The purpose of this study was to gain anatomical informations of eustachian tube and its accesory structures, such as the internal carotid canal, the tensor tympanic muscle and the middle cranial fossa in human temporal bones. For this study, using serial sections of normal temporal bones from 9 adults, each anatomical relations among those structures was observed at three different sections showing the orifice of the tympanum, the bony portion of the tube and the isthmus of the tube. In each case, individual variations were seen apparently in anatomical relations of the euctachian tube and its accesory structures.
