There are many reasons that one may need an appliance to wear as they are sleeping. Damaging behaviors such as Bruxism: Grinding of Teeth at Night, Clenching, or other jaw movements that may damage the dentition or dental restorations. Nightguards are recommended to protect against damaging forces on the surfaces and edges of high risk patients, or those already demonstrating wear patterns on their teeth.
Sleeping appliances that reduce snoring by repositioning the jaw are also made. There are many different varieties of mandibular repositioner appliances and a different appliances may be recommended for different situations.