July 31, 2019
Snoring is one of many significant symptoms of obstructive sleep apnoea. However snoring alone does not always mean you have sleep apnoea.
When we sleep lying on our back the tongue will fall to the back of the throat and obstruct the airway. This leads to the sound of snoring. (See figures 1 and 2) In some individuals snoring can also happen whilst they are on their side.
This may be due to a constricted airway from the muscles of the soft palate and its associated structures not maintaining proper tone. The presence of large tonsils and adenoids may also cause some obstruction.
Figure 1. Cross section of airway showing an unobstructed airway. Note the position of the tongue away from the back of the throat.
Figure 2. Cross section of the airway which is blocked due to the tongue collapsing over the airway.
If an adult has at least 7-8 hours of sleep a night there is no cause for feeling sleepy during the day. Nodding off to sleep whilst reading or watching TV is not normal. Some adults can do with less sleep and feel refreshed when they wake. If you feel unrefreshed in the morning, sleepy throughout the day and find focusing on task difficult, with poor concentration, despite adequate sleep, you may have sleep apnoea. Gasping for air whilst asleep is also another sign of apnoea. This is often noticed by the bed partner.
The only way sleep disorders are diagnosed is by consulting a sleep physician. They will order a sleep study and after analysing the sleep data recommend the necessary management of the condition.
There are different levels of sleep study. These include hospital based studies to take home kits. The hospital based studies are the most accurate and considered the most reliable. However some forms of take home kits (See figure 3) are also accepted as reliable and accurate. The sleep physician will be the authority on prescribing the most relevant type of study based on the clinical examination.
Figure 3. This picture shows the take home test kit being worn.
The severity of sleep apnoea is dependant on the number of times the person stops breathing over a prescribed period. The greater number of episodes of such events the more severe the condition and therefore the symptoms.
There are currently 2 main types of treatment which have strong scientific evidence to show effectiveness and validity for use. This includes CPAP (continuous positive airway pressure)-see figure 4 or a Mandibular advancement Splint (MAS) or appliance (see figure 5 and 6).
The former is considered the gold standard in managing sleep apnoea of moderate to severe intensity. It is a mask which one wears over the nose and mouth and air is pumped into the lungs whilst you sleep.
A Mandibular advancement splint (MAS) is a device worn in the mouth to hold the lower jaw in a protruded position. This appliance props the tongue forwards preventing it from dropping to the back of the throat. In doing so the airway is maintained and vital oxygen reaches the lungs.
Figure 4. CPAP mask being worn.
The MAS is now considered a viable alternative to the use of CPAP machines in treating moderate to severe sleep apnoea. Current studies are showing that using a MAS can reduce the severity of apnoea and therefore have a positive impact on sufferers of this condition. In the event that an individual cannot tolerate the use of CPAP, sleep physicians are currently recommending the use of MAS.
Figure 5. Dorsal fin MAS on a stone model.
Figure 6. Dorsal fin MAS.
There are many types of MAS on the market. Some are sold over the counter at retail outlets. But a MAS is not just a piece of plastic placed in the mouth it is in fact a form of oral appliance therapy.
The medical literature recommends that for a MAS to work correctly with limited side effects, it needs to be fitted by a dentist and the appliance itself must be custom fitted and adjustable. Adjustable appliances are devices which will protrude the lower jaw forward at a controlled rate. It will also allow for the degree of protrusion to be reversed.
Sleep apnoea is a dangerous condition which has wide ranging effects on individuals. The increased risk of cardiovascular disease, depression, and diabetes are some of the main medical conditions which can be associated with sleep apnoea. Diagnosis and management is crucial in order to prevent problems to general health in the long term.
In the next issue we will be discussing root canal treatment and the benefits of keeping your natural teeth for as long as possible.
Thank you for reading.
Dr Roland Chong