Tympanic Membrane Perforations in Children

Abstract

ETIULt~~~T ~~'~D PATHOGEIVESIS hE EARDRUM is composed of three lay-H' E EARDRUM is composed of three layers-an outer epithelial layer, a middle fibrous layer, and an inner mucosal layer. Most persistent perforations are due most commonly to chronic infection, and in these the epithelium has grown over the edges and prevented closure. The edges of such perforations appear white and thickened. Perforations at the drum margin or at the limbus tend to be the most resistant to closure.Perforations of the eardrum are caused by trauma or infection. In children the chief cause is otitis media. Less frequently, trauma to the ear as by a direct blow, blast, concussion, or head injury is the causative mech-.anism. External otitis rarely leads to this complication. Perforations associated with cholesteatoma are usually at the postero-superior periphery of the drum, and ordinarily do not heal spontaneously.The majority of perforations, when not infected or after the infection has subsided, tend to heal spontaneously. Chronic perforations lead to trouble in two ways. Firstly, any ear with a perforated tympanic membrane is susceptible to infection, especially after water gets into the ear. Secondly, hearing may become impaired. Il'~T~IC~TID~~VS FOR SURGERYThe primary indication for surgical repair is a perforation which has persisted for three to six months after all infection has been cleared from the ear. A second factor which recommends repair is a loss of hearing. I hasten to add that a loss of hearing of more than 30 decibels is often due to ossicular discontinuity, and not to the perforation alone. However, a myringoplasty is part of the total rehabilitation of such an ear. A third indication for myringoplasty is recurrent infection whenever water gets into the ear, in order to protect such a middle ear.