Abstract: A fixing device (1; 20) for orthodontic devices comprising; a screw (2; 44) complete with an operating head (3; 42) with longitudinal slots (4; 45) for the insertion of orthodontic devices and a threaded shank (5) designed to be screwed inside the patient's oral cavity; means for fixing orthodontic devices contained inside the operating head (3; 42). The fixing means comprise a shaped body (6) engaging inside a recess (7; 47) in the operating head (3; 42) and revolvable inside the recess (7; 47). The shaped body (6) has a through opening (8) for the insertion of the orthodontic device and opposing means that anchor the orthodontic device to the operating head (3; 42) when the shaped body (6) is rotated inside the recess (7; 47) after the orthodontic device has been inserted in the through opening (8) and in the longitudinal slots (4; 45).