When you are first fitted with a nightguard, it may be a good idea to spend an hour or two the first day wearing it while you are awake. This will help you get used to the feel of the guard being in place. Getting used to the guard in your mouth can feel normal right away or may take months to get used to. Having a custom night guard can usually minimize this process as the guard is made to fit your teeth. The greatest problem with adjustments typically comes from stock night guards.