Intra-oral appliances are removable devices used in the oral cavity during sleep, repositioning the jaw, tongue and other structures, to promote increased air passage. Recommended for patients with snoring, in mild and moderate cases of obstructive sleep apnea syndrome (OSAS) and upper airway resistance syndrome. They can also be used in severe cases of OSAS, where there is intolerance to the use of CPAP, lack of adherence to CPAP treatment or as a short-term replacement therapy (in case of travel, for example)..