Prosthetic teeth could make great hearing aids, according to researchers, who have found that vibrations applied to replacements for lost teeth travel well through jawbones to the inner ear.
In their report in the Journal of the Acoustical Society of America, they say the finding could lead to discreet alternatives to conventional hearing aids and cochlear implants often used by people with hearing impairments.
Previous tooth-based hearing aids designs clipped on to molars and received sound wirelessly from a microphone placed behind the ear.
Dental researcher Jianxiang Tao and colleagues want to take the concept a step further, turning tooth implants into hearing aids. The electronics that impart sound vibrations would be built into the portion of a false tooth anchored into the jawbone, says Tao, of Tongji University in Shanghai.
But first, the team had to determine how well dental implants transmit sound compared with natural teeth and the mastoid bone behind the ear, on which other types of hearing aids rely to work. So they applied sound tones to the implants, natural teeth and mastoid bones of 38 people with hearing loss and a single dental implant.
For a wide range of frequencies, the volunteers could hear sounds through implants as well as, or better than, through natural teeth or mastoid bones, the team reports.
Front-tooth implants appeared to work slightly better than dental implants toward the back of the jaw. That may be because jawbone at the front of the mouth is harder than jawbone at the back, the team speculates. Lower teeth and implants worked as well as uppers for transmitting sound.
Compared with traditional hearing aids, dental implant hearing aids could offer “excellent concealment, good comfort and improved quality of sound”, the researchers write.
Study details
The sensitivity of bone conduction for dental implants
Fengxuan Ren, Yutong Li, Lidan Chen, Jiaqi Huang, and Jianxiang Taoa)
Published in The Journal of the Acoustical Society of America on 2 September 2022
Abstract
Dental implants are connected to the alveolar bone by osseointegration. Dental implants could be used as a potential bone conduction (BC) hearing assistive device in the mouth. However, the BC threshold of dental implants has not been reported. The present study aimed to examine the pure tone auditory thresholds of normal human subjects to BC stimulation of the implants. Dental implants showed a significantly lower BC threshold than natural teeth and mastoids. Mandibular dental implants had BC sensitivity similar to that of maxillary dental implants. The BC threshold of anterior dental implants was significantly lower than that of posterior dental implants. Dental implants exhibited excellent BC properties.
Science News article – False teeth could double as hearing aids (Open access)
See more from MedicalBrief archives:
Losing hearing in middle age may increase dementia risk
Best practices for hearing preservation in cochlear implantation
Cochlear implants for adults should be recommended more often