What mewing is, what the British Orthodontic Society says about it, what a randomised trial of gum chewing found, and what does change how a jawline looks in photos.
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Short answer
Mewing (pressing the tongue to the roof of the mouth to reshape the face) has no scientific evidence behind it. In 2025 the British Orthodontic Society restated that there is no evidence people can change the shape of their face by holding the teeth and tongue in a position or by facial movements. A randomised trial of daily gum chewing found no change in jaw muscle or jaw shape. Skip it, and skip jaw trainers and "bonesmashing".
What mewing claims
The idea: rest the whole tongue against the roof of the mouth, teeth lightly together, for hours a day, and over time the upper jaw widens and the jawline sharpens. Videos show "before and after" photos, usually with different angles, light, body weight or age.
What the evidence says
What
Grade
What the evidence says
Mewing
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The British Orthodontic Society (2025): no scientific evidence that holding the teeth and tongue in a position, or facial movements, change the shape of the face.British Orthodontic Society, BOS statements
Gum chewing, jaw trainers
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A randomised trial of 58 adults chewing gum three times a day for six months: bite force went up, but jaw muscle thickness and jaw shape did not change.Jung HJ, 2024
Face yoga
Limited evidence
One small pilot without a control group reported changes in middle-aged women. Optional at best; not a way to change bone.Alam M, 2018
"Bonesmashing"
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Hitting your face to "remodel" bone risks fractures and nerve injury. Don’t.
Why do mewing photos look convincing? A chin pushed forward, a head tilted down, the tongue pressed up while the photo is taken, and a camera moved further away all change how a jaw looks in that one photo. None changes the bone.
What does change how a jaw looks in photos
A camera at eye level, from arm’s length or further (close lenses distort the face), with the head level.
Facial hair shaped to the jaw (see the beard guide).
Upright posture: the neck and chin line read cleaner when you aren’t slumped toward the camera.
If your bite, breathing or jaw joint bothers you, see a dentist or orthodontist. That is a health question, not a looks one.
How the app handles this
The app’s plan never includes mewing, jaw trainers or face exercises for bone structure; ordinary chewing gum appears only as an optional, low-evidence extra beside the plan, with its risks. The potential estimate counts only the steps your plan actually holds (skin care, sleep, hair, brows, facial hair, fitness and the like), and it is capped. The measured proportions rest on bone, and the plan doesn’t pretend to move them.
Questions people ask
Does mewing work?+
There is no scientific evidence that it changes the shape of the face. The British Orthodontic Society said so again in 2025.
Does chewing gum give you a jawline?+
A randomised trial of six months of daily gum chewing found no change in jaw muscle thickness or jaw shape.
Can mewing fix my bite or breathing?+
No evidence says it can. Bite, breathing and jaw-joint problems are for a dentist, orthodontist or doctor.