Notched incus prosthesis in tympanoplasty - …
2. Smyth GD. Five-year report on partial ossicular replacement prostheses and total ossicular replacement prostheses. Otolaryngol Head Neck Surg 1982; 90(3 Pt 1):343–6.
Ossiculoplasty and Incus Replacement Prosthesis
AB - System miniaturization and steady progress towards a totally implantable prosthetic system is the current trend in cochlear implant technology. To achieve this objective, the external microphone of present implants needs to be implantable. This goal can be accomplished by placing a miniature accelerometer on the ossicular chain in the middle ear to detect and convert bone vibrations into an electrical signal for further processing and stimulating cochlear electrodes. This paper describes the characterization of the umbo of a human temporal bone before and after the removal of the incus to determine the impact of the resulting change in umbo mechanics and attached accelerometer performance. With the removal of the incus, the umbo vibration acceleration frequency response in the direction perpendicular to the tympanic membrane increases by 5 dB below 2 kHz. Above 2 kHz the response diverges due to the change of ossicular chain resonant frequency caused by the removal of the incus. However, at each frequency the umbo vibration acceleration exhibits a linear function of the input sound pressure level (SPL) with a slope of 20 dB per decade before and after removal of the incus, A commercial accelerometer attached to the umbo shows similar characteristics. From the measurement results of umbo characterization, a miniaturized implantable accelerometer with a packaged mass below 20 milligrams, a sensing resolution of 35μg rms/√Hz, and a bandwidth of 10 kHz would be required to detect normal conversation.
This is most readily accomplished by simultaneously advancing and rotating the prosthesis onto the incus as the lenticular process slides along the incus bridge portion of the bucket into the well (counter-clockwise direction in a right ear and clockwise in a left ear).
Ossicular Replacement Prostheses
Ossicular prostheses are commonly placed in patients with ossicular destruction or disruption due to cholesteatoma, chronic otitis media, or congenital ossicular malformation. Autografts were initially used for ossicular chain reconstruction due to their biocompatibility and good sound conduction.
Ossiculoplasty and Stapedioplasty with Titanium Prostheses
Occasionally one may migrate medially through the oval window CASE 1 Malleal & incudal prosthesis TORP = Total Ossicular Replacement Prosthesis PORP = Partial Ossicular Replacement Prosthesis Native stapes Coronal Axial.">
Introduction Ossicles Muscles Ligaments Nerves Walls Spaces Adjacent Final Box STEP 2: MUSCULATURE S TAPEDIUS Dampens Sound Attaches to Head of the Stapes Innervation: CN VII T ENSOR T YMPANI Dampens Sound Attaches to Neck of the Malleus Innervation: V3 Two Muscles: Stapedius + Tensor Tympani
Introduction Ossicles Muscles Ligaments Nerves Walls Spaces Adjacent Final Box AXIAL IMAGING The tensor tympani is a thin elongated muscle that resides superior to the Eustachian tube.