Non-implantable bone conduction device for hearing loss: a systematic review

There are different treatment options that employ a bone conduction transmission of the sound, for different types of hearing loss, as well as hearing aids, medical intervention via prostheses and surgically implanted medical devices. A middle ear disease causes a decline in the conductive mechanism of hearing. The current possibilities of compensating Conductive Hearing Loss (CHL) solutions include both surgical and no surgical Bone Conduction Devices (BCDs). Due to the invasiveness of the implantable devices and their specific requirements in terms of the temporal bone anatomy, non-implantable BCDs are in some cases preferred in the clinical routine. The goal of this review is to investigate the beneficial effects and safety of non-implantable BC devices, analysing the different type of solutions found so far. A systematic review was performed to identify all the clinical studies evaluating the use of non-invasive BCDs. A qualitative analysis based on data extracted was conducted. From 37 articles, 11 prospective studies and 1 retrospective study were selected for a full analysis, for a total of 173 patients from 4- to 77-years-old. Eight of these studies included adult patients, while the other four are paediatric studies. All the studies analyse non-implantable BCDs commonly used in case of CHL, sensorineural HL and single side deafness. Three of them analyse an adhesive device, six compare the adhesive device with a sound processor mounted on a support fitted on the head, one compare it also with an implant, one analyse the sound processor mounted on different type of support, and one compare different type of sound processor. All the studies showed advantages from the use of non-invasive BCDs, both on adults and children. The non-invasive BCDs analysed in this review show good results both from the audiological and subjective point of view and could be considered a safe and effective solution for patients suffering from conductive hearing loss, sensorineural hearing loss or single-side deafness. More studies are required to confirm these promising results.