It’s hard to say what causes the wearing off of the effect. It could be the result of an anatomical alteration, but it could also be resulting from material fatigue of the somnipax anti-snoring mouth guard. The best thing to do is to send an E-mail to our customer service centre with an image of your somnipax shield Anti-Snoring Mouth Guard (service@somnishop.co.uk). Then we can take a closer look at it and help you.