Vol.99 No.2 contentsPRACTICA OTO-RHINO-LARYNGOLOGICA
Vol. 99 No. 2 February 2006
How to Evaluate Mobility of the Auditory Ossicles
during Middle Ear Surgery
Kiyofumi Gyo
(Ehime University)
The outcome of tympanoplasty depends on a variety of factors, such as middle ear disease, tubal function, surgical skill, and the type of ossicular reconstruction. The mobility of the auditory ossicles, especially the stapes, is thought to be one of the most critical factors affecting postoperative hearing. Most otologic surgeons assess ossicular mobility by placing an ear pick on the ossicle and moving it by hand. This maneuver provides only a rough estimate, and the results are subjective. This paper reviews the ossicular vibration testers developed for use during middle ear surgery.
In 1951, Zollner reported an ossicular mobility tester called "Schallsonde", but the device did not become popular because its clinical significance was not fully recognized at that time. In 1997, we developed an ossicular vibration tester utilizing a pair of ceramic elements. Although it provided important information on ossicular mobility, clinical assessment of the device revealed several intrinsic disadvantages. In 2001, Wada et al. introduced a revolutionary measuring system utilizing a single ceramic element and a micro-pressure sensor to evaluate stapes mobility. Recently, we developed a new ossicular mobility tester utilizing an electromagnetic driver and a piezoelectric sensor. The device is computer-controlled and overcomes most of the drawbacks of our previous system. The design, principles, and measuring procedures are reported.
Key words : osssicular fixation,
tympanosclerosis, middle ear impedance