Evaluation of the accuracy of determining optimal activation force of canine retractor springs by software

Introduction: The ability to accurately measure forces produced by orthodontic appliances during orthodontic treatment is desirable. The aim of the present study was to compare forces measured by mechanical formulae designed with a software program and those experimentally measured by a dynamometer to find a scientific way to determine the exact amount of activation needed for applying a force within the optimum range.Materials and Methods: In this in vitro study, at first the formulation of force applied by canine retractor spring was determined with the aid of mechanical sciences. To confirm the accuracy of the formulation, 50 springs made of different wire diameters, working arm lengths, different number and diameters of helices and with different designs, the number of which had been determined by a pilot group, were examined and the results obtained from the formulation and dynamometer were compared. Paired t-test was used for statistical analysis (α = 0.05).Results: The difference between the measurements made by the dynamometer (mean = 65) and those determined by the formulation (mean = 65.88) was 0.8842 gr, which was statistically significant (p value = 0.003).Conclusion: Under the limitations of the present study, it appears formulations can be used to determine the amount of spring activation and the software designed for such a purpose facilitates the use of the formulation. Key words: Force system, Orthodontic appliances, Software.