used to, but as has been said, once you get used to it, many sleep better with if than without it. There are a few who just won't tolerate anything in their mouth, but I have only come across a few.

The initial tightness will get better as the teeth move back into place and the tightness goes away. It will come back if you don't wear it for a long period of time.

I always recommend a custom guard for the reasons that were stated before. A one size fits all mouth guard just isn't going to work well. Soft, rubbery night guards are worse because you clench and grind even more and some people get headaches and increased jaw pain. Also, the OTC night guards don't take into account how your teeth should fit together for your jaw to be comfortable, while a hard, acrylic night guard can be adjusted to make your teeth fit together where your jaw is most comfortable and relaxed.

Having said that, I realize not all patients are going to spend the money for a custom night guard, so I tell them to go ahead and try the OTC ones with the warning that it can aggravate things and cause tmj issues or even a change in bite. Many come back for a custom one.