ANATOMIC RELATIONSHIPS BETWEEN OSTMANNS FATTY TISSUE AND EUSTACHIAN-TUBE

To examine anatomic relationships between Ostmann's fatty tissue (OF) and the eustachian tube (ET), we evaluated serial histologic sections of 32 normal temporal bone-ET specimens and made a quantitative analysis of several measurements (height, width, and volume). We compared results in specimens from individuals in whom the ET was still developing (those 19 years and younger) to results in specimens from individuals with adult ETs (those older than 19). We found that 1) the main body of OF is located at the inferolateral aspect of the ET and 2) postnatally, OF grows in volume, mainly by an increase in height, so that OF maintains the same vertical relationship to the growing ET and does not increase in width. The former finding indicates that OF might exert static pressure on the ET not to open widely. The latter finding indicates that the relatively thicker mass of OF may narrow the ET in those with immature ETs. These results indicate a possible role for OF in ET function, which in turn has been implicated in otitis media with effusion.