Summary
Dr. Sydney McElroy and husband Justin deliver a thorough deep dive into the history and science of mewing on their medical misinformation podcast. The episode traces the origins from Melvin Moss's functional matrix theory through John Mew's orthotropics practice, covering his experiments on his own children -- including spiked headgear, forced pureed diets, and hypnosis -- and how son Mike Mew became the social media face of the movement. Sydney explains the legitimate science around nasal breathing being superior to mouth breathing for dental health and warming air, while clearly distinguishing this from the unsupported claims about adult facial restructuring. The episode covers the Bioblock device, John Mew's loss of his dental license in 2017, and the unfortunate adoption of mewing by the incel and looksmaxing communities. The conclusion: there may be a kernel of truth about childhood jaw development and nasal breathing benefits, but mewing for adult facial transformation lacks evidence.
Key Points
- Mewing originates from John Mew's "orthotropics" -- an alternative to traditional orthodontics that focuses on jaw growth rather than straightening teeth
- Built on Melvin Moss's functional matrix theory that soft tissues influence bone development, which is a legitimate area of orthodontic research
- John Mew experimented on his own three children: one with hypnosis and spiked headbands, one fed only pureed food until age 4, and Mike who became his "orthotropic masterpiece"
- The technique is simply pressing the tongue against the roof of the mouth with lips and teeth together, done constantly
- John Mew lost his dental license in 2017 primarily for publishing materials claiming traditional orthodontists are lying to patients
- Mike Mew took the practice global through YouTube and social media, tying it to celebrity faces and SEO
- Nasal breathing is genuinely superior to mouth breathing for dental health, warming air, and reducing gum disease
- Evidence for treating asthma or COPD through nose breathing vs mouth breathing shows no clear difference
- Anthropological evidence does show ancient skulls tend to have straighter teeth and broader jaws than modern humans
- The technique was adopted by the incel/looksmaxing community after Mike spoke at a "21 Convention" male empowerment event
- John Mew himself admits he only shows successful cases and not his failures
Key Moments
John Mew's disturbing experiments on his own children
A New York Times excerpt reveals John Mew's experiments on his three children. His first son Bill was subjected to hypnosis and a spiked headband to prevent mouth breathing. His daughter Rosie was fed only pureed food until age 4, resulting in severely crowded teeth. Only his middle child Mike, his orthotropic success story, developed the broad jaw Mew was aiming for.
"His first son, Bill, did poorly. He suffered from severe allergies and had so much trouble keeping his mouth shut that John resorted to hypnosis. Though Bill disputes this, John says he created a headband with a spike that poked his son's chin any time he parted his lips."
The actual mewing technique and the Bioblock device
Sydney explains the actual mewing technique: keep mouth shut, lips and teeth together, press tongue into the roof of the mouth, and maintain this constantly. She also describes the Bioblock device -- a retainer-like appliance with spikes that punishes open-mouth posture and includes a heat sensor so orthodontists know if patients are wearing it.
"If you open your mouth you will find that your tongue naturally sits in the floor of your mouth. But what John Mew wants you to do is keep your mouth shut, keep your lips together, your teeth together and press your tongue up into the roof of your mouth. That is mewing."
Nasal breathing is genuinely superior to mouth breathing for health
Dr. Sydney McElroy confirms that nasal breathing is genuinely superior to mouth breathing. It warms and moistens air, protects gum health, and reduces dental caries. However, for chronic lung conditions like asthma and COPD, studies show no clear difference between mouth and nose breathing outcomes.
"There is more warm, moist air so you do not dry out structures as much when you breathe through your nose. And it is better for like dental health and oral health for sure."
John Mew admits he only showcases his successes
Sydney reveals that John Mew himself has admitted to cherry-picking results, saying he only shows pictures of successful cases because showing failures would undermine confidence in the technique. Small studies suggest possible effects but rely heavily on self-reported mouth breathing, making rigorous research extremely difficult.
"John Mew himself has said like, well, I put up pictures of my successes, but I don't put up pictures of all my patients because you would see the ones that it didn't work on and you would say, see, it doesn't work. So I just don't put them up."
