threatening condition should be the focus of treatment.

Trisha E. O`Hehir, RDH, BS

Here`s a new acronym for you: OSAS. According to the figures, 20 million people in North America suffer from this problem. With an incidence level like that, you are sure to know someone with OSAS -Obstructive Sleep Apnea Syndrome. Snoring often is a symptom. Do you know someone that snores?

At a recent meeting in Vancouver, British Columbia, I attended a Luncheon for Learning entitled: "Oral Appliances for the Treatment of Snoring." Our luncheon host was Dr. Alan A. Lowe, chair of the Department of Orthodontics at the University of British Columbia. As an expert in this field, Dr. Lowe has published numerous research papers on OSAS, treated hundreds of patients, and submitted several patents for oral appliances. He was instrumental in establishing the standards in this area through the American Sleep Disorders Association. He covered a vast amount of information in an hour and succeeded in piquing my interest in the subject. Since you couldn`t join us for lunch, I`ll give you a quick overview of the material.

Snoring occurs when the tongue moves back, narrowing the airway. Rapid movement of air through the passages causes vibrations - snoring. Although snoring may not be life threatening, it can be annoying for both the sufferer and his/her bed partner.

OSAS involves the tongue being sucked back against the posterior wall of the pharynx, completely cutting off breathing. This interruption in breathing - an apnea - usually results in the person waking slightly and then resuming normal breathing until it happens again. If breathing is cut off for 10 seconds or more and occurs more than five times per hour, the person generally will suffer symptoms of sleep deprivation the next day.

The Apnea Index (AI) is the number of apnea occurring per hour during sleep. This index can be approximated by the bed partner when the snoring keeps him/her awake. It can be measured more accurately in a sleep laboratory, where blood-oxygen levels, breathing, and sleep stages also can be monitored. This type of testing is called "overnight polysom-nography."

Apnea refers to the complete absence of breathing for periods of at least 10 seconds. Hypopnea refers to abnormal reductions in breathing for at least 10 seconds. When breathing is reduced, a wheezing sound results. The combined index, the Apnea-Hypopnea Index (AHI) counts the incidence of both apnea and hypopnea during an hour of sleep.

Controversy exists about what constitutes a "normal" index score. At this time, a score of five or less is considered normal for the Apnea Index, and a score of 10 or less has been established as the norm for the Apnea-Hypopnea Index.

Obstructive Sleep Apnea can be life threatening, if the reduction in oxygen is sufficient to lead to hypertension, ischemic heart disease, or stroke. Snoring is considered a risk factor for these conditions. Although not all snorers have sleep apnea, it is a cardinal symptom of OSAS.

Patients with OSAS generally are middle-aged, overweight males. The first-choice treatment involves wearing a mask during sleep called CPAP (nasal continuous, positive airway pressure). Medications have been used, as have surgical procedures, including tracheotomy, reduction of the soft palate, and removal or reduction of the uvula. Laser-assisted uvulopalatopharyngoplasty is a recent addition to the list. Oral appliances are considerably less expensive, and users experience fewer side effects than with surgery or medications.

Are you getting questions from patients about oral appliances for snoring? As early as 1902, oral appliances were constructed to treat snoring. Today, 55 appliances are on the market. As of January 1999, the Food and Drug Administra-tion (FDA) had approved 32 appliances for snoring and only 14 appliances to treat both snoring and OSA. As you can see from these numbers, many of these appliances have not received FDA approval. Only seven are adjustable and only three have undergone controlled clinical trials.

The appliances move the mandible forward, hold the tongue forward, or both.

Adjustability allows for incremental steps in moving the mandible forward. Changes in a nonadjustable appliance often require the fabrication of a new one. Recent advances in appliance fabrication have led to a combination of desirable qualities, including: adjustability, lateral and vertical movements of the jaw, and increased retention of the appliance during sleep. Advances in this field also have led to better-defined steps in treatment.

The take-home message on this topic? Never recommend an appliance for a patient without first getting a medical evaluation by the patient?s attending physician or a sleep specialist. Reducing or eliminating snoring, without treating the apnea, could be fatal for the patient! Since snoring may signal the presence of sleep apnea, this life-threatening condition should be the primary concern and focus of treatment, rather than the snoring itself.

Trisha E. O`Hehir, RDH, BS, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics. The Web site for Perio Reports is www.perioreports.com. Her e-mail address is trisha@perioreports. com.