Mewing means resting your tongue flat against the roof of your mouth, with your lips closed and your teeth lightly together, in the hope of reshaping your jaw and face over time. It is one of the most popular ideas in looksmaxxing, and social media is full of before-and-after photos that seem to show it working.
The short answer: there is no good evidence that mewing changes the bones of an adult face. And most of the "results" you see online can be produced in a few seconds with a camera, without any change to the face at all. This guide covers what mewing is, what the research says, the risks orthodontists warn about, and how to take a before-and-after photo that actually means something. If you want to measure your own face the same way every time, our free face symmetry test runs in your browser and nothing is uploaded.
What mewing is
The name comes from John Mew, a British orthodontist who began promoting an approach he called orthotropics in the 1970s, later continued by his son Mike Mew. The idea behind orthotropics is that the way you hold your tongue, lips and jaw guides how the face grows.
Mewing as practised online usually means:
- Tongue on the palate: the whole tongue, including the back of it, rests against the roof of the mouth.
- Lips closed: you breathe through your nose.
- Teeth lightly together: touching, not clenched.
"Hard mewing" means pushing the tongue up forcefully, often for long periods. That version is the one orthodontists worry about most.
What mewing claims to do
The claims go far beyond posture. Promoters say mewing can sharpen the jawline, widen the upper jaw, lift the cheekbones, improve facial symmetry and even change the eye area. Some present it as a free alternative to braces or jaw surgery.
What the research says
In adults
There are no controlled studies showing that mewing changes the shape of an adult jaw. A 2019 article in the Journal of Oral and Maxillofacial Surgery looked at mewing as a social media trend and concluded that it is not supported by scientific evidence as an alternative to jaw surgery.
There is also a physical reason to doubt it. The upper jaw is made of two halves joined by a seam down the middle of the palate. A classic study of people aged 15 to 35 found that this seam gradually fuses over those years, at very different ages in different people. Once it has fused, gentle tongue pressure is not enough to widen it. That is why orthodontists widen an adult upper jaw with surgery or with appliances anchored into the bone, not with posture.
In children
Here the picture is different, and it is the part of the story that is real. While a face is still growing, habits such as mouth breathing and low tongue posture are taken seriously by orthodontists, and specialists may treat them as part of a supervised plan. That is not the same as a teenager pressing their tongue up to get a sharper jaw. If you are still growing and worried about your jaw, breathing or bite, an orthodontist can actually assess it.
The risks orthodontists warn about
In January 2024 the American Association of Orthodontists warned against the trend. It said there is no scientific evidence that mewing reshapes the jawline, and that chronic pressure from mewing can loosen teeth, misalign the bite, contribute to tooth wear and affect speech, sometimes in ways that need treatment to fix.
Most of these risks come from hard mewing: pushing hard, for hours, every day. Ordinary relaxed tongue posture is not the problem.
Why mewing before-and-after photos mislead
This is where most of the "evidence" for mewing comes from, and it is the easiest part to test. A face does not need to change for a photo of it to change. These are the main tricks, most of them unintentional:
Head angle. Tipping the chin down slightly, or holding the phone a little higher, changes how the jaw and neck look in the picture. We tested how much angle alone moves facial measurements with our own tools. On one face photographed from five camera positions, the measured canthal tilt ran from -0.1° to +8.6°: a spread of 8.7 degrees from the same pair of eyes. On another test, the same face measured 0.4% asymmetry facing the camera and 28.5% when turned to one side. Nothing about the face changed between those photos.
Camera distance. A phone held close distorts the face. At about 12 inches, the nose appears roughly 30% wider relative to the face than at five feet. A "before" selfie at arm's length and an "after" photo taken by a friend from further away are not comparable.
Light. Light from above or from one side throws a shadow under the jaw and makes it look sharper. Soft light from the front flattens it.
The mewing pose itself. Pressing the tongue up and holding the head a certain way tightens the area under the chin while you hold it. The photo shows muscles working in that moment, not a change in bone.
Time. Weight changes, haircuts, beards and, for teenagers, normal growth all change how a face looks over months. A before-and-after that spans a year shows all of that at once.
How to take an honest before-and-after
If you want to know whether anything is changing, control everything except the thing you are testing:
- Same distance: at least an arm's length away, ideally further, with the phone on a stand.
- Same height: camera at eye level, straight in front of you.
- Same light: the same window or lamp, at the same time of day.
- Same face: relaxed expression, tongue relaxed, no special pose, in both photos.
- Same hair and beard, or as close as possible.
- Three photos each time, then compare the averages, not the single best picture.
Then measure, rather than eyeballing. Run the before and after photos through the same tools: the face symmetry test, the golden ratio face test and the PSL rating calculator. Small differences of a point or two are normal noise between photos. Our guide to taking an accurate photo of your face covers the setup in more detail.
How our tools measure it
Our tools use MediaPipe FaceMesh, which finds 478 points on your face directly in your browser. Your photo is never uploaded. The symmetry test levels the head before measuring, so a sideways tilt does not change the score, and it warns you when the face is turned too far to measure fairly.
Be clear about what a photo can and cannot show. These tools measure proportions in a photo: distances and angles between points on the face. They cannot see bone directly, and they cannot tell you why a measurement changed. That is exactly why a controlled before-and-after matters: if the photo conditions are the same and the numbers still move consistently, something has changed. If the conditions differ, the numbers mostly tell you about the camera.
What actually changes how a jawline looks
Most of what makes a jawline look defined is soft tissue and presentation, not bone:
- Body composition: fat under the chin and along the jaw has the biggest everyday effect on how sharp the jawline looks.
- Posture in photos: a forward head position softens the line under the chin; standing tall with the head level shows it more clearly.
- Grooming: a beard or hairstyle can strengthen or soften the outline.
- Photo technique: distance, angle and light, as above.
For real structural problems with the jaw, bite or breathing, the options are medical ones: orthodontics, or jaw surgery in severe cases, assessed by a specialist. For the wider picture of what research says about jaws and other features, see our guide to canthal tilt, jawline and midface, and for the eye area, what hunter eyes are.
The bottom line
Good tongue posture is a real idea, and in growing children it is part of real orthodontic care. But there is no evidence that mewing reshapes an adult face, hard mewing carries risks to teeth and bite, and almost every viral before-and-after can be explained by angle, distance, light and pose. If you want to test it for yourself, take controlled photos and measure them the same way each time. Then the numbers can tell you something real.
This article is general information, not medical or dental advice. If you have jaw pain, a change in your bite or trouble breathing through your nose, see a dentist or orthodontist.
Frequently Asked Questions
Does mewing work for adults? There is no good evidence that it does. No controlled study has shown mewing changing the shape of an adult jaw, and the seam in the middle of the palate fuses as people grow up, which is why adult jaw widening needs surgery or bone-anchored appliances.
Can mewing make things worse? Orthodontists warn that it can, mainly hard mewing. The American Association of Orthodontists has said that chronic tongue pressure can loosen teeth, misalign the bite, contribute to tooth wear and affect speech.
How long does mewing take to show results? There is no reliable timeline, because there is no reliable evidence of structural results in adults. Changes that appear in photos within days or weeks almost always come from posture, angle, light or weight.
Is mewing safe for teenagers? A teenager's face is still growing, so tongue posture, breathing and bite are worth getting checked by an orthodontist rather than corrected with online exercises. Hard mewing is not a good idea at any age.
How can I tell if my face has really changed? Take photos under the same conditions each time (distance, height, light, expression), take several, and measure them with the same tools. Our symmetry, golden ratio and PSL tools are free, run in your browser and never store your photo.
References
- Mewing: Social Media's Alternative to Orthognathic Surgery? (2019). Journal of Oral and Maxillofacial Surgery, 77(9), 1743–1744. https://doi.org/10.1016/j.joms.2019.03.024
- American Association of Orthodontists. (2024, January 22). American Association of Orthodontists Warns Against Popular "Mewing" Trend [Press release]. https://aaoinfo.org/wp-content/uploads/2025/01/Risks-of-Mewing.pdf
- Persson, M., & Thilander, B. (1977). Palatal suture closure in man from 15 to 35 years of age. American Journal of Orthodontics, 72(1), 42–52. https://doi.org/10.1016/0002-9416(77)90123-3
- Ward, B., Ward, M., Fried, O., & Paskhover, B. (2018). Nasal Distortion in Short-Distance Photographs: The Selfie Effect. JAMA Facial Plastic Surgery, 20(4), 333–335. https://doi.org/10.1001/jamafacial.2018.0009
- Kartynnik, Y., Ablavatski, A., Grishchenko, I., & Grundmann, M. (2019). Real-time Facial Surface Geometry from Monocular Video on Mobile GPUs. CVPR Workshop on Computer Vision for Augmented and Virtual Reality. https://arxiv.org/abs/1907.06724