Development of the facial recess: implications for cochlear implantation.

More attention is being focused on the growth and development of the facial recess because of the use of cochlear implantation in children over 2 years of age and the prospect of using implants in even younger children. The facial recess and the extended facial recess were measured in 123 temporal bones from 73 individuals ranging in age from 8 weeks in utero to 7 years after birth. The goals were to trace the development of the facial recess and to determine whether this area continues to grow into childhood. The facial recess enlarges throughout fetal life with the development of the facial canal and the tympanic annulus. Reichert's cartilage, seen early in utero in the facial recess, gradually resorbs but may persist in the newborn. In full-term infants, the facial recess reaches 3.25 mm at the oval window and 2.62 mm at the round window. The extended facial recess reaches 3.79 mm at the oval window and 3.04 mm at the round window. No statistically significant growth of the facial recess after birth could be demonstrated in this study. The data suggest that the facial recess is probably adult sized at birth and should allow surgical access for cochlear implantation in very young children.