[Biomechanics or orthodontic treatment of tooth rotation]

The correction of dental rotation associated with a lingual or buccal version is possible to obtain with the action of a force system that is: consistent or inconsistent. The authors investigated a mandibular right second bicuspid rotated positively with its distal surface to the buccal. They decided to correct this rotation by using a consistent force system formed by a force and a moment applied to center of resistance (long axis in the occlusal view) and in lingual direction. It's possible to obtain in a consistent force system with the utilization of a straight wire or a "cantilever beam". The Authors decided to correct this rotation by using a cantilever beam of 017x025 wire with a vertical loop hooked over a heavier 021x025 wire between the first and the second molars. With an inconsistent system it's necessary to include a box loop so it is possible to make a variation and insert the wire from teh anterior or posterior just to obtain a consistent force system.