After being fitted with a mouth guard called the Thorn ton Adjustible Positioner, or Tap, Bennett was astonished by the difference. From the first night, I no longer felt sleepy during the day. The change was so instant, says Harvey, and the silence so eerie, that she used to check that he was still breathing. Bennett also has sleep apnea, a condition in which the airway is so obstructed that the sufferer intermit tently stops breathing. This can happen regularly during the night for around 10 seconds at a time and, in very severe cases, last up to 40 seconds, many times an hour.
Sufferers jerk awake with unnerving grunts and gasps when oxygen in the brain dips to a low level.
Frank Govan, chairman of the British Sleep Apnoea Trust and a sufferer himself, says the condition affects about four in every 1,000 people and can be life-threat ening. The BDA points out that most people with sleep apnoea snore, but not all snorers have sleep apnoea. It is important for dentists to make the dis tinction and to work in conjunc tion with a sleep clinic where specialists can identify the anatomical cause and degree of blockage. People with severe sleep apnoea sometimes wear a mask which pushes oxygen into the lungs under slightly raised pressure. This works, but there are people who find the masks cumbersome and claustrophobic and who are converting to mouth guards.