We use our mouths to communicate what we want people to know. But what if our teeth started giving away all of our secrets?

That's what could happen with technology being developed by scientists at the National Taiwan University in Taipei. They've developed a new sensor that can be placed into a tooth -- whether through a crown or even a cavity -- and collect data about the person it's implanted in.

Like all kinds of data. Useful information as well as stuff that borders on the creepy, actually.

Built into a tiny circuit board, the sensor uses an accelerometer and "machine learning software" to identify the motions of a person's mouth, such as how much time he or she spends chewing, drinking, speaking, coughing or smoking. The sensor can then collect that information and send the data to a person's smartphone, according to a recent report in the NewScientist.

Translation: this sensor can tell if you've been over-eating or, say, smoking cigarettes against a doctor's orders. Don't go trying to pull one over on your doctor if you have one of these chips implanted in your mouth.

This sensor is still in its early days, as the scientists have tested a prototype on only eight people so far. But it has shown promise in that it correctly recognized oral activities in 94 percent of the cases, they said.

There is one obvious hurdle to overcome, however: the power source. The prototype has been connected via a wire to an external power source, which isn't practical at all.

Oral sensors like this one could have a market if perfected. Ideally, they could assist researchers in diagnosing or treating symptoms like grinding one's teeth, or for monitoring conditions following a surgery.

But they could also get you into deep, deep trouble. You better watch your mouth.

What crazy apps and gadgets have you come across lately? Let us know by emailing us at FarOutTech@entrepreneur.com or by telling us in the comments below.