RESUMO
OBJECTIVES: (1) To calculate the sensitivity and specificity of tympanometry with a 226 Hz probe to identify middle ear condition in children; (2) To propose the intersection range of static compliance and tympanometric peak pressure values obtained in ears with and without middle ear effusion. METHODS: 224 children's ears without middle ear alteration, with a mean age of 1 year and 4 months (GI), and 56 children's ears with middle ear effusion (GII), with a mean age of two years, were analyzed. For analysis, the static compliance and tympanometric peak pressure values obtained in the tympanometry with a 226 Hz probe were considered. RESULTS: In the group with no alteration, the Mann Whitney Test showed no significant difference between the sexes for the static compliance (p = 0.085) and tympanometric peak pressure (p = 0.782). No difference was seen, either, for compliance (p = 0.079) and pressure (p = 0.678) values, according to age. When applying the optimal criterion of the ROC curve, the cutoff value obtained was ≤0.26 ml for static compliance (sensitivity= 83.9 %; specificity= 86.6 %) and ≤-56 daPa for peak pressure (sensitivity= 82.1 %; specificity= 84.8 %). When comparing the values obtained for the two groups, it is noted that the data overlap, that is, they create an inconclusive intersection range between the normal middle ear and the altered one. CONCLUSION: The tympanometry cut-off with greater sensitivity and specificity was, respectively, 83.9 and 86.6 % for static compliance and 82.1 and 84.8 % for tympanometric peak pressure. The ranges from 0.16 to 0.43 ml for static compliance and from -109 to 25 daPa for tympanometric peak pressure do not allow defining the presence or absence of alteration in the middle ear, in children aged 6 to 36 months.