Yes, I've seen it in the mirror, actually. Rarely wore it in public though, although it happened, which was not such a big case as HG was common where I went to primary and junior high (late 80s, early 90s) - during that period I believe I saw at least 20 other kids wearing HG at school, most of them much more frequent than me (I only wore it to catch up on hours prior to appointments at the orthodontist's and would never have worn it in public hadn't it been such a common sight).
Interesting fact, though, there were two orthodontists back where I am from, and you could see who were patients where as one (mine) used metal brackets on the lower jaw and clear on the upper, while the other one used clear ones on both. I never saw anyone else having my orthodontist wearing HG in public (except, of course, at the orthodontist's office). Don't know if he was old-fashioned, or what. It is true, though, that after I moved town I've never seen any kids with HG.