Researchers develop an intraoral device for weight loss University of Otago, New Zealand, and UK researchers have developed a world-first weight-loss device to help fight the global obesity epidemic. DentalSlim Diet Control is an intra-oral device fitted by a dental professional to the upper and lower back teeth. It uses magnetic devices with unique custom-manufactured locking bolts. It allows the wearer to open their mouths only about 2mm, restricting them to a liquid diet, but it allows free speech and doesn't restrict breathing. Participants in a Dunedin-based trial lost an average of 6.36kg in two weeks and were motivated to continue with their weight loss journey.