Mastoid emissary in man. An anatomical-clinical study.

The purpose of the study was establishing differences in the situation of the external orifice of the emissary, its size and angle at which it leaves the skull. It is necessary for optimizaing of position for the internal coil of the speech processor of cochlear implant. As yet, the variability of external foramen of this emissary have not been sufficiently studied, especially in the clinical aspect with respect to the use of cochlear implants. The authors examined 200 skulls of adults of both sexes. The statistically significant differences were observed between sexes and between sides of the body, and they showed a definite regularity. The variability of the site of the emissary is presented in a form useful for clinical purposes.