Investigation of relation with internal acoustic Meatus size and middle ear variation

Internal acoustic meatus is a bone conduit (chanel) which connects the auris interna to the middle cranial fossa. It extends laterally inside the petrosus part of the temporal bone. Important formations such as; facial nerve, vestibulicochleari nerve, labyrinthine artery and labyrinthine vein passes through the internal acoustic meatus. COM,perforation of tympanic membrane, is characterized by hearing loss, ear discharge and lasting more than 3 months and is an inflammatory process of the otitis media with completely unresolved medical treatment. Bone resorption (osteoclasis) of COM with cholesteatoma is more serious than osteoclasis in non cholesteatoma COM. In our study, we have studied 49 patients in Afyon Kocatepe University Hospital of Medicine Faculty, between May 2011 and February 2014 due to chronic otitis media were operated (mastoidectomy) retrospectively operative notes, and if symptoms have detected pathology and variations. Os taken in the axial and coronal plans were examined temporal CT findings. The demographic data of patients undergoing surgery, pre-operative diagnosis was noted. Pre-operative CT with internal acoustic meatus (IAM) of morphometric measurements were made. IAM entry angle, channel length, diameter, and the distance from the entrance of the aquaductus vestibularis sigmoid sinus external ear was measured. At the same time in file scaning we assested the situation of koerner's septum, COM, kolesteatom, tympanic membrane retraction, status of tympanic membrane (STM), ear discharge, dehiscence of the facial nevre (DFN), bone chain status and lateral semicircular canal conditions were evaluated. Compared with LSC dehiscence of the relationship between DFN; A statistically significant difference was found between them. LSC dehiscence with the presence of cholesteatoma, DFN, compared to the relationship between STM; the statistically significant difference was seen among them. IAM morphometry found a statistically significant only between the right and left wide diameter compared to each other. A significant moderately coleration between left IAM chanel lenght and left sigmoid sinus and the distance between the outer ear canal statistically was found. As a result of our study we found that the cholestoma has effect on dehiance of STM, DFN and LSC. In our study, the values to be low compared to other studies, we believe that stem from ethnic and geographical differences.