Curvature versus v-bends in a group B titanium T-loop spring.

Area of Science:

• Orthodontics
• Biomaterials Science
• Mechanical Engineering

Background:

• Titanium T-loop springs (TTLSs) are utilized in orthodontics for controlled tooth movement.
• Understanding the force systems of different preactivation methods is crucial for optimizing treatment outcomes.
• Titanium molybdenum alloy (TMA) wire is a common material for orthodontic appliances due to its properties.

Purpose of the Study:

• To compare the force systems of curvature-preactivated and V-bend-preactivated TTLSs.
• To analyze the horizontal and vertical forces, as well as moment-to-force (MF) ratios, generated by these TTLS designs.
• To evaluate the suitability of these TTLS configurations for orthodontic anchorage.

Main Methods:

• TTLSs made of 0.017 x 0.025-inch TMA wire were designed using LOOP software.
• Curvature and V-bend preactivation methods were employed.
• Loops were activated by 7 mm, with forces and moments recorded during 0.5 mm deactivation increments.
• Standardized bracket height (23 mm) and angulation (0 degrees) were maintained.

Main Results:

• Curvature-preactivated TTLSs produced horizontal forces from 34–456 gF; V-bend TTLSs produced 54–517 gF.
• The preactivated V-bend TTLS showed slightly greater force decrease (33 gF) per activation step compared to the curvature TTLS (30 gF).
• Moment-to-force (MF) ratios were consistently higher for curvature-preactivated TTLSs (5.8–38.8 mm) than for V-bend TTLSs (4.7–28.3 mm).

Conclusions:

• Both curvature and V-bend preactivated TTLSs exhibit symmetrical moments, suitable for group B anchorage.
• Curvature-preactivated TTLSs deliver lower horizontal forces and higher MF ratios compared to V-bend preactivated TTLSs.
• The choice between curvature and V-bend preactivation depends on the desired force system and anchorage control in orthodontic treatment.