Does mewing work? For adults wanting a sharper jawline, there is currently no scientific evidence that it does: the American Association of Orthodontists has stated there is no peer-reviewed evidence that mewing reshapes the jaw, and no randomised trial or cohort study has tested it. That said, the idea behind mewing is not entirely without basis. Resting tongue posture does matter, particularly in growing children, where habits such as mouth breathing and tongue thrust are linked with bite and growth problems. This guide explains what mewing is, what the evidence says, where tongue posture does matter, and what options exist if you are unhappy with your jaw or bite.
Key Takeaways
- Mewing means resting the whole tongue against the roof of the mouth; it became popular online through a movement called "orthotropics".
- There is no peer-reviewed evidence that mewing changes jaw shape in adults.
- Tongue posture and breathing can influence growth in children, where assessment and treatment such as a palatal expander may help.
- Forceful "hard mewing" may cause jaw joint soreness and could push front teeth forward.
- Real skeletal change in adults typically needs orthodontics and sometimes jaw surgery.
What Is Mewing?
Mewing is the practice of holding the entire tongue, including the back third, flat against the palate (the roof of the mouth), with the lips closed and the teeth lightly touching or slightly apart, while breathing through the nose. The name comes from Dr John Mew and his son Dr Mike Mew, UK practitioners associated with orthotropics, an approach that proposes that oral posture guides how the face and jaws grow.
The technique spread widely through social media, often paired with before-and-after photos claiming a more defined jawline, higher cheekbones or a straighter profile. Many of the people trying it are teenagers and young adults who simply want to look and feel better, which is completely understandable. The aim of this article is not to dismiss anyone who has tried it, but to separate what is supported from what is not.
What Does the Evidence Say?
The short answer: mewing has not been properly studied. The American Association of Orthodontists has said there is no peer-reviewed evidence supporting mewing as a way to reshape the jaw. No randomised controlled trial or cohort study has measured whether holding the tongue against the palate changes bone in adults. Online photos are not reliable evidence, because lighting, camera angle, head tilt, weight change and simply clenching the jaw muscles can all change how a jawline looks.
There is also a biological reason to be cautious. The upper jaw is formed from two halves joined along the midpalatal suture, a seam running down the middle of the palate. In children and young teens, this seam is still open, which is why orthodontic expanders can widen the upper jaw. The suture typically fuses by early adulthood. Once it has fused, gentle tongue pressure is very unlikely to separate it, which is why adult arch expansion usually needs surgery or bone-anchored devices.
Mewing Claims vs the Evidence
| Common claim | What the evidence says |
|---|---|
| Mewing gives adults a sharper jawline | No peer-reviewed studies show this. Jawline appearance depends on bone, body fat, muscle and soft tissue. |
| Mewing widens the upper jaw in adults | The midpalatal suture typically fuses by early adulthood, so adult widening usually needs surgical or bone-anchored expansion. |
| Mewing can fix crooked teeth | There is no evidence it straightens teeth. Orthodontic treatment such as braces or clear aligners is the tested option. |
| Tongue posture matters for children | Partly supported. Mouth breathing, tongue thrust and open bite are linked with growth and bite problems, and assessment can help. |
| Pushing harder gives faster results | "Hard mewing" may cause jaw joint soreness and may push front teeth forward over time. |
| Mewing replaces jaw surgery | No. Significant skeletal differences in adults typically need orthodontics and sometimes orthognathic surgery. |
Where Tongue Posture Does Matter: Children
Although mewing itself is unproven, the general idea that the tongue and breathing influence growth has a reasonable basis in children. During childhood, the jaws are still developing and the tongue acts as a natural internal support for the upper arch. When a child habitually breathes through the mouth, the tongue often sits low in the mouth instead of against the palate. Over time this has been associated with:
- A narrow, high upper arch and crowding
- Crossbites, where upper back teeth sit inside the lower teeth
- A longer lower face
- Open bite, particularly when combined with a tongue thrust habit
The key difference is that in children, the cause is usually something that can be identified and addressed: blocked nasal airways, enlarged tonsils or adenoids, allergies, thumb sucking or a swallowing pattern. A dentist can assess this and, where appropriate, refer to an ENT specialist, orthodontist or myofunctional therapist. Myofunctional therapy uses exercises to retrain tongue and lip habits, and is usually used alongside other treatment rather than on its own.
Orthodontists commonly suggest a first orthodontic check in the early primary school years, which is often a good time to catch these patterns while the jaw is still responsive to growth-guiding treatment.
Tongue Posture in Adults
For adults, good resting tongue posture is still a reasonable habit. Breathing through your nose, keeping your lips gently closed and resting your tongue comfortably on the palate is generally considered normal, relaxed posture. If you notice that you breathe through your mouth much of the time, wake with a dry mouth or snore, it may be worth looking into the cause. Our guide to mouth breathing in adults covers common reasons and when to seek help.
What is unlikely is that resting posture alone will remodel adult bone. In my experience, the more realistic benefit of practising good resting posture is greater awareness of how you breathe and hold your jaw, rather than visible bone change. That is a fair outcome to expect, and there is no harm in gentle, relaxed tongue posture.
The Risks of "Hard Mewing"
Some online videos promote "hard mewing", which involves pressing the tongue forcefully against the palate for long periods, sometimes combined with clenching. This may cause problems:
- Jaw joint and muscle soreness: constant force and clenching can overload the temporomandibular joint and chewing muscles, leading to headaches or jaw pain.
- Tooth movement: sustained tongue pressure against the front teeth may tip them forward and open spaces between them.
- Tooth wear: clenching while mewing can add to wear and sensitivity.
If you develop jaw pain, clicking or headaches, it is a good idea to stop and have your jaw and bite checked.
Evidence-Based Options for Jaw and Bite Concerns
If you are unhappy with your jawline, profile or bite, the right option depends on the cause.
- Crooked or crowded teeth: orthodontic treatment such as braces or clear aligners can straighten teeth and improve how the bite fits together, which can also affect lip support and profile.
- Narrow upper jaw in a child: a palatal expander can widen the arch while the suture is still open.
- Narrow upper jaw in an adult: expansion typically needs bone-anchored devices or surgically assisted expansion, assessed by an orthodontist.
- Significant jaw size or position differences: combined orthodontics and orthognathic jaw surgery may be recommended for skeletal problems that affect function and appearance.
- Soft-tissue jawline definition: body fat, muscle tone and ageing skin play a large role, and these are outside the scope of dental treatment.
Lumi Dental offers clear aligners for suitable patients, and a dentist can assess more complex jaw problems and refer to an orthodontist or oral and maxillofacial surgeon where appropriate. For pricing information, see current deals or ask for a written quote after an examination.
Frequently Asked Questions
Does mewing actually work?
There is no peer-reviewed evidence that mewing changes jaw shape in adults. Tongue posture can matter in growing children, but that is managed through assessment and proven treatment rather than mewing alone.
Can mewing change your jawline as an adult?
It is very unlikely, because adult jaw bones have finished growing and the midpalatal suture is usually fused. Visible jawline changes in photos are more often due to angles, posture, weight or muscle tension.
What is correct tongue posture?
Correct resting tongue posture is generally the tongue resting gently against the roof of the mouth, lips closed and breathing through the nose. It should feel relaxed, not forced.
Is mewing bad for your teeth?
Gentle resting posture is unlikely to cause harm, but forceful "hard mewing" may cause jaw soreness and push front teeth forward. Stop and see a dentist if you notice pain, clicking or new gaps.
Can mewing fix an overbite or crooked teeth?
No evidence shows mewing corrects an overbite or straightens teeth. Orthodontic treatment, such as braces or clear aligners, is the tested approach, sometimes combined with jaw surgery for skeletal problems.
Get Your Jaw and Bite Assessed
If you have been trying mewing because you are unhappy with your jaw, profile or bite, an assessment can explain what is shaping your face and which options are realistic. For children, an early check can pick up mouth breathing, tongue thrust or a narrow arch while growth can still be guided. The team at Lumi Dental in Melrose Park can assess your bite, discuss whether clear aligners may suit you, and refer to a specialist when a case needs it. Visit our general dentist page to book, and see current deals for pricing information and a written quote after your examination.
This article is general information only and is not a substitute for personalised advice from a registered dental practitioner.
