If you are experiencing lines on your face when waking up or forehead dents it is most likely caused from over tightening your mask. Loosen the straps as you should not have to over tighten to prevent leaks. If your mask is not sealing properly it either is not the correct size or needs to be replaced. There are also newer masks available that do not have forehead supports as well as different mask accessories to work with your mask. These include mask liners or cozy pads to go over mask straps.