Numerical Analysis on Sound Compensation Performance of Round Window Stimulation in Middle Ear Malformation / 医用生物力学

Objective To study the influence of middle ear malformation on the performance of round window stimulation, so as to provide references for optimization of the round window stimulation middle ear implant. Methods The finite element model of human ear including an asymmetrical two-cavity non-helical cochlea was constructed and compared with experimental data to verify reliability of the model. Based on this model, the effects of three kinds of middle ear malformation, i.e., ossicular chain fixation, ossicular chain fusion and ossicular defect on round window stimulation were simulated by changing material properties of the corresponding tissues. Results The middle ear malformation mainly affected the low-frequency performance of round window stimulation. The ossicular chain fixation and the ossicular chain fusion had a deteriorating effect on round window stimulation. The stapes fixation had the greatest effect on the performance of round window stimulation, with the reduction as high as 47.93 dB. Ossicles defects could improve the performance of round window stimulation, with the maximum increment of 6.24 dB. Conclusions The middle ear malformation had an effect on the low frequency performance of round window stimulation. It is necessary to specifically increase output of the actuator when implanting the round window stimulation middle ear implant.

Analysis of clinical characteristic of the middle ear malformation with cholesteatoma / 中华显微外科杂志

Objective To discuss the clinical characteristic of middle ear malformation with cholesteatoma.Methods From September,2011 to November,2016,23 cases of middle ear malformation with cholesteatoma were collected.Their symptoms,ENT examination,temporal bone high resolution computed tomography (HRCT) and intraoperative findings were analyzed.Results All 23 patients had hearing loss.90.0％ patients had ear discharge and tinnitus.86.96％ patients had perforation in pars flaccida of tympanic membrane.95.7％ patients had poor mastoid gasification.73.9％ patients had undeveloped or dysplastic tympanic antrum.100％ patients had destruction of the ossicular chain.56.5％ patients had malformation of the ossicular chain.52.2％ patients had exposed facial nerve.30.4％ patients had hyperplasia of the attic bone.Conclusion The symptoms and physical examinations of middle ear malformation with cholesteatoma are the same as middle ear cholesteatoma.Poor mastoid gasification can usually be detected on temporal bone HRCT.The most common malformation is dysplastic tympanic antrum,followed by malformation of the ossicular chain,exposed facial nerve and hyperplasia of the attic bone.Temporal bone HRCT can indicate the malformation and destruction quite well.