Measurement of orthodontic bracket tie wing elastic and plastic deformation by arch wire torque expression utilizing an optical image correlation technique

• Published in: Journal of dental biomechanics Vol. 2010; no. 1
• Main Authors: Lacoursiere, Ryan A, Nobes, David S, Homeniuk, Darren L N, Carey, Jason P, Badawi, Hisham H, Major, Paul W
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 2010; SAGE-Hindawi Access to Research
• Subjects: Orthodontic appliances; Properties; Wire; Canada
• ISSN: 1758-7360; 1758-7360
• DOI: 10.4061/2010/397037

Orthodontic lingual root movement (torque) is an important aspect of treatment biomechanics and is typically achieved by torsion of a rectangular wire within the orthodontic bracket slot which introduces a force couple. The magnitude of the force moment achieved by wire torsion may be influenced by deformation of the orthodontic bracket. A device utilizing an optical image correlation technique has been developed to accurately quantify bracket slot dimensional changes during application of wire torsion. Simultaneous torque moment magnitude, degrees of wire twist, and bracket slot dimension data can be gathered. Bracket tie wing elastic deformation when loaded was demonstrated and plastic deformation was also observed with a single rotation of the wire.