Sleep apnoea


obstructive sleep apnoea


T


he upper airway in humans has multiple purposes: speech, swallowing and breathing. It comprises soft tissue and muscle, but, importantly in


the context of this article, does not have hard, bony tissue to prevent the muscle or soft tissue from compressing or collapsing. The collapsible part of the upper airway,


which spans the hard palate to the larynx, can change shape and close briefly to allow for speech and swallowing. It is the collapse of this upper airway during sleep that precipitates an apnoeac event.


Sleep-disordered breathing The upper airway collapses during sleep when there is no compensatory input to the motor neurones of the upper airway dilator muscles – mostly the genioglossus and tensor palati muscles. How often the person compensates for these collapses determines the rate at which the cycle repeats. When airflow is blocked for ı0 seconds or more, it is called apnoea (or apnea) meaning suspension of breathing. Hypopnoea (or hypopnea) is a partial collapse of the airway that results in an airflow reduction of greater than 50 per cent for ı0 seconds or more (Figure ı). Although several neurotransmitters and


neuromodulators have been identified as contributing to the regulation of the upper airway opening, there has been little progress finding a medicine to prevent its collapse. Burwell, Robin, Waley and Bickelmann studied the pathophysiology of sleep


Continued » Pathophysiology of snoring and


An increasing number of dentists are managing sleep-related breathing disorders as a result of awareness of the role they can play in improving the quality of life of patients who suffer with this debilitating disease. What are its causes and consequences?


The mechanism of airway obstruction Fig 1


Ireland’s Dental magazine 37


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