It's important for dentists to know what you put in your mouth when they're trying to fix your teeth. Lollipops, coffee, booze, cigarettes -- all of these things can damage your teeth, but your dentist can't give you accurate advice if you tell fibs about your habits.
A new sensor, though, could let your dentist know what you're doing without you having to own up to it. Created by a team of researchers at National Taiwan University's Department of Science and Information Engineering and Department of Electrical Engineering, it fits in your mouth and can tell the difference between eating, drinking, speaking, and coughing, with 93.8 percent accuracy.
At less than half an inch in size, the sensor can be embedded in an artificial tooth, or fitted into dentures or braces. It uses a small accelerometer to monitor the movements of the mouth. Oral activities such as coughing, chewing, drinking, and speaking create a different teeth motion, the researchers said. The sensor records and identifies motion profiles for each activity, building classifiers to distinguish between them.
This information can then be conveyed to the dentist. At this point, the team is still using a wired connection to both retrieve data and power the sensor; in time, the researchers hope to be able to add a tiny battery for power, and a Bluetooth receiver to transmit the data wirelessly to a nearby smartphone.
So far, the system's been tested on eight human subjects, each of whom submitted 15 activity samples for coughing, drinking, chewing, and speaking -- 60 samples total per subject. This provided enough information to create a motion profile for each subject. Because everyone moves differently, the device, if brought into use, will probably require some sort of calibration for each individual.
The device is too big to be fitted to an existing tooth, so an artificial tooth coated with dental resin for safety is the best way to install it, possibly replacing an existing tooth. These artificial teeth will need to be removed for cleaning each day; the researchers propose an overnight docking and charging station to be used to keep the sensor functional.
Combined with the graphene "tooth tattoo" that monitors tooth bacteria, it could pave the way to much happier, healthier mouths. But only if it gets a bit smaller -- at its current size, we imagine wearing it would feel like having a piece of popcorn stuck between your teeth. Ouch.
The results of the study have been published as "Sensor-Embedded Teeth for Oral Activity Recognition" (PDF).