Allahyar Geramy - DDS, MSc Associate Professor, Orthodontics Department, Tehran University of Medical Sciences(TUMS)

Aim: Introduction of new bracket designs in market and use with a range of inciso-apical dimension and base thickness arises a question in mind as "Is it necessary to standardize various bracket bases from torque delivery efficiency?" Materials and Methods: Two bracket bases of different incio-apical dimension (۳ and ۶ mm.) and also two different base thicknesses (۱.۶ and ۳.۵ mm.) were modeled and moments were applied. All displacements along a defined incio-apical path were monitored to be evaluated. Results and Conclusion: No difference was found between the displacements along the defined path in each phase of study. In this way, it was concluded that torque delivery of different brackets is not related to their base size (inciso-apical) and dimenson which is in complete agreement and confirmation of the principle of free vectors. (IJO ۲۰۰۶; ۱: ۷۱ - ۷۴)

Bracket Design, Base Thickness, Base Dimensions, Torque Delivery, finite element method, FEM