Head Indentation?

I have been using an F10 full ask for 2 years.
Just noticed I have an indentation on the top of my head from the strap.....is thus normal?

Thanks
Marilyn

Get a padacheek strap cover.

Make sure your straps are not too tight.

If I loosen the straps even a bit I get hissing out of the mask

It's a soft tissue thing. Your skull isn't indented despite it feeling like it is. I can pretty much guarantee you that if you got an x-ray of your skull there would be no evidence of a groove anywhere in the bone.

Adding some padding via strap covers like from padacheek.com will help diffuse the pressure of the strap which will help with the soft tissue displacement.
Either that or try a different mask that has different strap placement.

It's really no different than when I get a strap mark on my cheek when I lay on it for a prolonged period of time.
Some people just get that soft tissue/fluid displacement easier than others and lasts longer for some people than it does for others.

Some people just get that soft tissue/fluid displacement easier than others and lasts longer for some people than it does for others.

Yes I have little grooves above my ears from my glasses. They have to be tight because there is not much nose for them to perch on and I hate when they slide off my nose. When big glasses were in in the 80's they rested on my cheeks....