Document Type

Patent

Patent Number

US Patent 4,037,324

Patent agency

United States Patent and Trademark Office

Publication Date

7-26-1977

Assignee

University of Iowa Research Foundation (Iowa City, IA, US)

Application Number

362,578

Date Filed

1973-05-21

Total Pages

8 pages

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. When the wire exerts tooth-moving forces by being subjected to torsional or flexural stresses, the alloy also includes cobalt substituted for nickel on an atom-for atom basis so that the composition is TiNi.935 Co.065.

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URL

https://ir.uiowa.edu/patents/10