A mouth guard is a plastic type device usually fitted to the upper jaw to 
cover the upper teeth. Mouth guards are used to protect against bruising 
of the lips and cheeks, injuries to the cheeks and tongue, and fractures 
of the teeth and jaws. Although a mouth guard may not prevent an injury 
used will usually greatly reduce the severity.

Types of mouth guards:
There are three basic types of mouth guards available.
The Type I mouth guard is referred to as a stock (ready to wear) mouth guard available in most sporting goods stores. It is ready to wear and the least expensive type, but at the same time offering the least amount of protection from injury. It requires no fitting but is often difficult to wear and uncomfortable. It must be held in place by clinching the teeth together, which can interfere with breathing. For these reasons the stock mouth guard is not recommended for those with fixed dental appliances and orthodontic braces. The Type II mouth guard is directly formed to the upper teeth after being softened in boiling water. This type of mouth guard can be comfortable and stay in place easily if it is properly adapted to the teeth. Too often, it is not properly fitted when done by the athlete or someone not experienced in making the appliance. The Type III mouth guard is custom-fitted over a dental model of the upper teeth. While this type of mouth guard must be fitted by a dentist and is the most expensive to make, it provides the most protection from injury. This mouth guard shows the best retention and is the type used in college and professional sports as well as many high school programs.
What is a good mouth guard? The ideal mouth guard has a number of characteristics. Protection – must provide maximum protection to the teeth, lips, tongue and gums by cushioning the shock from a blow to the mouth or head. Retention – must be retentive and remain in place by being closely adapted to the teeth. It should be pliable and constructed of resilient material that is bite and tear resistant. It should be comfortable to wear, cover all the teeth in one jaw, usually the upper. It should be removable and easily taken in and out of the mouth. Function – should not interfere with breathing or speech. The mouth guard should be odorless and tasteless to maximize the comfort of wearing the protector. When should a mouth guard be worn? Mouth guards should be worn during all practices and games for recreational and sports activities. Removable appliances (partial and complete dentures) should be removed during most sports activities. If there are areas of the mouth without teeth it is best to have a custom made mouth guard that will adapt to these areas of the mouth for the greatest protection and stability. If there are fixed appliances that cannot be removed it is even more important to wear a mouth guard. How do I take care of my mouth guard?
A mouth guard can be cleaned in warm soapy water and rinsed with cold water. When not in use the mouth guard should be kept in a plastic case. The mouth guard should be examined regularly and if it becomes damaged or does not fit tightly be replaced. NEVER wear someone else’s mouth guard.