Hockey
Close contact and flying pucks are all dangerous to the pearly whites. Wearing a mouthguard protects the teeth, gums and tongue.
Skiing and Snowboarding
Flying down the slopes with the risk of running into someone, hitting the hard-packed snow or crashing into a tree are all risky for teeth. Wearing a mouthguard while skiing or snowboarding can help prevent damage in the event of a facial injury.
Basketball and Wrestling
These winter sports are sans snow but pose all the risks for a facial injury. Close contact with opponents can result in knocking out a tooth (a flying elbow is a definite possibility). Wear a mouthguard to reduce the risk.