Temporal bone histopathologic findings in congenital anomalies of the oval window

The histopathologic findings in five temporal bones from three cases showing various stages of oval window development arrest are presented. The anomalies ranged from complete absence of the oval window to congenital cartilaginous fixation of the stapedial footplate. Surgical approaches fro establishment of a new oval window must take into consideration the frequent association of facial nerve anomalies with anomalies of the oval window.