The dilemma of functional therapy: the new EFA to do or not to do?

• Main Authors: Omnia A. Elhiny, Mohamed I. El-Anwar
• Format: Article
• Language: English
• Published: SpringerOpen 2018-11-01
• Series: Bulletin of the National Research Centre
• Subjects: Finite element analysis; Fixed functional appliances; Biomechanical effects; Mandibular growth
• Online Access: http://link.springer.com/article/10.1186/s42269-018-0024-3

Abstract Objectives This finite element analysis was conducted to study the effects produced by a new fixed functional appliance (EFA; Elhiny functional appliance) and hence predict its clinical effectiveness. Materials/methods Under ANSYS environment, a simplified 2D finite element model was prepared for this study. The models simulated a clinical situation where the mandible was positioned forward via a new fixed functional appliance design. The models’ components were created on a commercial CAD/CAM package then imported to finite element software. Pushing load of 2 N was applied along the appliance longitudinal direction. Results The mandible showed downward and forward deformation in the X and Y directions with the highest deformation at the symphysis and lower border with a total deformation of 80 μm. There was little deformation in the maxilla. The highest strain results were at the condyle, both compressive and tensile in the X and Y directions with a total of 1520 micro strain behind the condyle. The strain in the mandibular tooth bearing area was around zero and in the maxillary tooth bearing area ranged from − 9 to 16.6 micro strain. Conclusions Within the limitations of this finite element analysis, it could be predicted that the new appliance (EFA) produces pure functional skeletal results with absolutely no dentoalveolar effects, which provides the opportunity for observing significant skeletal changes.