The eardrums of millions of infants and children throughout the world contain foreign bodies, surgically implanted as prostheses. Myringotomy combined with placement of an indwelling tympanostomy tube (or grommet) has gained widespread acceptance among otolaryngologists as the treatment of choice for persistent middle ear effusion1 and for certain related otologic conditions. But otolaryngologists by no means stand alone: many if not most of the operations currently performed were initially recommended by pediatricians. It is difficult to determine how many such operations are currently performed on pediatric patients in this country, since most operations take place in outpatient settings and therefore escape systematic reportage. A reasonable estimate, however, would be 1 million procedures per year or, because most of them are bilateral, two million tubes inserted. Among the conditions for which the operation is performed, undoubtedly the most common is chronic secretory otitis media. Here there are three interrelated objectives: to remove the effusion, to relieve any associated hearing loss, and to institute and maintain middle ear ventilation. Less commonly the operation may be undertaken for one of various other reasons: to try to reduce the frequency of episodes of acute otitis media2,3; to relieve persistent underaeration of the middle ear when associated with conductive hearing loss or other symptoms2; or to prevent the development of adhesive otitis media or cholesteatoma when atelectasis or, especially, retraction pockets of the eardrum are present.2,4-6 The idea of using an indwelling tube to artificially ventilate the middle ear dates from 1868, when the great Viennese otologist, Politzer, introduced a ventilating eyelet made of hard rubber.7