Tympanometry and acoustic reflectometry in ears with chronic retraction without effusion

Objective: Purpose of this study was to find out test accuracy and predictivity of tympanometry (TYMP) and parameters (reflectivity and curve angle) of acoustic reflectometry (AR) in the ears with prior clinic and otoscopic evidences of effusion in which no effusion was detected by myringotomy, by comparing with the data found in normal ears and in those with effusion. Methods: While study group included 31 ears with chronic retraction in which no effusion was detected by myringotomy, control group included 150 fully normal ears and 150 ears with effusion confirmed by myringotomy. B tracings in TYMP, and values of reflectivity higher than 5 and curve angle lower than 75° in AR were accepted as indicators of effusion; in the combined test, the ears with non-B tracings in which curve angle higher than 75° were accepted as those without effusion. Results: False positivity values of TYMP, reflectivity and curve angle and the combined test found in the ears with chronic retraction without effusion (29, 23, 19 and 35% respectively; χ 2-test, P>0.1) were significantly higher than normal ears ( χ 2-test, P