[The clinical value of wideband tympanometry in the diagnosis of otitis media with effusion].

Objective:To establish normative data for wideband absorbance measurements in Chinese with normal ear and effusion ear using wideband tympanometry(WBT) and determine the WBT curves of normal ears and effusion ears to facilitate the use of it. To investigate whether there are difference between the WBT absorbance in children aged 2-16 and adults above 16. To compare the sensitivity and specificity of WBT and conventional tympanometry tests for diagnosing otitis media with effusion (OME).Method:One hundred and seventy-six patients(342ears) ,from January 2015 to December 2015, were enrolled, including 96 males and 80 females whose ages ranged from 2 to 74 years. All of these patients, who underwent physical examination, ear endoscopy, conventional tympanometry and pure tone audiometry, were divided into three groups, namely normal, negative pressure and effusion according to the clinical diagnosis. WBT was carried out in these patients to analyze whether there are difference in the absorbance between children and adults in normal ears.The absorbance diagram of normal, effusion and negative pressure ears were mapped in Chinese population.The normal WBT curve was named as type N (normal) curve, the middle ear effusion curve as type E (effusion) curve, and the middle ear negative pressure curve as type P (negative pressure) curve. Pairwise comparison was carried out to analyze the difference of the WBT absorbance among these WBT curves. Other 40 patients (66 ears) with clinical diagnosis of middle ear effusion, including 22 males and 18 females with ages ranged from 3 to 36 years old, underwent exploratory tympanotomy. These 40 cases were detected preoperatively by both conventional tympanometry and WBT by which the sensitivity and specificity were compared in the diagnosis of middle ear effusion.Result:The normative data of WBT absorbance in Chinese with normal ear over 2 years old was established. The WBT absorbance at all frequencies between children and subject over 16 years old showed no statistically significant difference except for 10 frequencies in all 31 frequencies detected. The variations in the absorbance were mainly concentrated on the frequencies ranged from 500- 2000 Hz,in patients with OME. In the frequency range of 500-2000 Hz, the absorbance amplitudes in type N curv >type P curve>type E curve. There were significant differences in WBT absorbance at all frequencies between type N and type E between within 500-2000 Hz.The sensitivity and specificity of WBT for middle ear effusion were 94.8% and 87.5%, respectively, which were higher than that of conventional tympanometry with 91.3% of the sensitivity and 62.5% of the specificity.Conclusion:The WBT absorbance is consistent at most of the frequencies in Chinese. The normal ear, effusion and negative pressure in the middle ear can be distinguished by WBT curve. WBT can be useful for clinical diagnosis of OME, which has a higher sensitivity and specificity than conventional tympanometry.