ABSTRACT
Objective To study the postoperative effects on hearing restoration after different types of ossicular reconstruction with partial ossicular replacement prosthesis (PORP). Methods CT data of the right ear from a healthy volunteer were digitalized and imported into PATRAN software to reconstruct the 3D finite element model of the ear by a self compiling program. Dynamic analysis was conducted on the sound transmission to make comparison between the calculated results and experimental data. Results Results of the dynamic analysis for normal human ear were in good agreement with the experiment data, which confirmed the validity of the FE model. At the frequency between 0.1~10 kHz, hearing restoration with partial retaining the handle of malleus was better than that without retention after the replacement of PORP, and the value of hearing restoration was between 11.56~28.91 dB. The maximum stress of tympanic membrane with partial retaining the handle of malleus was less than that without retaining. At the frequency between 0.1~0.6 kHz as well as between 2~10 kHz, better hearing restoration was obtained when the thickness of the cartilage slice was 2.0 mm. At the frequency between 0.6~2 kHz, better hearing restoration was obtained when the thickness of the cartilage slice was 0.1 mm. Conclusions For ossicular reconstruction with PORP, the effect of retaining the handle of malleus was much better than that without retaining. The effect of hearing restoration was better when the thickness of the cartilage placed between the tympanic membrane and the contact surface of the PORP was within the range of 0.1~2.0 mm.