Torque prescription for maxillary central incisor according to MBT in degrees is:

 # Torque prescription for maxillary central incisor according to MBT in degrees is:

A. 17

B. 10

C. -7

D. 0

The correct answer is A. 17.

Torque in orthodontics refers to the buccopalatal crown-root inclination of a tooth. To implement torque, larger dimensional archwires are inserted and engaged into brackets. This generates an activating force as the wire is manipulated into the bracket slot. Torque is not directly “in the wire.” Instead, it results from torsion in an archwire when it interacts with a bracket slot. When the wire twists compared to the bracket slot, it creates a couple (a rotational force) that affects the tooth’s inclination. Torque is not related to the angle of the bracket slot or the axial inclination of the tooth. In orthodontic treatment, torque control is often required, especially for maxillary incisors. Proper torque helps achieve an ideal inter-incisal angle, adequate incisor contact, and sagittal adjustment of the dentition for an ideal occlusion. The goal is to achieve the desired buccopalatal inclination of the crowns and roots. The MBT system is a popular pre-adjusted edgewise appliance system.

In the MBT system, torque prescription is based on the specific bracket design and the desired tooth movement. Orthodontists select brackets with predetermined torque values to achieve the desired crown-root inclination. The torque values are typically printed on the bracket prescription chart provided by the manufacturer. According to MBT, torque prescription for maxillary central incisor in degrees is 17 degrees.