This unique mouth exercise can banish double chins and give you a supermodel-worthy jawline in seconds. But should we all be doing it? We explore the weird and wonderful world of mewing.

Mewing is the latest beauty trend that TikTok has gone crazy for. This unconventional mouth exercise that changes the shape of your face and jawline without any surgical assistance has been rumoured to be how supermodel Bella Hadid gets her ‘snatched’ jawline when posing for pictures.

So it probably won’t surprise you that #mewing has had nearly 2 billion views on TikTok. Yep, 2 billion. Of course, if there’s a trend to be had, then TikTok is having it - this is where we discovered how to use fruit as makeup and exactly what is an internal shower (spoiler alert: it involves chia seeds and a glass of water). And the videos of people mewing are quite astounding - take a look at Danish beauty TikTokker, Caroline Hannibal demonstrate the technique.

But of course, it didn’t start on social media. Mewing was created by British orthodontists Dr John Mew and his son Dr Mike Mew. Dr John Mew, who posts videos to his Orthotropic YouTube channel and whose video ‘Doing Mewing’ has amassed over 1.8 million views, says it involves keeping the tongue on the roof of the mouth while your mouth is closed pushing your tongue upwards into the palette and pressing your molar teeth together. Having the correct tongue, jaw and neck posture can help improve jaw problems, mouth muscle pains, and sleep apnea - a disorder characterised by pauses in breathing or periods of shallow breathing during sleep, it's claimed. Dr Mew also suggests that not chewing our food enough and breathing through our mouths more due to the explosion of allergies has made our jaw muscles lazy. And whilst Dr Mew admits that he created the technique for a number of health reasons, many are using the technique to tighten their jawline.

Does mewing actually work?

Dr Sarah Tonks , cosmetic physician, maxillo-facial (jaw muscle) surgeon, dentist and founder of The Lovely Clinic , said that while the Mewing technique could be sufficient to move the jaw, there is no scientific evidence or research backing the technique. "This has been around for a long time and the author was ejected from the British Orthodontic Society," she told GTG. "I doubt that the pressure given by tongue position would be sufficient to move bone although it's true that, for example, you could make the masseter muscle larger which would make the face wider. At the moment, Mewing is not accepted by any orthodontic body. But that's not to say that with further study at some point in the future it may be."

According to cosmetic dentist  Dr Uchenna Okoye , Clinical Director of London Smiling, the Mewing technique won't do any harm but she is sceptical. "There is no research to show that it [mewing] works unless it is with a growing jaw. We know certain movements - such as when a child sucks their thumb - make the jaw narrow. Mewing can be used to expand the jaw which means you can breathe better, but there is no literature anywhere that shows that this technique works for adults." It's no substitute for orthodontic treatment, however. "Mewing on its own won't work - maybe with a child - but they won't remember to sit down and do these exercises every day."

How do you do mewing?

It takes a bit of practice but once you’ve got it, mewing is easy to do. “The technique is to keep the tongue pressed against the roof of your mouth, lips closed, touching the teeth gently and breathing through your nose,” explains aesthetic doctor and founder of skin clinic The Luxe, Dr Usman Qureshi.

Can mewing do damage?

On this point, the advice is fairly universal. “This isn’t something I would recommend for permanent results as it’s unrealistic that someone could hold this 'pose' all day every day,” says Qureshi “And if they do it could cause adverse effects such as crooked teeth, chipped teeth and even cause pain in the jaw/TMJ pain. If you are looking for safer more permanent results I would recommend visiting a reputable cosmetic doctor to review your facial profile and give a personalised consultation.”

And cosmetic dentist and advanced facial aesthetician, Dr Tara Francis agrees: “Mewing requires you to keep your teeth touching at times that are unnatural, which can potentially wear it down and maybe even cause cracks in the enamel. Unless you’re a clencher or grinder, upper and lower teeth only touch when swallowing and don’t even always touch when chewing as food will be between them. If overdone, the unnatural position of the tongue and jaw posture could also cause aches in the mouth, jawline and neck. Misalignment of the teeth is also a risk.”

So if it’s a defined jawline for a quick picture you’re after, then do as Bella Hadid (supposedly) does and get going with your finest mewing. As for the rest of the time? Just leave your tongue and your teeth where they’re meant to be.