A removable device (100, 200) for advancing a lower jaw (20) relative to an upper jaw (10) in a mouth. An upper member (110, 210) is configured to be retained on an upper jaw buccal segment (15), positioned to the rear of the mouth, extending back towards the upper molars (14) of the upper jaw buccal segment, the upper member comprising one or more retaining members (114, 214) for securing the upper member removably on the upper jaw by engaging with one or more upper teeth (12, 13, 14) of the upper jaw buccal segment. A lower member (120, 220) is arranged to be retained on a lower jaw buccal segment (25) and inner lingual surface of the mandible (300), positioned to the rear of the mouth, extending back towards the lower molars (24) of the lower jaw buccal segment. The lower member comprises one or more retaining members (224) for securing the lower member removably on the lower jaw by engaging with one or more lower teeth (22, 23, 24) of the lower jaw buccal segment and a plate configured to lie on a portion of the lingual surface of the mandible, extending from the buccal teeth over the gingival margin onto the attached gingivae and attached oral mucosa. The upper and lower members are configured to be retained entirely within a first half of the mouth and a linking member (130, 230) is configured to connect the upper member to the lower member such that the lower jaw is advanced to and retained at a predetermined minimum distance relative to the upper jaw when the upper member is secured on the upper jaw and the lower member is secured on the lower jaw.La présente invention concerne un dispositif amovible (100, 200) pour faire avancer une mâchoire inférieure (20) par rapport à une mâchoire supérieure (10) dans une bouche. Un élément supérieur (110, 210) est configuré pour être retenu sur un segment buccal (15) de mâchoire supérieure, positionné à larrière de la bouche, sétendant en arrière vers les molaires supérieures (14) du segment buccal de mâchoire supérieur
