Application of a new viscoelastic finite element method model and analysis of miniscrew-supported hybrid hyrax treatment

Abstract

Introduction: In this study, we aimed to assess the ability of a new viscoelastic finite element method model to accurately simulate rapid palatal expansion with a miniscrew-supported hybrid hyrax appliance. Methods: A female patient received 3-dimensional craniofacial imaging with computed tomography at 2 times: before expansion and immediately after expansion, with the latter serving as a reference model for the analysis. A novel approach was applied to the finite element method model to improve simulation of the viscoelastic properties of osseous tissue. Results: The resulting finite element method model was a suitable approximation of the clinical situation and adequately simulated the forced expansion of the midpalatal suture. Specifically, it demonstrated that the hybrid hyrax appliance delivered a force via the 2 mini-implants at the center of resistance of the nasomaxillary complex. Conclusions: The newly developed model provided a suitable simulation of the clinical effects of the hybrid hyrax appliance, which proved to be a suitable device for rapid palatal expansion. (Am J Orthod Dentofacial Orthop 2013;143:426-35)