Back in the day, me and my bud had a 1 on 1 game. There was no hit rule, just fall back and regroup. Anyways, i was behind a large tree being shot at from about 15 yards away.
A bb bounced off the tree and hit me in the mouth, end result being a chipped tooth. Thankfully not a very large chip, didnt even need to fill it in.
This was Through a thin layer of shemagh AND a closed mouth.
now i usually wear a mesh mask.