Abstract: Mesial-distal slippage of an orthodontic archwire is deterred by manufacturing a parabolic archwire with a bend at its vertex. The bend has a height incapable of entering the wire-receiving slots of the brackets on a patient's teeth.

Abstract: Orthodontic movement of malaligned teeth is performed by attaching to the teeth a wire which has properties useful in orthodontics. When the anticipated use of the wire involves torsional and flexural stresses, the wire is a single strand of a material having a higher elastic limit and a lower elastic modulus than an 18-8 stainless steel wire of identical cross-section. The invention also contemplates the use of wires which demonstrate a plastic memory which causes them to return to a preset shape or length after being deformed and then heated. For example, longitudinally shrinkable wires are either attached to teeth for closing the spaces therebetween or are used to draw a tooth toward a fixed reference member such as a rigid archwire spaced from the tooth. The mechanical memory of the wire may also tend to restore it to a preset shape upon heating in order to level or torque malposed teeth. The disclosed wires are formed of Nitinol alloy which is a known near-stoichiometric alloy of nickel and titanium.