It is fairly normal for hockey players to lose teeth. It is less common for hockey goalies to be among them, though. They're the only guys in the sport who will wear full facial protection for the entirety of their hockey careers.
However, as Ben Bishop of the Tampa Bay Lightning found out Tuesday night, sometimes the goalie mask doesn't completely do its job.
During the second period of the Lightning's game against the Toronto Maple Leafs, Bishop caught a high, hard shot from Peter Holland right off his goalie cage. He immediately went down to the ice.