I don't immediately see a picture of the actual chip to get a reference size bybitself, that that chip inside the tooth is pretty wild. I wonder how you would even begin to power electronics within such a space. Or perhaps this is more of a marketing level of graphics.
The second link isn't exactly forthcoming on the battery technology used, but at least says:
> and its power consumption is low enough that the device can last from six months to a year on a battery of the equivalent size
The average "width" of the first mandibular molar from this article[1] is 5.1-5.2mm. It sure would be interesting to see a CAD model of the design inside the module on the band. The graphics from the posted article vs. the first link above are also a bit different, making it even harder to infer much I think.
