Background: To evaluate load and stress distribution on Delaire facemask (FM) during maxillary protraction in class III growing patients by means of finite element analysis (FEA). A three-dimensional geometry of a Delaire FM was reconstructed from the original CAD 3D prototype, using software package (ANSYS 5.7). FM presented forehead and chin supports and stainless steel framework characterized by two lateral vertical bars connected to a crossbar with two pawls for elastic attachment. Two traction intensities (7.8 and 9.8 N) were applied on the FM pawls along three different downward inclined directions with respect to the occlusal plane (0 degrees, 30 degrees, or 50 degrees, respectively). Resulting stresses and deformations were then tested through the von Mises yield criterion in order to underline the FM wear performance.Results: The analysis showed that higher stresses and deformations are mostly related to axial forces of 9.8 N rather than 7.8 N. Stresses also progressively increased with increasing downward force inclinations (0 degrees, 30 degrees, and 50 degrees with respect to the occlusal plane). The overall tensions were inferior to the limit of the elastic behavior (yield point) characterizing the material they are applied on. Thus, the FM structure absorbed the load applied with an elastic deformation of the lateral and horizontal bars.Conclusions: Resulting stresses and deformations were directly proportional to protraction load amounts and to increasing downward inclination of forces. In all tested conditions, protraction forces were not able to determine plastic deformation on FM structure compromising its performance and efficiency.

Gazzani, F., Pavoni, C., Giancotti, A., Cozza, P., Lione, R. (2018). Facemask performance during maxillary protraction: a finite element analysis (FEA) evaluation of load and stress distribution on Delaire facemask. PROGRESS IN ORTHODONTICS, 19(1), 21 [10.1186/s40510-018-0217-1].

Facemask performance during maxillary protraction: a finite element analysis (FEA) evaluation of load and stress distribution on Delaire facemask

Pavoni, Chiara;Giancotti, Aldo;Cozza, Paola;Lione, Roberta
2018-07-09

Abstract

Background: To evaluate load and stress distribution on Delaire facemask (FM) during maxillary protraction in class III growing patients by means of finite element analysis (FEA). A three-dimensional geometry of a Delaire FM was reconstructed from the original CAD 3D prototype, using software package (ANSYS 5.7). FM presented forehead and chin supports and stainless steel framework characterized by two lateral vertical bars connected to a crossbar with two pawls for elastic attachment. Two traction intensities (7.8 and 9.8 N) were applied on the FM pawls along three different downward inclined directions with respect to the occlusal plane (0 degrees, 30 degrees, or 50 degrees, respectively). Resulting stresses and deformations were then tested through the von Mises yield criterion in order to underline the FM wear performance.Results: The analysis showed that higher stresses and deformations are mostly related to axial forces of 9.8 N rather than 7.8 N. Stresses also progressively increased with increasing downward force inclinations (0 degrees, 30 degrees, and 50 degrees with respect to the occlusal plane). The overall tensions were inferior to the limit of the elastic behavior (yield point) characterizing the material they are applied on. Thus, the FM structure absorbed the load applied with an elastic deformation of the lateral and horizontal bars.Conclusions: Resulting stresses and deformations were directly proportional to protraction load amounts and to increasing downward inclination of forces. In all tested conditions, protraction forces were not able to determine plastic deformation on FM structure compromising its performance and efficiency.
9-lug-2018
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore MED/28 - MALATTIE ODONTOSTOMATOLOGICHE
English
Class III malocclusion
Delaire face mask
FEM analysis
Maxillary protraction
Computer-Aided Design
Dental Stress Analysis
Elastic Modulus
Humans
Imaging, Three-Dimensional
Malocclusion, Angle Class III
Maxilla
Software
Tensile Strength
Treatment Outcome
Equipment Design
Extraoral Traction Appliances
Finite Element Analysis
Gazzani, F., Pavoni, C., Giancotti, A., Cozza, P., Lione, R. (2018). Facemask performance during maxillary protraction: a finite element analysis (FEA) evaluation of load and stress distribution on Delaire facemask. PROGRESS IN ORTHODONTICS, 19(1), 21 [10.1186/s40510-018-0217-1].
Gazzani, F; Pavoni, C; Giancotti, A; Cozza, P; Lione, R
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/258581
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