A device (1) for the mandibular advancement, a process for making an appliance(10) for the mandibular advancementand the appliance realized； the device comprises a first engagement element(2) associable with the lower dental arch or mandible and asecond engagement element (3) associable with the upper dental arch ormaxilla, said engagement elements (2, 3) being provided witha first inclined engagement surface (21) and a second inclined engagementsurface (31) for determining said mandibular advancement；the first engagement element (2) comprises a core (22) covered by a coveringbody (23) provided with a pocket adapted to the housingof said core (22), the second engagement element (3) comprising an orthodonticscrew (33) adapted to determine the displacement ofthe second inclined plane (31), the core (22) having an inclined portion (221B) destined to define, in cooperation with the respectivecovering, said first inclined engagement surface (21).
