Mixed Martial Arts, or MMA, is a contact sport in no uncertain terms. As is the case with all contact sports, participants are wise to wear protective gear, particularly if they value their dentition. Although participation in the sport calls for a minimal amount of MMA equipment(basically, shorts, gloves and for women, a sports bra is all that is allowed), head and mouth protectors are highly recommended.
Of course, with the explosive growth in the popularity of MMA in the US and other parts of the world, numerous manufacturers (including one best known for its motorcycling wear) have begun producing thousands of product offerings which range from cheap and poorly made to expensive, high-quality items that will last for years. It pays to do some comparison shopping. Read some of the online MMA forums to find out what other fighters have to say, and above all, not be afraid to spend a few bucks for something that is durable and will furnish the best protection. After all, even at $100, a good mouth guard is far less expensive than dental implants (which can run has much as $3000 for a single tooth).
There are two types of MMA mouthguards available; the single and the double. A single mouth guard furnishes protection only for the upper jaw, and is the type most commonly worn by MMA fighters. The double mouth guard offers a great deal more protection, but has the drawback of restricting respiration, which can out one at a distinct disadvantage during such a high-exertion workout. This is the reason that most MMA fighters opt for the single mouth guard.
Nonetheless, it is strongly recommended that you choose the double type. Aside from the extra protection and padding, a double mouth guard will also help to isolate and stabilize the lower jaw. This means that when you take a blow to your chin, you will run less risk of serious TMJ and head injury; because the upper and lower jaws are locked in place, the force of the blow is absorbed by the neck muscles instead of the skull.
When choosing mouthguards, look for one made from at least two materials; a hard outer shell and soft, gel-like inner surface. It is also important not to bite down with too much force when fitting it to your own bite; otherwise, you risk deforming the inner padding to the point that it will no longer furnish sufficient protection.
MMA headgear is similar to those used by boxers when training. A decent leather helmet, well padded inside and out with extra cushioning for the ears, jaw and cheekbones is the best choice. Again, plan on spending between $80 and $100 because the cheap "bargain brands" won't do you much good in the ring.