Mouth guards are a common accessory of those with sleep apnea, and it is very easy to understand how they do, in fact, work. When someone with the disorder lies down to go to sleep, their tongue and throat muscles relax, and not enough space is available for air to travel through. This is what causes the snoring. Every couple of minutes, the brain must wake the body enough for it to actively take a breath. This leads to the fatigue experienced during the day. A mouth guard pushes forward the jaw, and sometimes the tongue, so that the muscles do not close up, and your body is able to breath normally again.
So if your dentist recommends a mouth guard or any other sleep apnea appliances, give it a shot. Chances are, it will work for you and allow you to have a good night’s sleep.