An orthodontic screw and a set of elements for forming an orthodontic or orthopedic appliance for dentistry, as well as a method for making an orthodontic or orthopedic appliance for dentistry. The orthodontic screw includes two bodies connected by positioning elements designed to allow the distance between the bodies to be adjusted; the bodies have a seat adapted to receive a portion of a connection structure associable with the orthodontic screw for its connection to the teeth of a dental arch; the seat has a groove formed on an external surface of the bodies, so that said portion of said connection structure can be inserted in the seat through a displacement orthogonal to the same seat.