Myringosclerosis and Otosclerosis – Their Effects in the Stapes Footplate

The ear connects people to the outside world and contributes to sense of balance. However, a number of disorders can interrupt this perfect state, resulting in hearing impairment. Middle ear pathology, like myringosclerosis or otosclerosis is frequently seen and its early treatment is crucial to prevent others worst situations. The myringosclerosis is a formation of dense connective tissue in the eardrum, not usually associated with hearing loss. Otosclerosis is an abnormal growth of bone near the stapes and can result in conductive and/or sensorineural hearing loss [4]. In this work, a 3D solid model of tympano ossicular chain was built [2] with the integration of an improved membrane model [1], based on the finite element method, using the ABAQUS software. The ossicles (malleus, incus and stapes) were considered isotropic and the eardrum orthotropic. The material properties were obtained by literature [5]. The ligaments that connect the ossicles to the cavity tympanic walls have a hyperelastic behavior being a Yeoh model applied. The strain-energy function, for the Yeoh model can be written as [3]