A set of orthodontic brackets is provided in combination with an archwire extending over an arc when fitted to the set of orthodontic brackets. The archwire has at least one radius of curvature over the length of its arc, and each one of said brackets in the set has an archwire slot. Each slot has at least one surface supporting the archwire which is contoured to have a radius of curvature that matches the radius of curvature along the arc of the archwire at that point. A round archwire is preferred and the archwire slots may be formed as tubular channels to provide better torque action for the archwire.