What is mewing and does it work?

What is mewing and does it work?

Mewing is a tongue posture practice that claims to reshape the adult jaw and face through consistent placement of the tongue against the roof of the mouth. The term was coined by Dr. John Mew, a British orthodontist who developed a theoretical framework called orthotropics in the 1970s and 1980s. His ideas gained viral attention on TikTok and YouTube between 2018 and 2024, where influencers promised followers that learning how to mew correctly would produce a sharper jawline, higher cheekbones, and better facial symmetry in six to twelve months.

The clinical evidence tells a different story. A 2018 Cochrane systematic review found that myofunctional therapy (the clinical practice underlying mewing) can guide facial development in children with growing dentition, but the review examined only pediatric populations during active growth phases. Multiple systematic reviews confirm that skeletal changes in adults require surgical intervention, not tongue exercises. The growth window for facial bone remodeling closes after adolescence. Tongue posture does not reverse this timeline.

This review synthesizes ten published clinical studies, including two systematic reviews of randomized controlled trials and case documentation from the orthotropics literature. We did not test mewing techniques in-house. The verdict is consistent across all sources: myofunctional therapy works in children during active growth, and it does not work for structural changes in adults.

What mewing claims to do for your jawline

Social media tutorials present mewing as a simple, free alternative to cosmetic dentistry or surgery. The typical protocol instructs users to press the entire tongue (not just the tip) flat against the palate, close the lips, breathe through the nose, and hold this position throughout the day. Proponents claim that consistent tongue pressure over months will reshape the maxilla (upper jaw), widen the dental arch, move the mandible (lower jaw) forward, sharpen the jawline, lift the cheekbones, correct a recessed chin, and reduce the appearance of a double chin.

The most popular mewing videos promise visible results within three to six months for teenagers and six to twelve months for adults. Many creators explicitly claim that age is irrelevant because “bone is always remodeling.” Some tutorials label mewing as a reversal technique for mouth breathing damage, asserting that years of incorrect tongue posture caused the facial structure problem and years of correct posture can undo it.

These claims rest on a theory published by Dr. John Mew in the early 2000s, which proposed that facial structure is primarily determined by habitual oral posture and breathing patterns rather than genetics. A 2004 philosophical review and a 2007 twin case study form the published foundation of orthotropics. The case study compared one twin who received orthotropic treatment to a control twin who did not, but the study lacked randomization, blinding, or control for environmental variables outside the intervention. The paper did not establish causality, and no subsequent controlled trials have reproduced the findings in adults.

The evidence for facial changes works only in children

Clinical myofunctional therapy, when applied in a supervised orthodontic setting to children during active growth, shows measurable effects on dental arch development and some skeletal dimensions. A 2018 Cochrane systematic review analyzed randomized controlled trials of myofunctional appliances in children with Class II malocclusion (where the lower jaw sits behind the upper jaw). The review found that functional appliances can guide mandibular growth forward during the pubertal growth spurt, reducing the skeletal discrepancy by 1 to 2 millimeters on average. The effect size is small, and the evidence applies only to children with remaining growth potential, defined as pre-peak or peak skeletal growth phases measured by hand-wrist radiographs or cervical vertebral maturation.

A 2016 randomized controlled trial enrolled children aged 7 to 11 with anterior open bite and tongue dysfunction. Half received eight months of supervised orofacial myofunctional therapy, including tongue posture correction, lip seal exercises, and swallowing retraining. The treatment group showed significant improvement in bite closure and tongue posture compared to controls. The study explicitly noted that all participants were in active dental development and that results could not be extrapolated to adults with completed skeletal growth.

A 2025 umbrella review of systematic reviews confirmed that functional orthopedic appliances produce skeletal changes in growing patients but emphasized the growth-timing dependency. Appliances worn after the pubertal growth spurt show negligible skeletal effect. A 2025 systematic review of tongue posture strategies in orofacial myofunctional therapy found that interventions targeting tongue position improve swallowing function and dental outcomes in children, but no included studies examined adult skeletal remodeling.

The table below contrasts internet mewing practices with clinical myofunctional therapy as described in the published trials:

The key finding across all clinical literature is timing. Myofunctional therapy can guide facial growth in children during active development. In adults, the growth window has closed and skeletal changes require surgery, not tongue posture.

Adult jaws don’t remodel from tongue posture

Multiple systematic reviews confirm that skeletal malocclusions in adults do not respond to non-surgical interventions. A 2022 systematic review and meta-analysis examined treatment of skeletal Class II malocclusion in adults (where the lower jaw sits too far back). The review found that functional appliances had no measurable effect on adult skeletal dimensions. Clinically significant correction of jaw position required orthognathic surgery, which physically repositions the jaw bones through surgical cuts and fixation plates. The review concluded that skeletal maturity is a biological boundary for non-surgical facial remodeling.

A 2022 systematic review of adult skeletal Class III malocclusion (where the lower jaw protrudes forward) reached the same conclusion. Surgical correction was the only intervention that produced skeletal changes in adults. The authors noted that some adult patients experience minor dental compensation (tooth tilting) from orthodontic appliances, but this is not the jaw repositioning that mewing tutorials promise. Dental compensation does not change the underlying bone structure or facial profile.

The reason is straightforward. Facial bones grow at sutures, which are fibrous joints between skull bones. During childhood and adolescence, these sutures remain open and responsive to mechanical forces, which is why orthodontic appliances and myofunctional therapy can guide growth direction. After puberty, the sutures fuse and become rigid bony unions. Tongue pressure is not sufficient force to reopen fused sutures or remodel mature cortical bone. The maxillary sutures fuse in late adolescence (typically age 15 to 17 in females, 17 to 19 in males), and mandibular growth plates close by age 18 to 20. Once fusion is complete, skeletal changes require controlled surgical fracture and repositioning.

What about bone remodeling? It is true that bone tissue constantly remodels at the cellular level through osteoclast resorption and osteoblast deposition. This process maintains bone health and repairs microfractures, but it does not change macroscopic skeletal architecture in the absence of significant mechanical load or metabolic disease. Orthodontic tooth movement relies on localized bone remodeling under sustained pressure from brackets and wires (typically 20-50 grams of force per tooth, applied 24 hours per day for months). Tongue posture does not generate equivalent force magnitude, direction, or duration on the skeletal structures, and even if it did, the fused sutures prevent the shape change that mewing promises.

What are the risks of mewing without guidance?

The most common harm from DIY mewing is delayed or foregone orthodontic care. Adults who spend months or years attempting tongue posture correction for a skeletal problem may miss the window for less invasive interventions or fail to address the underlying cause of their concern (which may be dental misalignment treatable with braces, a breathing disorder requiring medical evaluation, or a skeletal issue requiring surgical consultation). Time spent on ineffective self-treatment delays appropriate diagnosis.

Incorrect technique can cause temporomandibular joint discomfort. Some mewing tutorials instruct users to press the tongue upward with significant force or to hold the jaw in a protruded position. Sustained abnormal jaw posture can strain the TMJ capsule, masticatory muscles, and associated ligaments. A 2004 review by the orthotropics founder noted that improper oral posture can contribute to TMJ disorders, but the paper was a philosophical overview, not an empirical study, and it did not validate the proposed treatment.

Social media tutorials lack individualized assessment. Facial structure and occlusion vary widely. A tongue posture that is neutral for one person may be maladaptive for another depending on palate shape, tongue size, tonsil hypertrophy, nasal airway patency, and dental alignment. Clinical myofunctional therapy begins with a comprehensive evaluation by a trained professional who can identify contraindications (such as severe skeletal discrepancy requiring surgery, or airway obstruction requiring ENT referral). DIY mewing bypasses this screening.

False hope is a harm. Adults who invest months in mewing based on viral promises of jaw reshaping may experience disappointment, frustration, and erosion of trust in evidence-based care when the promised changes do not materialize. This psychological burden is not trivial, particularly for individuals with body dysmorphia or significant distress about facial appearance, who would benefit from counseling or appropriate medical referral rather than unproven self-treatment.

When tongue posture correction actually matters

Tongue posture does matter in specific clinical contexts, all of which involve professional evaluation and supervision. Orofacial myofunctional therapy is a legitimate field of clinical practice focused on correcting abnormal muscle function in the face, mouth, and throat. Certified orofacial myologists work with orthodontists, dentists, and speech-language pathologists to address functional problems that impair breathing, swallowing, speech, or dental development.

Mouth breathing is one context where tongue posture correction plays a role. A 2025 systematic review and meta-analysis found a significant correlation between habitual mouth breathing and altered craniofacial morphology in children, including increased lower facial height, narrower maxillary arch, and higher palatal vault. The review emphasized that these changes occur during pediatric growth windows when the face is actively developing. Myofunctional therapy in combination with treatment of the underlying cause of mouth breathing (such as enlarged adenoids, allergic rhinitis, or nasal septal deviation) can help restore nasal breathing and may prevent or mitigate some developmental changes. A 2023 observational study confirmed the association between mouth breathing and dental malocclusion in school-aged children, but the study design could not establish whether correcting breathing patterns reverses existing facial changes in adults. The evidence supports intervention in children, not retrofitting in adults.

Tongue thrust and abnormal swallowing patterns are another context. Children who habitually push the tongue forward between or against the teeth during swallowing may develop anterior open bite or spacing problems. Myofunctional therapy retrains the swallowing pattern, which can stabilize orthodontic treatment results and prevent relapse. This is a functional correction (training a muscle pattern) rather than a structural change (remodeling bone). The therapy addresses the behavior that contributes to dental misalignment, not the bone structure of the jaw.

Speech therapy sometimes includes tongue posture exercises for articulation disorders. Correct tongue placement at rest and during speech sounds can improve clarity for certain phonemes. Again, this is a neuromuscular re-education targeting a functional skill, not skeletal remodeling.

If you are concerned about your jaw position, facial structure, breathing quality, or dental alignment, the appropriate first step is evaluation by a dentist, orthodontist, or physician. An orthodontist can assess skeletal relationships with clinical examination and imaging, determine whether you have remaining growth potential (relevant only in adolescence), and recommend evidence-based treatment options, which may include braces, clear aligners, functional appliances (in adolescents), or surgical referral (in adults with skeletal discrepancies). If a breathing issue is suspected, an otolaryngologist can evaluate nasal airway obstruction, enlarged tonsils or adenoids, or other anatomical causes of mouth breathing. If myofunctional therapy is appropriate for your case, your orthodontist or dentist can refer you to a certified orofacial myologist who will provide individualized, supervised therapy rather than generic social media instructions.

Tongue posture correction is not a cosmetic shortcut and it is not a substitute for orthodontic or surgical treatment in adults. The clinical evidence is clear: skeletal changes from myofunctional therapy occur in children during active growth, and the growth window closes after adolescence. Adults seeking jaw or facial changes should pursue evaluation by qualified professionals who can offer interventions supported by controlled trials, not viral trends that contradict developmental biology.