Abstract: In dental treatment for fitting a wire piece onto the teeth and/or jaw, a patient is subjected to repeated bending and in some cases twisting of the wire and some arrangement for completing the treatment, with whose help the bending and twisting process takes place automatically by machinery. Accordingly, next the data about the shape of the teeth and/or jaw is ascertained and put into an electronic computer, where this data is converted into control data. The wire piece will then be put into a bending machine with separately controlled stepping drives for advancing the wire, twisting and bending, whose drive through the command of the computer will automatically be controlled. The bending machine comprises essentially an advancing means, a torsion work piece of two grippers relatively rotatable with each other and a bending work piece with a moving bending edge substantially perpendicular to the wire axis.