Paul Plascyk, General Dentist
(According to the American Academy of Sleep Medicine
(these are physicians not dentists), snoring and most sleep apnea can be
effectively treated by oral appliances made by properly trained dentists.)
Snoring (also known as upper airway resistance syndrome): A rough rattling sound made on inspiration (breathing in) during sleep by vibration of the soft palate (the back of the roof of the mouth) and the uvula (the prominent structure dangling down at the back of the mouth).

http://hcd2.bupa.co.uk/fact_sheets/html/snoring.html
Prevelance of snoring: 30%-50% of the US population snore at one time or another, some significantly.
Consequences of snoring: Snoring can cause great distress for the bed partners of snorers, leading to 80% of couples to end up sleeping in different rooms. Snoring can be a sign of obstructive sleep apnea which is a life-threatening condition.
Sleep Apnea: Sleep apnea is a extremely serious chronic condition where the affected person repeatedly stops breathing during sleep. These episodes last 10 seconds or more and cause oxygen levels in the blood to drop. It can be caused by obstruction of the upper airway, resulting in obstructive sleep apnea, or by a failure of the brain to initiate a breath, called central sleep apnea. Sleep apnea can cause and worsen other medical conditions, including hypertension, heart failure, stroke and diabetes.
Obstructive Sleep Apnea (OSA): This is the most common type of sleep apnea. In obstructive sleep apnea, the muscles of the soft palate around the base of the tongue and the uvula relax, obstructing the airway.