[Biomechanical testing of the new torque-segmented arch (TSA)]

Area of Science:

• Orthodontics
• Biomaterials Engineering
• Dental Mechanics

Background:

• Conventional orthodontic arch wires can lead to undesirable side effects such as anterior tooth extrusion and excessive anchorage loss.
• Bending torque into traditional wires often results in complex adjustments and potential complications.
• Superelastic materials offer unique properties for controlled force delivery in orthodontic applications.

Purpose of the Study:

• To introduce and evaluate novel torque-segmented arch wires designed for improved torque control and reduced side effects.
• To compare the clinical performance and biomechanical outcomes of torque-segmented arch wires against conventional steel wires.
• To assess the potential for minimizing anterior tooth resorption and anchorage demands during orthodontic treatment.

Main Methods:

• Development of torque-segmented arch wires featuring a superelastic anterior component and steel lateral components connected by a crimped connector.
• Clinical application of the torque-segmented arch wires in orthodontic treatment, requiring specific bending techniques for optimal results.
• Comparative analysis of biomechanical forces, including extrusive and protrusive forces on anterior teeth, and molar anchorage moments, versus conventional 0.016 x 0.022 inch steel wires.

Main Results:

• Torque-segmented arch wires demonstrate considerably smaller extrusive and protrusive forces on anterior teeth, reducing anchorage demands.
• These segmented wires result in diminished or no tooth resorption compared to conventional steel wires, even with significant torque application.
• The superelastic anterior component provides constant moments, allowing application in various anterior tooth positions and simplifying treatment adjustments.

Conclusions:

• Torque-segmented arch wires offer a significant advancement in orthodontic treatment by reducing undesirable side effects associated with torque application.
• The controlled force delivery system minimizes anterior tooth extrusion, protrusive forces, and potential root resorption, enhancing patient outcomes.
• These novel arch wires are compatible with both standard edgewise and straight-wire techniques, offering versatility and potentially reducing the need for frequent radiographic monitoring.