Hi, I was glad to find this thread as there seems to be hardly anything written about this. After about five years of using my CPAP machine I discovered a horizontal line on my head exactly where the strap ran. I compared the shape of my head to the shape of my head just a few years before I began using the machine by looking at pictures. It became very obvious that the strap must have caused the deformity as there had been nothing at all before I started wearing the mask!
