Abstract
The goal of this investigation was to adapt and incorporate a nonlinear viscoelastic material model representative of the midpalatal suture’s viscoelastic nature into finite element analysis simulations of maxillary expansion treatment. Step-wise displacements were applied to a partial skull geometry to simulate treatment using an expansion screw appliance. Four simulation cases were considered for the midpalatal and intermaxillary sutures: 1. Neglecting suture tissue; 2. Linear elastic properties; 3. Viscoelastic properties; 4. A fused intermaxillary and viscoelastic midpalatal suture. Results from simulations indicated that removal of suture tissue and inclusion of viscoelastic properties resulted in the same maxillary displacement following 29 activations of 0.125 mm applied directly to the maxilla; however, assuming a fused intermaxillary suture significantly changed maxillary displacement patterns. Initial stress results within the suture complex were significantly influenced by the inclusion of suture viscoelasticity as compared to linear elastic properties. The presented study demonstrates successful incorporation of suture viscoelasticity into finite element analysis simulations of maxillary expansion treatment, and elucidates the appropriateness of various suture material property assumptions depending desired research outcomes.
Highlights
Maxillary expansion (ME) has been in use since 18601 to mechanically widen the upper jaw, maxilla, of patients to aid in alleviating malocclusion of the dental arch[2], nasal respiratory restrictions, and sleep apnea[3,4]
Before incorporating any viscoelastic material properties in a partial skull model for ME treatment simulation, the Rectilinear Test Geometry (RTG) was used to ensure that the user-defined properties worked as expected on a simplified and well-understood geometry
The analytical model developed in previous work (Eq (1)) was based on experimental data, and comparison of the Finite Element Analysis (FEA) model to past results using the same formulation would verify the user-defined viscoelastic material model has been established correctly in ANSYS
Summary
Maxillary expansion (ME) has been in use since 18601 to mechanically widen the upper jaw, maxilla, of patients to aid in alleviating malocclusion of the dental arch[2], nasal respiratory restrictions, and sleep apnea[3,4]. Finite Element Analysis (FEA) has been used previously to study the mechanics of ME treatment from several perspectives such as understanding stress distribution throughout the skull or the amount of maxillary widening that may be expected for a given simulated protocol[7]. Investigating this research question would elucidate how MPS/IMS material model assignment influences ME treatment simulation and provide a better understanding of how to assign suture properties based on the specific study aims. Romanyk et al characterized the bulk material behavior of the midsagittal suture in New Zealand white rabbits using a 1D stress relaxation material model given as (Eq (1))[13]:. This model characterizes the relaxation stress, σR, as a function of the initial suture strain, (weeks). The model was determined using analytical methods to interrelate the nonlinear stress εr0eRla, xaantdiotnimfuen, ctwtion in Eq (1) to a creep strain function fit to the New Zealand white rabbit experimental creep strain data
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
