What Is Mewing and Where Did It Come From?
Mewing is the practice of maintaining specific tongue posture where the entire tongue rests flat against the roof of the mouth, with lips sealed and teeth lightly touching. The technique is named after Dr. John Mew and his son Dr. Mike Mew, British orthodontists who developed the theory of orthotropics, which proposes that facial bone structure is significantly influenced by tongue posture, breathing patterns, and oral habits throughout life.
The practice went viral on social media beginning in 2018 when before-and-after photos and transformation videos accumulated millions of views. Proponents claim that mewing can widen the palate, define the jawline, improve cheekbone prominence, and even restructure the midface. These are extraordinary claims, and the evidence behind them requires careful examination.
The Orthotropic Theory: What Science Supports
The foundational principle behind mewing has legitimate scientific backing. Wolff’s Law, established in the 19th century, states that bone remodels in response to the mechanical loads placed upon it. The tongue exerts approximately 500 grams of force against the palate during swallowing, and research in the European Journal of Orthodontics confirms that tongue posture influences maxillary (upper jaw) development during childhood and adolescence.
Studies on children with chronic mouth breathing demonstrate significant differences in facial development compared to nasal breathers. Research published in the American Journal of Orthodontics and Dentofacial Orthopedics found that children who breathe through their mouths develop narrower palates, longer faces, recessed jaws, and less defined cheekbones. This evidence strongly supports the principle that oral posture affects craniofacial development in growing individuals.
The critical distinction, however, is between children with active growth plates and adults with fused cranial sutures. The midpalatal suture typically fuses between ages 15 and 18 in females and 20 to 25 in males. After fusion, the ability to reshape bone through light pressure alone becomes extremely limited.
What Adults Can Realistically Expect
The before-and-after photos circulating online often show changes that could be attributed to multiple factors: weight loss reducing submental (under-chin) fat, improved posture lifting the jaw, better lighting or camera angles, natural maturation in younger adults, or the placebo effect of increased body awareness.
Adults who practice mewing consistently may experience soft tissue changes that improve facial appearance without actual bone remodeling. These include improved jaw posture from conscious positioning, reduced double chin appearance from better head and neck alignment, slight improvement in cheekbone visibility from reduced facial puffiness (potentially from improved nasal breathing and reduced fluid retention), and better resting facial expression from reduced mouth breathing.
A study in Cranio: The Journal of Craniomandibular Practice examined the relationship between tongue posture and hyoid bone position in adults and found that changes in habitual tongue posture could alter the perceived jawline by repositioning soft tissue structures, even without skeletal changes.
Proper Mewing Technique
The correct tongue position involves placing the entire tongue surface against the palate, not just the tip. The tip of the tongue should rest just behind the upper front teeth without touching them. The middle and back thirds of the tongue should press gently upward against the soft palate.
Lips should remain sealed at rest, with breathing occurring exclusively through the nose. Teeth should be in light contact or very slightly apart, with no clenching. The jaw should be relaxed with the masseter muscles (the muscles you feel when you clench your teeth) inactive.
Swallowing should occur using tongue pressure against the palate rather than facial muscles. Many people habitually use their cheeks and lip muscles to create negative pressure during swallowing, which is the pattern mewing practitioners aim to correct.
Common mistakes include only pressing the tongue tip against the palate, clenching the jaw forcefully, pressing the tongue against the front teeth (which can cause orthodontic movement), and creating tension in the neck muscles.
Timeline for Noticeable Changes
For adolescents under 18, visible changes in palatal width and facial proportion may occur within 6 to 12 months of consistent practice, particularly when combined with nasal breathing and proper chewing habits. This aligns with active craniofacial growth periods.
For adults ages 18 to 25 with partially fused sutures, subtle changes in jawline definition from postural improvement may become apparent within 3 to 6 months. Any skeletal changes would be minimal and difficult to distinguish from soft tissue changes.
For adults over 25, skeletal changes from mewing alone are not supported by evidence. Postural improvements in the jaw and neck may create visible changes within 1 to 3 months, primarily from improved alignment rather than bone remodeling.
Consistency is essential regardless of age. Mewing must become a habitual tongue position maintained throughout the day, not a practice performed for a few minutes at a time. The tongue should rest in the correct position during all waking hours and, ideally, during sleep as well.
What Mewing Cannot Do
Mewing cannot correct significant skeletal malocclusion (misaligned bite) in adults. Conditions like mandibular retrognathia (recessed lower jaw), severe overjet, or skeletal open bite require orthodontic treatment or orthognathic surgery.
It cannot replicate the effects of orthognathic surgery, which physically repositions the jaw bones. The changes produced by mewing, even in best-case scenarios, are measured in millimeters over months to years, while surgical correction produces centimeter-scale changes immediately.
Mewing also cannot compensate for genetic jaw structure. If your family lineage features narrow palates or recessed jaws, tongue posture alone is unlikely to overcome the genetic blueprint, particularly after growth has ceased.
The Role of Chewing and Overall Oral Function
Proponents of mewing often recommend hard chewing (using products like mastic gum or falim gum) to develop the masseter muscles and stimulate jaw bone density. Research in the Archives of Oral Biology confirms that masticatory forces do influence mandibular bone density, and individuals with stronger bite forces tend to have more angular jaw shapes.
However, excessive hard chewing carries risks including temporomandibular joint (TMJ) dysfunction, masseter hypertrophy causing an undesired widening of the lower face, and tooth wear. If incorporating chewing exercises, limit sessions to 10 to 15 minutes daily and stop immediately if jaw pain develops.
Frequently Asked Questions
Does mewing work for adults over 30?
Skeletal changes from mewing in adults over 30 are not supported by clinical evidence. However, improved tongue posture, nasal breathing, and postural alignment can create subtle visual improvements in jawline definition and facial profile. These are soft tissue and postural changes, not bone remodeling.
Can mewing cause TMJ problems?
If performed incorrectly, yes. Pressing the tongue too forcefully, clenching the jaw, or maintaining asymmetric pressure can aggravate or cause temporomandibular joint dysfunction. The correct technique involves gentle, sustained pressure without forceful clenching.
How does mewing compare to jawline fillers or surgery?
Mewing produces subtle, gradual changes primarily through postural improvement. Dermal fillers provide immediate but temporary enhancement. Orthognathic surgery offers permanent skeletal repositioning but involves significant recovery. The appropriate choice depends on the severity of the concern and individual goals.
Should children practice mewing?
Encouraging proper tongue posture and nasal breathing in children is supported by orthodontic research and may reduce the need for future orthodontic treatment. Pediatric dentists and orthodontists can evaluate whether a child would benefit from myofunctional therapy, which is the clinical version of the principles behind mewing.
