Development of an Optimal Relief Method for the Palatal Plate by Stress Analysis

Background: A maxillary-palate-shaped device for simultaneous measurement of bite force and palatal mucosal subsidence at the time of pain onset in dentate persons has been developed. However, palatal mucosal stress analysis in a simulation based on three-dimensional finite element analysis is effective for objective and efficient evaluation of various types of denture-supporting mucosa. Recently plate dentures are not easily modified after the completion of these dentures , so it is essential to effectively assess the sites and magnitude of relief at the time of preparation. However, there is considerable variation in the magnitude of optimal relief and relief range, and there are no guidelines that present these clearly, leading the surgeon to decide subjectively. Thus, this study aimed to develop an optimal relief method to improve the stress bearing capacity of the palatal mucosa. Objectives: The objective of this study, the borderline was set in steps. The changes in stress distribution in the palatal mucosa due to the selective relief of stresses above the borderline were evaluated using a three-dimensional finite element simulation. The purpose of this study was to develop an optimal relief method to improve the bearing capacity of the palatal mucosa. Methods: : The objective of this study, the borderline, was set in steps. A three-dimensional finite element model for the pseudopalatal plate was prepared and used to evaluate the changes in stress distribution in the palatal mucosa due to the selective relief of stresses above the borderline. The resulting data were used to develop the optimal relief method. Results: In the relief model with a borderline of 0.04 MPa or higher, the distribution volume at which high stress of 0.20 MPa or higher is generated was approximately about 800%％ of that with the no-relief model, and in the relief model with a borderline of 0.06 MPa or higher, the respective ratio was approximately about 280％%. On the other hand, the relief models with borderline of 0.14 MPa or higher were about 60%. In the mid-palatal relief model, the distribution volume at which stress of 0.20 MPa or higher was generated was 180% of that in the relief model. Conclusions: The supportive strength of plates can be increased by selectively applying optimal relief rather than standard relief, allowing for easier and more effective plate-denture treatment.