In the edgewise system, how did Angle reorient the bracket slot?

In the edgewise system, how did Angle reorient the bracket slot?

• A. From horizontal to vertical.
• B. From vertical to diagonal.
• C. From diagonal to horizontal.
• D. From vertical to horizontal.

Answer: (D)

The key idea is how the bracket slot orientation affects how the rectangular wire sits and how its shape can create controlled tooth movements. By changing the slot from vertical to horizontal, Angle made the slot run left-right across the tooth so a rectangular wire can seat edgewise with its flat faces properly aligned in the slot. This orientation lets the wire engage more effectively and express torque, giving predictable three-dimensional control of tooth movements. If the slot stayed vertical (or were changed in a way that didn’t align with the wire’s geometry), the wire wouldn’t seat and transmit torque as reliably. Hence, reorienting from vertical to horizontal best explains the edgewise system’s development.

The key idea is how the bracket slot orientation affects how the rectangular wire sits and how its shape can create controlled tooth movements. By changing the slot from vertical to horizontal, Angle made the slot run left-right across the tooth so a rectangular wire can seat edgewise with its flat faces properly aligned in the slot. This orientation lets the wire engage more effectively and express torque, giving predictable three-dimensional control of tooth movements. If the slot stayed vertical (or were changed in a way that didn’t align with the wire’s geometry), the wire wouldn’t seat and transmit torque as reliably. Hence, reorienting from vertical to horizontal best explains the edgewise system’s development.