Researchers trial magnetic ‘lockjaw’ against obesity

New Zealand researchers have created a weight-loss device that uses magnets to clamp a patient's jaw together -- hailing it as a new tool against obesity despite critics likening it to an instrument of medieval torture. 

The "world-first" innovation involves a dentist fitting magnets and locking bolts to the patient's upper and lower molars, allowing the jaws to open only two millimetres.

Lead researcher Paul Brunton, from the University of Otago's school of health sciences, said this restricted the user to a liquid diet without limiting breathing or speech.

"It is a non-invasive, reversible, economical and attractive alternative to surgical procedures," he said.

"The fact, there are no adverse consequences with this device."

In a paper published in the British Dental journal this month, they said seven women each lost an average of 6.36 kilograms (1.0 stone) during a two-week trial with the device, called the DentalSlim Diet Control.

It found the patients experienced some initial discomfort but generally found the device "tolerable".

The invention generated a strong response on social media, with many users accusing the researchers of shaming fat people and questioning the ethics of the trial.

One critic called it "repulsive and dehumanising" while another said it risked entrenching unhealthy eating habits.