used to wear lower face mesh, works well and probably wont steam up. As for gum shields. I've seen people having their lower teeth shot out, as most only wear upper ones, this would not protect them. Also they are meant to take a blow from a fist to the face, not a 6mm at ~1j. Also my close friend always plays with mask, except ONCE when his girlfriend joined in and he lent it to her and played only with goggles. After a long process, lots of pain and money, he now has a fake tooth. He also have quit airsoft as he feels really uncomfortable with it even when masked. Is it really worth the risk? :/
rofl