Will Ferrell crashed The Tonight Show in June as anchorman Ron Burgundy and grinned as he called Tuesday his “Mew-day.” Burgundy referenced a radical dental theory swarming social media about sculpting your jawline called Mewing. Its devotees believe that pushing your tongue to the roof of your mouth and holding it there will reshape your jaw to achieve a superhero-like look. The British orthodontist peddling this nonsense is at risk of losing his license to practice in the United Kingdom. His General Dental Council (GDC) professional conduct hearing concludes this week after a two-year inquiry.

Regardless of their ruling, Dr. Michael Mew’s belief in square-jawed perfection has threatened the health and well-being of people around the world. His do-it-yourself “medical” treatment is not just unscientific and dangerous, it draws on racist ideas that are better left in the past.

With his mouth closed, a young man on social media taps his lips twice with his index finger to indicate his silence. He then turns his head to showcase his right profile and runs his finger from his ear down and around the curve of his jaw toward his chin. The TikToker repeats the gesture for the left side of his face. As he models for the camera, he hopes to emit the manly countenance of Hollywood stars and superheroes like Superman. This meme indicating the activity of Mewing has become a viral sensation, reaching children and disrupting classrooms.

Countless satires as well as serious posts state: “I can’t break my mewing streak.” The text is often accompanied by two emojis: one with an index finger over the avatar’s mouth and another with the index finger pointing to the avatar’s masseter muscle. According to social media, the technique necessitates extended periods of silence. Videos joke about guys not answering the phone, even if it is their girlfriend calling, or an unwillingness to dial 911 and speak in an emergency because of Mewing’s importance. The trend is giving new life to the clichéd male personality of the strong, silent type.

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Dr. Mew started this alarming craze. The Mewing missionary and social media star insists that his “organic” method will enhance cheekbones, sharpen jawlines, straighten noses, and realign teeth without braces. Its alleged health benefits include diminishing wrinkles and improving airways to reduce snoring and sleep apnea. The orthodontist has convinced millions that their faces are ugly and unhealthy, and his oral exercise is the nonsurgical solution.

The Independent cited 1.7 billion views of Dr. Mew’s techniques on TikTok. Over 522,800 posts on the platform exist with the hashtag #mewing. His beginner-level video on YouTube tallied 8.2 million views. Dr. Mew’s objective is to sell subscriptions to his app that costs $24.99 a year for curated content. His 96-year-old father, who devised the philosophy and treated patients until the GDC revoked his license in 2017, recently sold a Mewing guide for £2.00 and is offering similar literature to dentists.

Scores of newspaper and magazine articles on both sides of the Atlantic have covered the phenomenon embraced on incel (involuntary celibate) forums like the now shut down SlutHate, a hotbed for misogyny and the objectification of women. Dr. Mew engaged online with these young men who strive to become “Chad,” the perfect man who is essentially Superman by another name.

The 2024 Netflix documentary Open Wide is the latest doorway to the Mew family and their pseudoscientific ideas of facial health. While director Sara Goldblatt refrains from passing judgment on her subjects, the film imparts a disapproving tone. One scene encapsulates the view that Mewing is a religious cult for its two high priests and their disciples. The crew follows Dr. Mew to Wimpole Street where he cosplays as Martin Luther complete with robe and cincture and expresses his desire to nail his own version of the Ninety-five Theses to the GDC door. Just like his father, he imagines himself as a persecuted reformer of the dental orthodoxy.

Mewing’s hold over the imagination is not new. Perceptions of facial beauty and power, which date back to 1772 with Swiss writer Johann Caspar Lavater, and skewed notions of manliness that focused on jaw shape are prominent in Dr. William H. Sheldon’s writings on constitutional psychology. The hereditarian, who graduated from the University of Chicago with a PhD in psychology in 1925 and a medical degree eight years later, preached the idea of body as destiny. He obsessed over the shapes of the chin, nose, and head, which are indicators of manhood. In his four tomes published between 1940 and 1954, the square face and streamlined nose epitomizes not just beauty but white Anglo-Saxon Protestant masculinity and racial superiority.

Dr. Sheldon found proof for his notion in the steel-jawed heroes of the newspaper comic strips, who began appearing in 1929. Tarzan, Dick Tracy, Li’l Abner, and Superman, for instance, constitute the “masculine ideal.” This body type, he argues, “has a broad, square face, with extremely powerful, square jaw, and with firm, sharp, straight muscle lines.” His 1940 text continues to describe the immaculate man, “The nose is long and straight, with a strong high bridge. The head gives the impression of being almost cubical.” Dr. Sheldon replicates this language in his second book. Dr. Mew even retweeted a follower’s meme about Superman’s face as the “scientific” pinnacle of Mewing.

Experts consider Dr. Sheldon one of the greatest villains of eugenic thought in America. His writings, which repackage earlier anthropology of faces and skulls as new science and emphasize racial breeds, are a treasure trove of bigotry. The aim of his 1949 study on Boston area delinquent youth is to thwart “careless reproduction,” which he calls “our most deadly enemy.” Dr. Sheldon favors the words “dog,” “flea,” “mongrel,” “monkey,” and “vermin” for black, mixed race, and “lesser stock” white people. He describes Jewish people as clannish in this book and having shrill voices in his 1942 treatise on temperament. Nude posture photographs that whited out victim’s faces and genitalia (but not their rears) acted as the basis for his studies. His 1954 capstone book is a gallery of naked men. Investigative reporting by The New York Times Magazine compelled the Smithsonian to destroy their cache in 1995.

Regrettably, Dr. Sheldon’s ideas of biological determinism linger online. Images of his three somatotypes—endomorph (obese), mesomorph (muscular), and ectomorph (thin)—and their descriptions are plastered all over the internet as legitimate science. Nutritionists and personal trainers are gaga over his debunked morphology that body-shamed those with nonathletic frames.

So, when you mew, you are connecting to this dark history of racial science. It is not just that the practice has zero evidence of effectiveness, it reinforces the square-jawed masculine ideal perpetuated by racists like constitutional psychologist Dr. Sheldon. The current fixation with the so-called Hollywood visage is the result of projecting a narrow vision of who a hero is and how he is supposed to look. Intentionally or not, Dr. Mew leverages the racialized myth of the square face as the most beautiful and expands it to be the healthiest. Mewers may not know it, but they are reanimating Dr. Sheldon’s hokum that was already present in the cultural milieu. It is time to stop Mewing and idolizing the square jaw as the epitome of masculinity.

Andrew Fogel is a historian of popular culture whose research and writing explores the place of superheroes in the everyday world and the power they hold over the imagination for both kids and adults. He completed his PhD at Purdue University.