What Does ‘Edgewise’ Mean
- The original edgewise archwire was made of gold alloy, rolled into a rectangular shape.
- It measured 0.022 x 0.028 inches, or sometimes 0.022 x 0.025 inches, with squared corners.
- The edgewise archwire was named because, unlike the ribbon archwire, it would be seated horizontally with its long dimension being the buccolingual (i.e. rotated by 90° to the orientation it had with the ribbon arch appliance), thereby seating into the bracket slot with its narrower edge, hence the term “edgewise”.
What Does ‘Preadjusted’ Mean
Standard Edgewise Appliance: Required significant wire-bending skills to control tooth angulation.
Holdaway’s Technique (1952): Proposed placing brackets at slightly angled positions to reduce wire-bending and achieve desired tooth angulation more efficiently.
The Three Orders of Tooth Movement
1.First-order tooth movement (In-Out):
Teeth crowns vary in buccolingual thickness.
Horizontal/radial first-order bends compensate for this difference.
2.Second-order tooth movement (Tip):
Teeth exhibit varying mesiodistal angulation.
Second-order bends in the archwire correct tooth angulation.
3.Third-order tooth movement (Torque):
Correct buccolingual inclination of each tooth is essential.
Third-order (torquing) bends in the archwire achieve this.
Torque applies rotational force to the tooth through the engagement of the archwire and bracket slot.
Note: Torque is derived from Latin “torquere,” meaning to twist, and refers to the rotational force applied to the tooth.
What Does ‘Preadjusted’ Mean
Standard Edgewise Appliance: Required significant wire-bending skills to control tooth angulation.
Holdaway’s Technique (1952): Proposed placing brackets at slightly angled positions to reduce wire-bending and achieve desired tooth angulation more efficiently.
The Three Orders of Tooth Movement
First-order tooth movement (In-Out):
Teeth crowns vary in buccolingual thickness.
Horizontal/radial first-order bends compensate for this difference.
Second-order tooth movement (Tip):
Teeth exhibit varying mesiodistal angulation.
Second-order bends in the archwire correct tooth angulation.
Third-order tooth movement (Torque):
Correct buccolingual inclination of each tooth is essential.
Third-order (torquing) bends in the archwire achieve this.
Torque applies rotational force to the tooth through the engagement of the archwire and bracket slot.
Note: Torque is derived from Latin “torquere,” meaning to twist, and refers to the rotational force applied to the tooth.
