RESUMO
OBJECTIVE To study the effect of partial ossicular replacement prothesis (PORP) on the middle ear transfer function.METHODS On a incus removed finite element model,a titanium columnar structure which link the malleus and the stapes was used to simulate the function of PORP to transmit acoustic pressure.The effect of placement of PORP on different positions of the manubrium,as well as the insertion of the cartilage between the artificial bone and the fascia on the middle ear transfer function were calculated.RESULTS When the PORP is placed on the neck of manubrium,mid-manubrium and headof malleus removed,the vibration amplitude of the umbo ofthe tympanic membrane is reduced in 200-8000 Hz,and thereduction range in 200-3200 Hz is more than that of 3200-8000 Hz.While the vibration amplitude of the stapes in the200-8000 Hz amplitude increased.The vibration amplitude is basically the same when placed on the neck of manubrium and mid-manubrium,while it slightly increased about 2-3 dB than the former two when the head of malleus removed.In 1000-8000 Hz.When putting the cartilage between the PORP and transplanted fascia,the vibration amplitude of the stapes footplate was slightly increased,but there was a slight difference with different cartilages.CONCLUSION The placement and material property of PORP play an important role in the middle ear transfer function.