About eight years ago I had my dentist make a bite guard because I was grinding my teeth at night. I was very happy with it, but I noticed recently that I was starting to grind holes into the very hard plastic. I asked a friend who is a dentist what she thought of the night guards you could buy over the counter and she said that while they aren't as good as the ones she makes, they do the trick and since I'm on a tight budget these days, it was definitely something I should consider. So I went and bought the Doctor's Night Guard and went through the process of molding it to my teeth. I climbed into bed with it in my mouth and a few minutes later, I had to take it out. I just couldn't do it because my mouth was way too small. Sure, it says one size fits all, but apparently it's not made for small mouths. So if you have a small mouth, don't buy this because you'll end up having to take it out and will be left with some very sore jaw muscles!