Comparison of the force systems of 3 appliances on palatally impacted canines

IntroductionAlthough much imaging research has focused on the localization and the management of impacted canines, optimal biomechanics for successful recovery are not clear. The purpose of this research was to compare the 3 mechanics—Kilroy spring, elastic chain, and steel ligature wire—used for the management of impacted canines by quantifying the 6 components of force systems involved with each system.MethodsA dentoform model was modified to simulate a palatally impacted canine. Load cells installed in the dentoform simultaneously measured the 3 forces (Fx, Fy, Fz) and the 3 moments (Tx, Ty, Tz) on the canine. The activation range and force system attenuation as the canine moved were also measured. The results were analyzed statistically.ResultsThe Kilroy spring has an activation range of 13 mm (Fz), the elastic chain has an activation range of 12 mm (Fz), and the ligature wire has an activation range of 1 mm (Fz). The full range of the elastic chain cannot be used because of its limited elastic behavior.ConclusionsThe 3-dimensional force system for canine recovery mechanics can be quantified by using these devices. Quantification of the force system provides critical information for appropriate selection of an optimal appliance.