الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 99 |  |  |
| | | from | 99 | | |
Abstract
The popularity of cochlear implantation and with the advent of new electrode designs and greater emphasis on preservation of residual hearing, there has been renewed interest in use of round window as a portal for electrode insertion. That renewal interest of the RW approaches necessitates further acquaintance of its complex anatomy and its variations. Histological and radiological techniques have been used to measure the RW dimensions. The histological sections show the anatomy in great detail but, because of its two-dimensional nature, the spatial relationship between anatomical structures is not demonstrated.
The round window is one of the two openings from the middle ear into the inner ear. It is sealed by the round window membrane. The RWM is located in the deeper part of a conical bony depression called the round window niche. The round window niche is located at the posteroinferior aspect of the medial wall of the tympanic cavity separated from the sinus tympani by a bony bridge, the subiculum. It is closed by the round window membrane. It is limited anterosuperiorly by the promontory and inferiorly by the hypotympanum.
The aim of this work is to study the anatomical characteristics of human RW and the importance of variations in this anatomy to the process of cochlear implantation.