Macroscopic bony deficiency of the tegmen tympani in adult temporal bones.

Bony deficiency of the tegmen tympani has been found in cases of fatal intracranial complications following air insufflation of the middle ear. This study set out to discover the incidence and appearance of such deficiencies. Seventy bones were examined and twenty per cent of them had tegmental deficiencies. There was no evidence of erosive disease in any of the bones. Reverse Politzerization following myringotomy has come to be regarded as a potentially dangerous procedure. It is also possible for infection to spread from the middle ear to the meninges, or for C.S.F. to leak into the middle ear from above.