Wideband Reflectance Norms for Caucasian and Chinese Young Adults

Superiority of nitinol piston over conventional prostheses in stapes surgery: first comparative results in the Chinese population in Taiwan

BACKGROUND

A growing number of studies conducted on stapes surgery have suggested that firm and adequate attachment of the prosthesis onto the long process of the incus plays a key role in surgical success. For this reason, a new prosthesis made of Nitinol characterized by "self-crimping" has been developed. Although better postoperative outcomes achieved with a Nitinol piston have been previously confirmed, the superiority of the Nitinol piston over the conventional manual-crimping prostheses remains controversial. The aim of this study was to determine the advantages of the Nitinol piston with regard to hearing improvement.

METHODS

We retrospectively compared postoperative hearing in otosclerosis surgeries with the Nitinol piston versus the manual-crimping prostheses. Sixteen surgeries with Nitinol pistons (carried out between April 2007 and August 2009) and 21 surgeries with conventional prostheses (carried out between January 2004 and January 2009) were evaluated. All patients received pure-tone audiograms preoperatively and postoperatively.

RESULTS

In the Nitinol piston group, the air-bone gap (ABG) average (7.92 + or - 6.75 dBHL) was significantly smaller postoperatively than preoperatively (26.79 + or - 8.33 dBHL, p < 0.001). Similarly, the ABG average for the conventional piston group (13.09 + or - 6.99 dBHL) was significantly smaller postoperatively than preoperatively (26.19 + or - 6.76 dBHL, p < 0.001). Although both groups demonstrated an improvement in average ABG postoperatively, the Nitinol piston group showed a greater improvement than the conventional piston group (p = 0.018). Additionally, ABG closure within 10 dB was attained in significantly more patients (75%) in the Nitinol piston group compared with the conventional piston group (33.3%, p = 0.012).

CONCLUSION

The Nitinol piston has a distinct advantage over conventional prostheses, providing an easier, safer and more effective treatment option in otosclerosis surgery. To our knowledge, this is the first comparative analysis of hearing results of the Nitinol piston with conventional prostheses in the Chinese population in Taiwan. In this population, there is a much lower prevalence of otosclerosis, leading to a lack of surgical experience in otosclerosis surgery, even at large medical centers. This may explain, in part, the relative lack of studies conducted on stapes prostheses in Asian patients. Therefore, our preliminary research may provide a reference for future investigations on stapes surgery in Asian patients with otosclerosis based on ethnic differences.

Sound-conduction effects on distortion-product otoacoustic emission screening outcomes in newborn infants: test performance of wideband acoustic transfer functions and 1-kHz tympanometry

OBJECTIVE

Universal newborn hearing screening (UNHS) test outcomes can be influenced by conditions affecting the sound conduction pathway, including ear canal and/or middle ear function. The purpose of this study was to evaluate the test performance of wideband (WB) acoustic transfer functions and 1-kHz tympanometry in terms of their ability to predict the status of the sound conduction pathway for ears that passed or were referred in a UNHS program.

DESIGN

A distortion-product otoacoustic emission (DPOAE) test was used to determine the UNHS status of 455 infant ears (375 passed and 80 referred). WB and 1-kHz tests were performed immediately after the infant's first DPOAE test (day 1). Of the 80 infants referred on day 1, 67 infants were evaluated again after a second UNHS DPOAE test the next day (day 2). WB data were acquired under ambient and tympanometric (pressurized) ear canal conditions. Clinical decision theory analysis was used to assess the test performance of WB and 1-kHz tests in terms of their ability to classify ears that passed or were referred, using DPOAE UNHS test outcomes as the "gold standard." Specifically, performance was assessed using previously published measurement criteria and a maximum-likelihood procedure for 1-kHz tympanometry and WB measurements, respectively.

RESULTS

For measurements from day 1, the highest area under the receiver operating characteristic curve was 0.87 for an ambient WB test predictor. The highest area under the receiver operating characteristic curve among several variables derived from 1-kHz tympanometry was 0.75. In general, ears that passed the DPOAE UNHS test had higher energy absorbance compared with those that were referred, indicating that infants who passed the DPOAE UNHS had a more acoustically efficient conductive pathway.

CONCLUSIONS

Results showed that (1) WB tests had better performance in classifying UNHS DPOAE outcomes than 1-kHz tympanometry; (2) WB tests provide data to suggest that many UNHS referrals are a consequence of transient conditions affecting the sound conduction pathway; (3) WB data reveal changes in sound conduction during the first 2 days of life; and (4) because WB measurements used in the present study are objective and quick it may be feasible to consider implementing such measurements in conjunction with UNHS programs.

Wideband absorbance tympanometry using pressure sweeps: system development and results on adults with normal hearing

A system with potential for middle-ear screening and diagnostic testing was developed for the measurement of wideband energy absorbance (EA) in the ear canal as a function of air pressure, and tested on adults with normal hearing. Using a click stimulus, the EA was measured at 60 frequencies between 0.226 and 8 kHz. Ambient-pressure results were similar to past studies. To perform tympanometry, air pressure in the ear canal was controlled automatically to sweep between -300 and 200 daPa (ascending/descending directions) using sweep speeds of approximately 75, 100, 200, and 400 daPas. Thus, the measurement time for wideband tympanometry ranged from 1.5 to 7 s and was suitable for clinical applications. A bandpass tympanogram, calculated for each ear by frequency averaging EA from 0.38 to 2 kHz, had a single-peak shape; however, its tympanometric peak pressure (TPP) shifted as a function of sweep speed and direction. EA estimated at the TPP was similar across different sweep speeds, but was higher below 2 kHz than EA measured at ambient pressure. Future studies of EA on normal ears of a different age group or on impaired ears may be compared with the adult normal baseline obtained in this study.