Sleep – Snoring

Unfortunately, tooth grinding, or gnashing, affects between 30 and 40 million Americans. What's more, this condition, also known as “bruxism,” is unintentional or involuntary. That's why most people who have it usually do it in their sleep.
How do I know if I need a night guard? If I do need one, what kind should I get? What are the differences between ones from the drug store and the one I would get from my dentist?