The invention relates to an orthodontic tool for opening a self-ligating bracket, having a body (10) which carries on its end a tappet (12) for displacing a clamp (5) of the bracket out of its closed position and into its open position, an annular groove (13) being situated between the tappet and the body, in which an upper edge of the bracket engages in displacement of the clamp (5) out of its closed position and into its open position between the tappet (12) and the body (10) for axial positioning of tappet (12) with respect to the bracket to be opened. The invention also relates to a system having such a tool and a self-ligating bracket.