Affiliations: Department of Mechanical Engineering, School of Engineering and Technology, and Department of Oral Facial Development, School of Dentistry, Indiana University – Purdue University at Indianapolis, 723 West Michigan St., Indianapolis, IN 46202-5132, USA | Department of Mechanical Engineering, School of Engineering and Technology, Indiana University – Purdue University at Indianapolis, IN, USA | Department of Oral Facial Development, School of Dentistry, and Department of Mechanical Engineering, School of Engineering and Technology, Indiana University – Purdue University at Indianapolis, IN, USA | Department of Oral Facial Development, School of Dentistry, Indiana University – Purdue University at Indianapolis, IN, USA
Note: [] Current address: Department of Precision Instrument, Manufacture Engineering Institute, Tsinghai University, Beijing 100084, P.R. China.
Abstract: Large deformation non-linear finite element models of T, V, L and B (Baldwin) orthodontic springs were developed and experimentally validated. Spring stiffnesses and moment/force ratios were computed. Compared to the T loop, under horizontal activation, the V loop was half as stiff, the L loop was equal, and the B spring was 10% as stiff, The moment/force ratio was 30% higher in the V configuration, while the B spring was less by 95%. The asymmetric L loop exerted a moment/force ratio that was 30% on the one side, but 180% in the opposite direction on the other side. With vertical activation, also compared to the T spring, the horizontal stiffnesses were 500% (V), 150% (L), and 30% (B). The concomitant vertical stiffnesses were 100%, 50% and 25%. The vertically activated moment/force ratios were nearly equal in the four springs. Experiments validated these FEM calculations.
