What type of mouth guard is best?

A mouth guard protects the teeth and jaw of athletes who might sustain an impact to the head or face while playing sports. While there is no question that a custom made mouth guard will fit better and be more comfortable, a pre-made mouth guard may work for some people. The mouthguard must be protective, comfortable, resilient, tear resistant, odorless, tasteless, not bulky, cause minimal interference to speaking and breathing, and have excellent retention, fit, and sufficient thickness in critical areas.