CauseLots of people experience this when they start using a SleepPro. A SleepPro starter appliance puts the pressure of your jaw trying to move back into place overnight onto your front teeth. However, it could also be caused by your jaw being pushed too far forward.SolutionMost people find it usually goes away after using the mouthpiece for a couple of weeks. Try remoulding the mouthpiece with your jaw not so far forward. If the problem persists consider upgrading to a SleepPro custom, which spreads the load more evenly.