抄録
The middle ear function has been studied periodically monitored by means of an impedance meter in four elementary school classes, approximately 157 children, over a period of two years.
The children (16.7%) showing pathological tympanograms in the first year significantly decreased from the last semester of the second year, and the cases of secretory otitis media also decreased from the beginning of the third year. It is thought that these two phenomena were caused by the effects of treatment and of aging. Furthermore, from the clinical observations, it seems that secretory otitis media might be due to upper respiratory tract infection.
