What is sleep apnoea?
An apnoea episode is defined as the absence of breath for 10 seconds or more. Simply put, someone is considered to suffer from sleep apnoea if they stop breathing like this 30 or more times during a normal 7 hour sleep period. Typically a person may have as many as 300 apnoeic episodes per night and some of them may last up to 120 seconds at a time.
There are three basic classifications of sleep apnoea: central, obstructive and mixed.
In central apnoea, the trouble seems to lie in the part of the brain that controls breathing during sleep. The brain appears to forget to send the necessary instructions to the breathing muscles. In this type of apnoea the airway stays open, while the chest muscles and diaphragm stop working. Falling levels of oxygen sound the alarm in the brain, causing the sleeper to waken and start breathing. Since the airway remains open, the sleeper may not snore.
Obstructive Sleep Apnoea
During sleep, muscles, including muscles necessary for breathing, relax much more than they ever do during waking hours. In most people, this normal process causes no problems; sleep is a time of rest. However, for some people, muscles relax excessively, compromising breathing and making sleep a time of danger.
Specifically, in obstructive sleep apnoea, the muscles of the throat and tongue relax and sag, obstructing the airway and making breathing laboured and noisy. As pressure to breathe builds, muscles of the diaphragm and chest work harder. The effort is akin to sipping a drink through a floppy straw: the greater the effort the more the walls collapse. Collapse of the airway walls eventually blocks breathing entirely. When breathing stops, a listener hears the snoring broken by a pause until the sleeper gasps for air and awakens, but so briefly and incompletely, that s/he usually does not remember doing so in the morning.
When these interruptions of breathing occur, oxygen in the blood drops causing your blood pressure to rise and your heart to work harder. Over time, these episodes of apnoea can even be associated with hypertension, stroke, initiation of a gastroesophageal reflex, frequent nocturnal voiding, susceptibility to atherosclerosis, and stroke or cardiopulmonary problems that can lead to sudden death.
Mixed apnoea is a combination of central and obstructive apnoea usually beginning with a central episode being immediately followed by an obstructive one. When this is seen, the obstructive component is treated first. This usually eliminates the problem but when it does not, re-evaluating the patient for a central component will have to be done. People who have mixed apnoea generally snore.
Many treatment methods have been tried over the years to treat snoring and obstructive sleep apnoea. Regardless of the technique used, most people benefit by following a few general measures. Some of the guidelines are:
- Maintain a healthy weight
- Get regular exercise
- Avoid alcohol prior to going to sleep
- Avoid sleeping pills
- Only take over the counter medications that have been approved by your physician
- Sleep on your side.
Nasal CPAP (Continuous positive airway pressure) – The patient wears a mask over his/her nose and the airway is kept open by using a compressor that gently forces air through the nasal passages.
Surgery – Sometimes physical abnormalities like enlarged tonsils, nasal polyps, a deviated nasal septum or malformations of the jaw or palate can contribute to snoring and apnoea. There are numerous surgical techniques which are available to help correct these defects.
Dental Appliance Therapy
Dental appliances have been shown to be very successful in the treatment of snoring and are also regularly used in both the diagnosis and treatment of obstructive apnoea. Dental appliances offer several advantages over other therapy choices. They are inexpensive, non-invasive, easy to fabricate, reversible, and quite well accepted by patients.
The basic indications for dental sleep appliances are to treat primary snoring and mild to moderate obstructive sleeps apnoea. Appliances are particularly appropriate for those patients who cannot tolerate CPAP. When surgery is contraindicated or the patient is unwilling to go through a surgical procedure, appliance therapy may also be appropriate.
Only a specially trained dentist can properly select the appliance that is right for you.
A Sleep Quiz
Answering these simple questions may be the first step to a restful night’s sleep for you and your family. The problems listed here may appear suddenly or emerge over many years. It is possible that you are not even aware of them. We recommend that you discuss these questions with your family members and co-workers, as they may be the first to recognise these signs.
- I have been told that I snore.
- I have been told that I snore loudly, every night, in all positions.
- I have been told that I stop breathing while I sleep.
- I have jolted awake gasping for breath during the night.
- After a full night’s sleep, I still wake up feeling tired.
- I fall asleep at inappropriate times, for example, at work or behind the wheel of a car.
- I have trouble concentrating.
- I have become unusually forgetful.
- People say, or I feel, I have become uncharacteristically irritable, anxious or depressed.
- I often wake up with a headache.
- I have high blood pressure.
- I am overweight.
- I seem to have lost my sex drive.
IF YOU CAN ANSWER YES TO ANY OF THESE STATEMENTS YOU SHOULD ASK YOUR DENTIST OR PHYSICIAN ABOUR SNORING AND SLEEP APNOEA.