A mouth guard is a piece of oral protective equipment, frequently used by athletes that participate in sports such as boxing, football, hockey or other sports where injury to the mouth and teeth may occur. People who grind their teeth while asleep may also wear a mouth guard. Made of resilient, rubbery plastic, a mouth guard fits around the teeth and follows the jawline of the wearer. This serves as a shock absorber around the teeth and gums and between the jaws. Mouth guards are custom-fit to the mouth of each person by softening them in boiling water.
Purchase a mouth guard that is the proper size for your mouth. Place the mouth guard in a small metal or glass bowl that will withstand boiling water. Prepare a bowl of cold water to immerse the mouth guard in later.
Boil some water and fill the bowl with it to completely cover the mouth guard. Allow the mouth guard to sit for 20 to 30 seconds, until it softens.
Remove the mouth guard from the boiling water with the fork and dip it in cold water for three seconds. This allows the guard to cool just enough so you can fit it around your teeth and gums.
Bite down on the mouth guard. Seal your lips and suck on the mouth guard hard for 45 seconds to one minute. During this time, press the guard against your teeth and gums with your tongue and lips while it cools. This will help form the device.
Open your mouth and check the guard for fit. If the mouth guard fits well, leave it in place for another two minutes, then remove the mouth guard.
If the impressions are not deep enough or the mouth guard is improperly aligned or loose, reheat the mouth guard and repeat steps 2 and 5.
When the shape of the mouth guard fits properly, immerse it in cold water to set the plastic permanently.