[Magnetic coupling of partially implantable bone conduction hearing aids without open implants].

Introduction: Patients with air-bone-gaps that cannot be corrected successfully by tympanoplasty or with mixed hearing loss may be treated with bone conducting hearing aids. Their disadvantages are the obvious external fixation components or the biological and psychosocial problems of open implants.
Patients and Methods: The principle of these new bone conducting hearing aids is the magnetic coupling between implanted and external magnets. Twin-magnets are implanted into shallow bone beds in a one step procedure. The skin above the magnets is thinned out to a thickness of 4-5 mm, which reduces the attenuation to less than 10 dB compared to direct bone stimulation.
Results and Discussion: The holding strength of the external components is equivalent to partially implantable hearing aids and Cochlea implants and the hearing improvement is similar to other bone conducting hearing aids. We have found the comfort and safety of this system is significantly improved compared to conventional or percutaneous bone conducting hearing aids.
(Georg Thieme Verlag KG Stuttgart, New York.)