The invention relates to an intraoral orthosis comprising a first shell (10) and a second shell (20), said shells (10, 20) being connected to one another by an adjustable connection device. The adjustable connection device comprises two notched tabs (31) which are disposed on each side of one of the shells (10, 20) respectively, each notched tab (31) adjustably cooperating with a respective adjustment housing (32) disposed on each side of the other shell (20, 10). The adjustment housings (32) are moulded as one piece with the aforementioned other shell (20, 10) and each adjustment housing (32) is connected to said other shell (20, 10) by a folding support structure (34).
