Retraction of canines using bonded tube-brackets

Investigations using a Force Analyser were carried out to test the characteristics of retractor springs fitted to a removable appliance and designed for insertion into a tube-bracket, bonded to the buccal surface of a canine. The retractors were shown to produce a counter-rotation couple when activated on the typodont. This type of canine retraction was then used clinically, and was found to produce less distal tilting than is noted with the single-point contact of a cantilever spring. Some spontaneous reduction in overjet was found to occur in each case of a small series. Possible mechanisms to account for this effect are discussed.