1990 年 21 巻 1 号 p. 83-84
The morphological changes of the fissula ante fenestram in 440 temporal bones of 222 individuals were studied. The fissula was observed in 366 bones (83.2%). The fissula orificed at the site of tympanic cavity in 81 bones, at the site of annular ligament in 78 bones and at the site of vestibule in 350 bones. There were no differences between right and left ears and no influence by aging on frequency and the site of orifice of the fissula. Otosclerotic change was also observed at any sites other than the fissula. And this confirms also the fissula does not always relate the focus of otosclerosis.