A mouthpiece is a device that fits into the mouth and is used for various purposes, including playing musical instruments, sports, and dental applications. In music, mouthpieces are essential for instruments like trumpets and saxophones, allowing musicians to produce sound. In sports, particularly in boxing and football, mouthpieces protect the teeth and jaw from injury during physical activity. In dentistry, mouthpieces can be custom-made to help with issues like bruxism, where individuals grind their teeth at night. They can also be used for orthodontic treatments, helping to align teeth and improve overall oral health.