Function and dysfunction of the eustachian tube in children.

Various tests of the Eustachian tube function was studied with the impedance technique in a pressure chamber. The material consisted of otologically healthy children and adults and of children with positive histories of otitis media. The active pressure equilibration capacity, i.e. the muscular opening function of the tube was poorer in the children (3-12 years) than in the adults and poorer in the children with than without otologic histories. The muscular opening function improved with age, as confirmed by repeated tests during 3 years. The middle ear pressures by tympanometry were lower in the children than in the adults and 1/5 of the otologically healthy children had underpressures equal to or exceeding -1kPa. It is suggested that the lower limit of normal middle ear pressure by tympanometry in children should be - 2kPa. The passive pressure opening and closing functions of the tube, which reflect its closing forces or its protective function, did not, however, differ between the adults or the children. The results imply that there is a primary muscular opening hypofunction of the tube in children which may be an underlying etiologic factor in the development of otitis media.