Australasian Dental Practice 2001; Vol 12 (2): 44
by Julian Hodges ba.dms.
A few weeks ago, a large Manly Ferry ran onto the rocks in Sydney Harbour because the helmsman had fallen asleep at the wheel. Fortunately, no one was killed.
In a recent study nearly a quarter of motor vehicle accidents, many of them fatal, were attributed to sleep disorders.
For these and numerous clinical and morbidity reasons, there is a rapidly growing awareness of the social and economic costs of snoring and obstructive sleep apnoea (OSA).
The problem may be bigger than we realise. One report estimates that amongst the middle aged, 93% of women and 82% of men with moderate or severe OSA have not been clinically diagnosed.
It is recognised that the treatment of snoring and OSA is mainly a medical problem but most doctors have not been trained to handle sleep disorders. In medical schools, little time is spent on the subject. The result is a shortage of facilities and specialists in this field.
The standard for diagnosis and treatment is a polysomnographic study and the use of a continuous positive airway pressure machine (CPAP). The continuing growth in the share price of Resimed and the national awards it has received, confirms the boom in the sleep disorder business and the efficacy of CPAP machines.
But, the costs are high, testing facilities are severely limited and many patients, in spite of the serious consequences of their condition, will not tolerate a CPAP machine in the long term. One study shows that within 90 days 40% to 50% of patients stop using them.
An alternative is to fit mandibular advancement devices or splints (MAD or MAS) which evidently are preferred by 95% of patients. Test results on the newer adjustable devices show that MAD’s can be as effective as constant positive airway pressure particularly with patients who have mild or moderate sleep apnoea.
There is nothing new about the efficacy of advancing the mandible. Virtually every healthcare professional and anyone who has done a basic CPR course understands its function in correcting a collapse of the airway.
With the realisation that dentistry has an important role in the treatment of sleep disordered breathing, we can expect a rush of papers, claims, research studies and courses dedicated to the subject. We can also expect a rapid rise in the number of devices that are available and dentists will need to be able to review with balance, the inevitable persuasive marketing proposals that will be put to them.
These are my recommendations having been involved in the development, training and production of mandibular advancement devices for the past four years.
- No single device will suit or be effective for all patients.
- Within a narrow range, most adjustable devices are as effective as each other.
- To gain continuous long-term patient compliance it is necessary to fit a highly comfortable device.
- Movement – Lateral and vertical movement is necessary for comfort, speech and to aid the avoidance of possible TMJ problems.
- Design – The design and position of some components may hinder comfort.
- Materials – Hard, inflexible materials are less comfortable.
- Fit – The more accurate the fit, the greater the comfort.
- Volume – Smaller devices are less intrusive
- The device should be adjustable without having to be returned to a laboratory.
As with all splints, bruxers can be destructive. Larger, harder, processed splints may not always solve the problem when softer more flexible materials may succeed.
Finally, effectiveness with mouth breathers should be considered. The configuration of some designs, Herbst for instance, exacerbate snoring by pulling the mandible away from the desired protrusive position. Others that have pivot points on the upper canines, pull the mandible protrusively thereby counteracting the negative effects of mouth breathing.