There is no scientifically established timeline for mewing results because no clinical studies have tested the technique or measured its outcomes. The timelines you see online, often ranging from six months to two or more years, come entirely from self-reported anecdotal claims on social media. Understanding why those timelines are unreliable, and what the science actually says about changing facial bone structure, can help you set realistic expectations.
What Mewing Claims to Do
Mewing involves resting the entire tongue flat against the roof of the mouth, with lips sealed and teeth lightly touching. The idea is that sustained pressure from the tongue will gradually widen the upper jaw (the maxilla) and push the midface forward, producing a more defined jawline and improved facial proportions over time.
The concept draws loosely from a real principle in orthodontics called the functional matrix theory. Your dental arches sit in an equilibrium of forces: the cheeks and lips push inward, while the tongue pushes outward. When that balance shifts, as it does in chronic mouth breathers whose tongues rest low, facial growth patterns can change. Children who breathe through their mouths tend to develop longer faces, narrower palates, and receding chins. This association between tongue posture and facial development in growing children is well documented. Mewing extrapolates from this and assumes that consciously repositioning the tongue can reverse or redirect those patterns, even in adults.
Why No One Can Give You a Real Timeline
The honest answer is that no controlled study has ever measured what happens to facial bone structure when adults practice mewing for any length of time. The American Association of Orthodontists has stated directly that there is no current research suggesting mewing provides any benefit to your jawline or oral health, calling the scientific evidence behind its claims “as thin as dental floss.”
The timelines floating around online, six months for subtle changes, one to two years for noticeable shifts, three or more years for dramatic results, are based on before-and-after photos shared by individuals. These comparisons are extremely easy to manipulate. Differences in lighting, camera angle, head tilt, and even whether your jaw is slightly open or closed can dramatically alter how your face looks in a photo. Many early “results” people share are simply the visual effect of learning to engage the back of the tongue, which tightens the skin under the chin and creates the appearance of a sharper jawline without any bone change at all.
What Bone Remodeling Actually Requires
Changing the shape of facial bones is genuinely difficult, even with professional orthodontic tools. Over a century of research in orthodontics shows that growth modification of the face happens only within narrow limits, typically a few millimeters at most. And those results require heavy, precisely directed mechanical forces applied with professional appliances.
Age matters enormously. In children under eight or nine, the palate can be widened with relatively light force because the midpalatal suture (the seam running down the center of the roof of the mouth) hasn’t fused yet. During adolescence, widening the palate requires heavy forces that create microfractures along that suture. After adolescence, the suture is fully fused, and expanding the maxilla requires surgery. The gentle, diffuse pressure of a tongue resting against the palate is a fundamentally different force than what orthodontic devices deliver, and there is no evidence it can remodel fused adult bone.
This is the core problem with mewing timelines. The biological mechanism that would make it work in adults hasn’t been demonstrated. Telling someone to mew for two years assumes that the technique works at all, which remains unproven.
What You Might Actually Notice
People who start mewing do report some changes in the first weeks and months, but these are soft tissue and postural changes, not skeletal ones. Learning to keep the tongue on the palate and the mouth closed can improve your resting posture: your chin tucks slightly, your neck straightens, and the submental area (the soft tissue under the chin) looks tighter. These changes can genuinely improve how your face looks in photos and in the mirror, but they happen because you’re holding your head differently and engaging muscles you weren’t using before.
Some people also report improved nasal breathing, reduced snoring, and greater awareness of their tongue and jaw positioning throughout the day. These are reasonable outcomes of paying more attention to oral posture. They are not evidence of bone remodeling.
Risks of Doing It Wrong
Mewing is not entirely harmless. Applying uneven tongue pressure, pushing too hard, or forcing the tongue into an uncomfortable position can cause real problems. Excessive or asymmetric pressure on the teeth can push some teeth forward while leaving others in place, creating gaps or crooked teeth over time. It can also change how your upper and lower teeth meet, potentially causing bite problems like underbites, overbites, or open bites.
The most common complaint is jaw pain. Forcing a new tongue posture can strain the temporomandibular joint (the hinge connecting your jaw to your skull), leading to TMJ pain, clicking, headaches, and difficulty chewing. Speech difficulties have also been reported. The American Association of Orthodontists does not recommend any attempts to move teeth or align jaws without professional supervision.
What the Evidence Actually Supports
Good tongue posture, resting the tongue on the roof of the mouth, breathing through the nose, and keeping the lips gently closed, is considered the normal, healthy resting position of the mouth. Practicing it is not controversial. What is controversial is the claim that doing so will reshape your adult skeleton in a visible way.
If you’re concerned about the structure of your jaw, the width of your palate, or your facial profile, orthodontists and oral surgeons have evidence-based tools that produce measurable, predictable changes. Palatal expanders, orthodontic appliances, and orthognathic surgery have decades of clinical data behind them, with clear timelines and expected outcomes. Mewing, at this point, does not.
Maintaining good tongue posture is a reasonable habit. Expecting it to sculpt your jawline on a specific schedule is not supported by any current science.