A mouthguard is a protective device for the mouth that covers the teeth and gums to prevent and reduce injury to the teeth, arches, lips and gums. An effective mouthguard is like a crash helmet for teeth and jaws. It also prevents the jaws coming together fully, thereby reducing the risk of jaw joint injuries and concussion. A mouthguard is most often used to prevent injury in contact sports, as a treatment for bruxism or TMD, or as part of certain dental procedures, such as tooth bleaching or sleep apnea treatment. Depending on application, it may also be called a mouth protector, mouth piece, gumshield, gumguard, nightguard, occlusal splint, bite splint, or bite plane. The dentists who specialise in sports dentistry fabricate mouthguards.