Introduction
In the 1960s, Professor Per-Ingvar Brånemark at Göteborg started his pioneering work on the unique properties of titanium in relation to bone and soft tissue, osseointegration. Following the early development of titanium implants for dental rehabilitation the next step concerned the idea of using a bone-anchored titanium implant requiring skin penetration, with which to attach the hearing aid.
The present paper is the first in a series of presentations implying an inter-disciplinary development program for bone-anchored hearing aids. The study described and examined the mechanical system used to gain osseointegrated entry into the skull. The input impedance into the head in the frequency range of 250 to 8000 Hz, both with and without skin penetration, was measured in 8 patients. The observations were of the utmost significance for further development of bone-anchored hearing aids, which nowadays are such useful tools for the rehabilitation of many hearing disabled individuals.
