Site for bone-anchored hearing system for children younger than 5 years.

Objective To describe in children younger than the present US FDA-approved 5 years of age the thickest part of the temporal bone available for placement of a bone-anchored hearing system. Children with unilateral hearing loss, as with aural atresia, have deficits in at least language comprehension and oral expression. The early provision of hearing to the atretic ear may minimize the potential for auditory deprivation. Study Design Point prevalence descriptive study. Setting Tertiary referral pediatric hospital. Subjects and Methods Thirty-eight patients less than 6 years old with congenital aural atresia had undergone temporal bone computed tomography (CT). Bone thickness lateral (ie, superficial) to the sinodural angle, in the topmost axial CT slice that included any adjacent petrous ridge, was measured. Results The mean bone thicknesses lateral to the sinodural angles of the atretic ears were 5.1, 5.0, 5.9, 5.2, 5.2, and 4.8 mm for the <1, 1-, 2-, 3-, 4-, 5-year-olds, respectively; of the non-atretic ears, thicknesses were 4.1, 4.9, 5.5, 6.7, 4.3, and 4.7 mm. Conclusion Based on this small case series, bone thickness lateral (ie, superficial) to the sinodural angle is sufficient for many children suffering from aural atresia to have bone-anchored hearing devices implanted younger than age 5 years. Use of the sinodural site would require a magnetic bone-anchored hearing system, which could be repositioned posteriorly at age 5 years when pinna construction and atresiaplasty endeavors typically begin.