Biomechanical Characteristics of the Ossicular Prostheses Model Using the Finite Element Method / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Extrusion of the ossicular prosthesis into the eardrum has been a persisting a problem accompanying ossiculoplasty. There are several factors concerning extrusion of the prosthesis, for instance, eardrum retraction, infection and the figure of the prosthesis, etc. Recently, many studies have been performed to evaluate the cause of extrusion; however, there have not been any attempts to analyze the extrusion cause from the viewpoint of biomechanics. The purpose of this study is to calculate the stress and strain of the eardrum and the prosthesis and to find the ideal model that prevents extrusion. MATERIALS AND METHOD: Three kinds of the imaginary total ossicular replacement prosthesis (TORP) were designed and biomechanically analyzed using the 3 dimensional finite element method. Equivalent stress and strains were measured and compared between the each group. The distribution of equivalent stress and strain on the eardrum and TORP were also observed. RESULTS: The concave disc shows the smallest in value of the maximum equivalent stress & the maximum equivalent strain. In all eardrums, the stress was concentrated along the contact area with the disc margin, especially toward the center of the eardrum. In all TORPs, the upper 1/4 of the shaft and margin of the disc toward center of the eardrum was the most stress-concentrated area. CONCLUSION: These results indicate that concave disc could be the most suitable for preventing extrusion.