Related Experiment Video
Updated: Aug 9, 2026

Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
The effects of torque control spurs in twin-block appliances
1Bristol Dental Hospital and Dental School, Bristol, UK; Countess of Chester Hospital, Chester, UK.
Abstract:
The study compared the effects of torque control spurs on upper incisor retroclination and extrusion with two designs of a twin-block functional appliance in Class II/1 cases. The two designs were also compared with respect to anchorage loss in the lower arch and for patient compliance rates. Consecutively started cases were chosen - 90 patients with a design incorporating a labial bow (CTB group) and 110 with upper incisor 'torquing' spurs (STB group) and used to calculate failure rates. Thirty consecutive patients with satisfactory records from each group were analysed cephalometrically. The STB group experienced substantially less upper incisor retroclination, reduced upper incisor extrusion and slightly more favourable mandibular growth. The labial movement of lower incisors and the patient compliance were not significantly different in the two groups. Overall, 82.5% of patients fully reduced their overjet with 9% failing to reduce the overjet below 6 mm.Fig. 1f
Related Concept Videos
Torque
Torque can be considered as the rotational counterpart to force. Since forces change the translational...
Net Torque Calculations
Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Torque Free Motion
Generator Voltage Control
Turbine-Governor Control

