Dimensions of the extended facial recess.

The variability of the dimensions of the facial recess and extended facial recess with age, sex, and degree of pneumatization was measured in 87 temporal bones serially sectioned in the horizontal plane. Although some statistically significant differences in dimensions were identified, the absolute differences were small compared to the range of measurements. The mean dimensions were very similar in all groups studied. The clinical relevance of the data to mastoid surgery and cochlear implantation is discussed.