Orthodontic force prediction model of T-loop closing spring based on dynamic resistance model.

Malocclusion has been seriously endangering human oral function. The most effective and mature therapy is orthodontic treatment. But the relationship between the shape of the T-loop and the orthodontic force is unclear, and the precise mathematical model has not been established. In this article, the dynamic orthodontic force prediction model of the T-loop was established by analyzing the treatment process of the T-loop. The model was based on the dynamic resistance model of waxy dental jaw, the theory of beam deformation, and the deformation characteristics of the T-loop. In the experimental process, 11 kinds of orthodontic archwires were used as experimental samples, including 2 kinds of common archwire materials, 7 kinds of cross-sectional sizes, and 10 kinds of clearance distances. The T-loop was put into the extraction space and immersed in 75°C constant temperature water for 2 min. And the experimental data were measured and collected by the dynamic force measuring device. The experimental results show that the cross-sectional size and the clearance distance are positively correlated with the orthodontic force. The influence of the clearance distance on the orthodontic force is greater than that of the cross-section size. The deviation rates between the experimental values of orthodontic force and the theoretical values are between 1.10% and 9.09%, which verifies the accuracy of the dynamic orthodontic force prediction model. The model can predict the orthodontic force, improve the treatment effect, shorten the treatment cycle, and provide reference and guidance for orthodontists to carry out orthodontic treatment safely and effectively.