New AirPod feature: detecting bruxism

On October 6th, Apple employees filed a patent application on the diagnosis and monitoring of bruxism (teeth grinding and clenching) using “earbud motion sensors”. This will be a new health tool with their AirPod Pros.

What is bruxism?

Bruxism is the habit of (un)consciously gritting or grinding the teeth especially in situations of stress or during sleep. It is a common condition, affecting up to a third of the general population. Typical signs and symptoms are a grinding noise during sleep, excessive tooth wear, hypersensitive teeth, aching jaw muscles, and certain facial changes (“square jaw“). Bruxism has no single cause but is instead considered a multifactorial disease.

What is Apple up to?

In their patent, Apple proposed to use the motion sensors in their AirPod Pro’s in order to diagnose and monitor the bruxism behavior of the user.

We already knew that Apple planned to equip it’s Airpod Pro’s with updated motion sensors, and they would focus on fitness tracking. (The current last model – just launched – does not mention fitness capabilities).

The AirPods are well located to capture teeth grinding events. The sound vibrations produced by clenching teeth can easily reach the inner ear through the bones of the skull. They are then captured by the accelerometer in the AirPods.

Vibrations caused by the clenching teeth (below right) travel to the inner ear (middle right) and are picked up by the AirPods (middle left). Copied from the USPTO application.

The captured information is then processed with specific tools like simple high pass filters andnot-so-simple supervised learning methods (SVM, support vector machines).

The data processing at play.

Why is this important?

Bruxism is a multifactorial condition with no easy solution (here a list of possible remedies). One of the more promising tools are “biofeedback devices” in combination with other techniques. These monitor bruxism behavior and inform the user when it occurs, eg. using vibrations or notifications on your smartphone. It is a form of self-regulation to improve health. These tools detect grinding events on different ways: bite pressure, muscle activity, or even the shape of the ear canal. Apple uses a simple approach, and “listens” to the grinding events.

Btw, did you think “dental guards” or occlusal splints are the best solution? Think again. As the name suggests, they “guard your teeth”, but do not necessary take away the grinding and clenching.

Curious

In any case, we are curious what they are working on. Their technique is based only on vibration measurements and probably quite basic. They checked whether it can differentiate between other simple sounds (eg. talking, eating) but did not research if other frequent sounds like snoring could mess up their analysis.

We are pleased that a major party like Apple is paying attention to the issue of teeth grinding. Biofeedback in combination with other techniques can be a big help in reducing bruxism. And Apple wouldn’t be Apple if they turned it into something innovative.

What do you think?


Comments

2 responses to “New AirPod feature: detecting bruxism”

  1. Are you supposed to wear it all night?
    Would battery even last for 7-8 hours of sleep?
    And how comfy is it ti sleep with the AirPods on? wouldn’t they fall?
    And would it just detect it? Or also help improve (which I have no idea how they could do it).

    Cause people already know (probably already dentists and family confirmed) if they have bruxism. So just detecting it might not be such a big deal. It’s like stating the obvious. Can it do something more than detect it?

    1. sitebeheer Avatar
      sitebeheer

      Good questions.

      On the use of Airpods at night: I found this:
      While sleeping with your Airpods Pro in your ears once or twice is safe, doing it every night has a variety of risks. You could swallow or choke on them, get earwax buildup, develop an ear infection, experience hearing loss, damage your Airpods Pro, experience necrosis, or develop sleep deprivation.

      On the time of use: as AirPods are not worn while sleeping, I assumed the bruxism detection to work while awake. This also fits with the biofeedback principle: Apple will warn you when you are grinding your teeth, this does not make sense while sleeping.

      On detection vs improving? This is precisely the feature Apple proposes, the “biofeedback”. Apple will warn you about your grinding habits, and this in itself will (in certain situations) reduce your grinding behaviour. We actually get a lot of related questions about this, I plan a blog post on how it works in detail.

      On knowing if you have bruxism: see our frequently asked questions.

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