A properly fitted mouthguard must be protective, comfortable, resilient, tear resistant, odorless, tasteless, not bulky, cause minimal interference to speaking and breathing, and (possibly the most important criteria) have excellent retention, fit, and sufficient thickness in critical areas.

Unfortunately, the word "mouthguard" is universal and generic, and includes a large range and variety of products, from "over the counter" models bought at the sporting goods stores to professionally manufactured and dentist prescribed custom made mouthguards.

 The stock mouthguard, available at most sporting good stores, come in limited sizes (usually small, medium, and large) and are the least expensive and least protective. The prices range approximately from, $3 to $25. These protectors are ready to be used without any further preparation or in some cases boiled for a custom fit. They are bulky and have limited retention, and therefore must be held in place by constantly biting down. This interferes with speech and breathing, making the stock mouthguard the least acceptable and least protective. This type of mouthguard is often altered and cut by the athlete in an attempt to make it more comfortable, further reducing the protective properties of the mouthguard. [smouthguard.com: "After 2 weeks of use the guard is worn out"] Custom Mouth Guard: The custom made mouthguards fulfill all the criteria for adaptation, retention, comfort, and stability of material. They interfere the least with speaking and studies have shown that the custom made mouthguard has virtually no effect on breathing. They are also available in a variety of colors.