Abstract: An intraoral orthosis including a first shell and a second shell. The shells are connected together by an adjustable connection device, the adjustable connection device including two notched tabs that are arranged respectively on either side of one of the shells, each notched tab co-operating in adjustable manner with a respective adjustment housing, arranged correspondingly on either side of the other of the shells, the adjustment housings being molded integrally with the other shell, each adjustment housing being connected to the other shell by a foldable support structure.