DO NOT EVER practice takedowns without a mouthpiece in. DO NOT ever do any stand up striking without a mouthpiece in. According to the American Dental Association, an athlete is 60 times more likely to have a tooth injury when not wearing a protective mouth guard. Studies have linked almost a third of dental injuries to sports-related activities. And in these other sports, the tooth injuries are accidents. In our game the other guy is trying to rattle your teeth.

If you lose a tooth and it is not properly preserved or replanted, you face lifetime dental costs of $10,000 - $15,000 per tooth, hours of rapture in the dentist's chair, and increased development of other dental problems such as periodontal disease. I blocked a high kick with my face once, had a tooth break in half, and then swallowed it; this is a bad deal. If I had a mouthpiece in, all I would have had was a pretty good headache.

In Addition to protecting against having a tooth broken, knocked out, or displaced from its socket, a mouthpiece can prevent:
•Lacerations to lip, cheek, and chin.
•Fractures of the facial bones especially the check bones and mandible which can cause facial deformity.
•Possible permanent injury to the jaw joints.
•Concussions. Concussions have to be avoided as anyone who does this sport is shy a few brain cells to begin with.
•Cerebral hemorrhages.
•Incidents of unconsciousness.
•Neck injuries by helping to avoid situations where the lower jaw gets jammed into the upper jaw.
•Preventing laceration and bruising of the lips and cheeks.

Anyone who trains standing or striking without a mouthpiece receives automatic entry into the Asshole Hall of Fame.

Mouthpieces (also known as  a mouthguard, mouth protector, mouth piece, or if you speak English with an English accent a gumshield) comes in three types:
1.    Stock mouth protectors are preformed and come ready to wear. They are inexpensive and can be bought at most sporting good stores and department stores. However, they suck. Little can be done to adjust their fit, they are bulky and make breathing and talking difficult and they provide little or no protection. In an interesting historical aside, the guy who invented this one also holds a patent for Ejector Seats for Helicopters.
2.    Boil and bite mouth protectors offer a better fit than stock mouth protectors. The "boil and bite" mouth guard is made from thermoplastic material. It is placed in hot water to soften, briefly cooled, then placed in the mouth and shaped around the teeth using finger and tongue pressure. These can range in cost from a buck to fifty bucks or more.
3.    Custom mouthguards are sports mouth protectors that are individually made for an fighter. A well-designed custom mouthguard provides the greatest level of protection for an fighter as compared to a boil and bite. The fit and comfort of a custom mouthguard is excellent. The more comfortable and unobtrusive a mouthguard is the greater the likelihood that you will wear it at all times. Additionally, the retention of a custom guard is superior and therefore produce less interference with speech and breathing than other types of guards.  These guards are usually obtained from the athlete's dentist or a company providing dental laboratory services. Cost $100 to $300.

An further point of consideration is a single or double mouthpiece. The latter is a single solid mouth guard into which both your top and bottom teeth fit. There is generally a breathing hole in the middle. While providing an additional degree of safety, many fighters find them uncomfortable and hard to breathe through. Many fighters don’t, too.

We looked at over 100 mouthpieces, and offer both the simplest boil and bite, or a fancy boil and bite. The main purpose of a mouthpiece is to give you something to bite down on, either accomplishes that admirably. The more expensive boil and bites do offer real advantages. If you want to buy a custom mouthpiece, ask your dentist or do what I did and buy one from http://www.customguards.com.

Once you have a mouthpiece, in order for it to work, you have to wear it. Towards that end, you have to get used to it. Some initially people get a gag reflex from one. To overcome that, do your road work with it in. In a couple of weeks, you will be used to it.

Another impediment is having one, not feeling like you have to puke when it is in, but just not wearing it. As an Armenian friend of mine says “Life is tough kid, and it’s a lot tougher when you’re stupid."

A last impediment to not using a mouthpiece is losing it. Every week in every gym everywhere finds a few lost mouthguards lying around. There are few things less pleasant in the fight game than finding your mouthpiece, putting it in your mouth, and realizing it belongs to someone else. The effect is basically kissing a dude.

The surest way to not lose your mouthpiece is to get a case that is attachable, and attach it to the outside of your gym bag. Doing this will save you a lot of hassle.

To care for your mouth guard:
•Rinse your mouth guard with cold water before putting it in.
•Regularly rinse with a mouth rinse and/or clean it with a toothbrush. Leaving it overnight in mouth rinse leaves is tasting fresh.
•Place the mouth guard in a firm, perforated container to store or transport it. This permits air circulation and helps to prevent damage. If the container attaches to the outside of your gym bag, it becomes far harder to lose.
•Protect the mouth guard from high temperatures – such as hot water, hot surfaces, or direct sunlight – to minimize distorting its shape.
•Occasionally check the mouth guard for general wear. If you find holes or tears in it or if it becomes loose or causes discomfort, replace it.