Estimation of the Strains in Midpalatal Suture: Computational Biomechanical Study
THAYANE CINARA SOUZA1; João Victor Pinheiro Pedrosa1; Leandro Silva Marques1; Larissa Carvalho Trojan Serpe2; Estevam Barbosa de Las Casas2; Libardo Andrés González Torres1
1 UFVJM; 2 UFMG
doi:10.20906/CPS/COB-2015-1267
Resumo
Rapid Maxillary Expansion (RME) is a technique very frequently indicated, for the correction of transversal problems in the maxillary arch. During the active phase of this treatment the median palatine suture (MPS) is broken and then it is ossified until restitute its original structure. It is reported that the magnitude and frequency of mechanical forces influence the shape and composition of cranial sutures. The most important cyclical force acting on the skull and jaw is the force generated during mastication of food. Thus, the objective of this study is to estimate computationally the deformation in the MPS, during mastication, after the active phase of RME, and correlate them to the mechanobiological cell differentiation theories. The three-dimensional geometry used in the model was extracted from computerized tomography of a 12 year old patient. This geometry was used to construct a finite element model to estimate strains in the MPS. All tissues were considered linear elastic materials with mechanical properties reported in literature. Considering the chewing forces for children who have 6-12 years found in the literature, a force of 35 newtons was applied to the second pr- molar and first molar of the higher hemiarch, in the direction of the long axis of each tooth. After computations, it was obtained that in the outer region, in contact with the jawbone, the SPM showed greater strains, with magnitudes between 0.3% and 7.3%, values close to those needed to stimulate bone synthesis. In the most inner region of the suture, strains were lower, close to 0.1%, only the edges there was strains exceeding 0.5%, values close to those needed to generate cellular resorption. That indicate that the mechanical strains are more favorable for the synthesis of bone close to the previously existent surfaces of bone, and they are the locations where bone could initially appear, as is observed in experimental studies.
Palavras-chave: Biomechanical Model; Rapid Maxillary Expansion; Mechanobiology