John Mew (born in 1928) is a British orthodontist. He is the founder of orthotropics and mewing. Orthotropics is a form of oral posture training that claims to guide facial growth and is not supported by mainstream orthodontists. John Mew's son Michael Mew (born c. 1969) is also an orthodontist and has also practised and promoted the idea of orthotropics.

Mew was educated at Rose Hill preparatory school in Tunbridge Wells (1935–1942) and then at Tonbridge School (1942–1945). He subsequently graduated in dentistry at University College London (1948–1953), and then trained in orthognathic surgery at Queen Victoria Hospital in East Grinstead (1953–1956). He has written two textbooks and published many articles internationally on this subject. He became president of the Southern Counties Branch of the British Dental Association in 1971. Since around 2000, he has spent much of his time lecturing about his techniques. Currently he is a professor of orthotropics at the London School of Facial Orthotropics.

Mew held a two-year visiting professorship at Victor Babeș University of Medicine and Pharmacy in Timișoara, Romania. He was honoured with life membership of the British Dental Association in 1999.

Orthotropics is Mew's orthodontic method claimed to be able to guide facial growth. Mew's orthodontic methods have consisted of widening and advancing the upper jaw using palatal expanders, changing the patient's diet, and having the patient adopt a myofunctionally correct resting place for the tongue, where he argues it provides an outward force able to laterally expand the upper jaw in a growing child, and prevent downward and backward growth of the maxilla, gradually resulting in a 'natural' cure of the malocclusion.

Mew believes that the etiology of malocclusion is environmental and that environment decides whether or not teeth are crooked. In contrast, mainstream orthodontics attributes crooked teeth primarily to genetics.

Mew became concerned by the orthodontic outcomes of some of his patients. He concluded that the mechanics of orthodontic treatment, while straightening the teeth, did not address the underlying cause of the dental overcrowding and, in some cases, caused facial damage. He concluded that extractions, fixed appliances with elastics and retractive headgear could be harmful to facial growth. In 1958 John Mew put forward The Tropic Premise, which argued that malocclusion was a 'postural deformity', that overcrowded teeth were not necessarily inherited and that, consequently, malocclusion could be avoided with early intervention to correct oral posture and function.

As part of his search for an approach to orthodontics that did not cause facial retraction, John Mew visited Rolf Fränkel in East Germany in 1968, who introduced him to the work of Konstantin Buteyko. Mew went on to develop the concept of facial growth guidance, which he called Orthotropics, and the Biobloc system of treatment, involving the use of a palate expanding appliance followed by a postural appliance. He practiced Orthotropics for 30 years and was involved in founding the International Association of Facial Growth Guidance in 1987 in Fort Worth, Texas.

"Mewing" is a form of do-it-yourself oral posture training named after John Mew and his son Michael Mew (born c. 1969) and is described most simply by Mew as "stand up straight and shut your mouth". Mewing grew in popularity, was shared on social medias by influencers and received mainstream media coverage in 2019. This coverage included many tabloid papers and an interview with John Mew’s son Michael on This Morning with Eamonn Holmes. A noticeable role in the popularization of mewing was played by before-and-after photos published on Reddit (e.g., in its r/Mewing subreddit) which have spread to other social networks like TikTok and claim to prove the effectiveness of mewing.

Although Mew's theory contains some plausible conclusions, there is inadequate evidence to support the efficacy of this treatment. Therefore, it is not considered a viable alternative treatment to orthognathic surgery.

John Mew's views on the aetiology and best treatment process for malocclusion have met opposition from mainstream British orthodontists. Mew was fined by the NHS for providing inappropriate treatment. He appealed against the then Minister of Health in the High Court in 1987 and Lord Justice Murray Stuart-Smith judged that "these very serious strictures were wholly unwarranted and perhaps go some way to justify the applicant's doubts as to the impartiality of the Dental Services Committee". He found in favour of Mew and awarded costs.

In 2010, the General Dental Council (GDC), a London-based organisation that regulates dental professionals in the United Kingdom, reprimanded Mew for running advertisements that it said contained misleading assertions. The GDC said Mew had "denigrated orthodontics and falsely alleged that the GDC had accepted the truth of Mr Mew's report". Mew characterized the investigation and reprimand as an effort to suppress his theories. Mew did not dispute the charge and referred to himself as a "whistleblower".

Mew's son, Michael Mew, has asserted that his father and his theories had been treated badly by the profession. In a unanimous decision around 2019, Michael Mew was expelled from the British Orthodontic Society for continuing to advocate his positions. He launched a petition campaign to argue for a repeal of the decision. As of June 2024, he was still registered as an orthodontist with the GDC.

John Mew has spent most of his life actively advocating for a reduction in orthognathic surgery and ensuring patients knew about less invasive alternatives before consenting to surgery. He started his career as an orthognathic surgeon and came to believe that most cases relapsed or did not serve the patient well. He advocates simple maxims that align with paleoanthropological view on developing good jaws and teeth: breathe through your nose, not your mouth; chew hard food; stand up straight.

One aspect upset me more than any other; unnecessary surgery. As you will see from the cases demonstrated in this book, Orthotropics is able to avoid the need for orthognathic surgery in almost every case. At the end of the last millennium it was thought that in Britain, about 1000 children and young adults received orthognathic surgery a year but in 1999 a survey suggested that 7% of a consultant Orthodontist’s workload was related to Orthognathic treatment and in 2009 it was estimated that 1.5 million people would warrant orthognathic treatment. I think that this increase is partly driven by an acceptance within current orthodontic practice that most class II malocclusions with overjets of over four millimetres will require surgery.

Orthotropics frequently corrects overjets of over ten millimetres. This of course is of importance when we are considering ‘Informed Consent’ as all patients who have been told they require jaw surgery should also be told if there are non-surgical options. Unfortunately the orthodontists for reasons of their own, have convinced the GDC that orthotropics is no more effective than Functional or Orthopaedic appliances. To me this is not Fully Informed Consent as it should be the patient who decides whether to have surgery not the clinician.

— John Mew, The Cause and Cure of Malocclusion, 2nd ed. (2013), p. 22

Mew argues that orthodontic patients in the UK are not given fully informed consent, because they are not told about alternative treatment methods such as orthotropics. This culminated in Mew taking out a newspaper advertisement to proclaim his opinion that the General Dental Council suppressed information about alternatives. In 2010 the GDC reprimanded Mew for accusing the GDC of promoting surgery for jaw misalignment when there were non-surgical alternatives available.

Aged 18, shortly after the end of the Second World War, Mew learnt to fly a de Havilland Tiger Moth biplane. He subsequently took up fixed-wing gliding and later hang gliding. At 19 he built his own sports car, fabricating much of it from scratch. Between 1957 and 1967 he was involved in motor racing, moving from Formula Three to Formula One. He was one of the last private entrants, entering events all over Europe. In 1963 he twice broke the Formula One club circuit record at Brands Hatch, beating times set by world champions Jim Clark, and John Surtees. In 1958 he was selected for the British Team for the first post-war challenge for the Americas Cup, though he was subsequently unable to participate in the event itself. In 1971, he was selected to crew for John Prentice, captain for the British International 14 dinghy racing team in Annapolis, Maryland, where Britain came second. John Mew and his crew Michael Moss took second place at an International 14 World Championships anniversary event.

Between 1993 and 1999, Mew built a reproduction moated castle in a valley in Sussex, which was featured on the TV programme Britain's Best Home.