Mewing is a tongue posture technique that went viral on TikTok, where users claim it can reshape the jawline, sharpen cheekbones, and improve overall facial structure. The practice involves pressing your tongue flat against the roof of your mouth and holding it there throughout the day. It has accumulated billions of views across social media, particularly among young men looking for a more defined jaw. But despite the hype, no scientific evidence supports the idea that mewing changes adult bone structure, and orthodontic professionals warn it can cause real dental problems.
How Mewing Works on TikTok
TikTok creators typically demonstrate mewing with before-and-after photos or videos, often filmed weeks or months apart, showing what appears to be a more chiseled jawline. The instructions are simple: close your mouth, let your teeth rest gently together without clenching, and flatten your entire tongue against the roof of your mouth. The tip of your tongue sits just behind your front teeth without touching them. You hold this position as much as possible during the day, sometimes for months or years.
The trend took off because it promises facial changes without surgery, braces, or money. Creators frame it as a “natural” hack, a free alternative to cosmetic procedures. Many videos pair it with other “looksmaxxing” techniques (another TikTok term for self-improvement focused on physical appearance), positioning mewing as one piece of a broader aesthetic routine.
Where the Technique Actually Comes From
Mewing is named after British orthodontist John Mew, who developed the idea in the 1970s as part of a practice he called “orthotropics.” He believed that proper tongue posture could correct misalignments in the teeth, jaw, sinuses, and overall facial structure. He also thought it could help with sleep apnea, breathing problems, and speech issues. His son, Mike Mew, continued promoting the technique and built a large YouTube following, which eventually fed the TikTok explosion.
Mike Mew’s professional history is worth knowing. He was expelled from the British Orthodontic Society for posing harm to child patients who underwent his treatments. In November 2024, the UK’s General Dental Council ordered him erased from the dental register, effectively ending his ability to practice dentistry in Britain. He has appealed the decision, and his registration is currently listed as suspended through 2124. This doesn’t automatically mean the technique is dangerous, but it does tell you something about how the dental profession views the claims behind it.
What the Evidence Actually Shows
There are no peer-reviewed studies demonstrating that mewing reshapes adult facial bones. The core claim, that sustained tongue pressure can move the upper jaw (the maxilla) outward and forward, has no scientific backing in adults whose facial bones have fully developed. Bone remodeling in adults requires significant mechanical force, far more than a tongue can generate.
The before-and-after photos on TikTok are largely explained by other factors: changes in lighting, camera angle, body fat percentage, normal aging and maturation (many creators are teenagers whose faces are still developing), and the simple difference between a relaxed jaw and a deliberately clenched one. Posture changes can also shift how the jaw looks in photos without changing the bone underneath.
Risks of Practicing Mewing
The American Association of Orthodontists has specifically warned that forcing your tongue into unnatural positions can backfire. Mewing applies pressure to the teeth and jaw, and if that pressure isn’t perfectly even across the palate, it can push some teeth forward while leaving others in place. The result: crooked teeth, new gaps, or a bite that didn’t have problems before.
Uneven tongue pressure can also cause malocclusion, meaning your upper and lower teeth no longer line up correctly. That includes underbites, overbites, and open bites. A misaligned bite places stress on your jaw joints, potentially triggering temporomandibular joint (TMJ) pain, clicking, and difficulty opening your mouth fully. It can also change how air flows through your mouth, leading to speech difficulties.
Perhaps the most frustrating outcome: if mewing creates or worsens these problems, fixing them often requires professional treatment that’s more complex and time-consuming than it would have been otherwise. You can end up needing orthodontic work to reverse damage from a technique that was supposed to replace orthodontic work.
What Actually Changes Jaw Structure
If you genuinely have a narrow upper jaw or bite problems, orthodontists have real tools for that. A palate expander is an oral device that fits in the roof of your mouth and gradually moves both halves of your upper jawbone apart. Unlike mewing, these devices apply controlled, measurable force and are monitored by a professional.
For adults whose facial bones are fully developed, surgically assisted palate expanders or implant-supported expanders can achieve what tongue pressure cannot. These apply force directly to the bone rather than to the teeth. Palate expansion has documented benefits beyond appearance: widening the nasal cavity reduces nasal airflow resistance, and some studies show it helps with obstructive sleep apnea. Braces can move teeth, but they can’t move jawbone. That distinction matters, because mewing’s central promise is about bone, not teeth.
For people who just want a more defined jawline without a medical issue to correct, the honest answer is that body fat percentage, genetics, and normal facial maturation are the biggest factors. Losing body fat reveals more jaw definition. Aging from your teens into your mid-twenties naturally sharpens facial features as baby fat recedes. Neither of those requires pressing your tongue against your palate for hours a day.