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Illustration by Eric Cash
Choosing a dental professional should never be as painful as a trip to the dentist’s office. With this in mind, topDentists research group polled area dentists, asking, “If you had a patient in need of a dentist, which dentist would you refer them to?” The result: nearly 250 outstanding dentists, as chosen by their peers.
SLM also examined other issues, including the psychology behind a smile, engineering developments in dentistry, and local efforts to make less fortunate children grin.
THE ORIGINAL EMOTICON
We no longer take smiles for granted. We’ve realized how complicated they are…and how much they matter.
By Jeannette Cooperman
A smile can be an invitation, a dismissal, or the prelude to a kiss. We smile when we’re happy—or want to seem so.
Smiling can win us friends and promotions and alter our psyche.
Is it any wonder people slap on braces at midlife, smear bleach on their coffee-stained teeth, puff up their lips with injections of a powerful neurotoxin, and buy porcelain veneers pricier than Limoges?
“Smiles are important signs of social approval,” explains Dr. C. Robert Cloninger, a Washington University psychiatrist and geneticist known for his work on personality development and wellbeing. “They play a crucial role as a signal of friendship or social interest, whereas frowning puts people off or expresses disapproval. So smiles stimulate and maintain the formation of social bonds. Smiles can also be a sign of happiness—and the use of humor to cope with life’s many difficulties and disappointments. So smiling can be a sign of maturity and healthy adaptive functioning.”
A baby’s first smile might occur in the middle of the night—and it might just be gas. But after a month of adults bending over the cradle and grinning like saps at every spontaneous smile, babies learn the social smile. At first, they’re probably just copying their parents, echoing their joy and thus learning how it feels to be happy. Eventually, though, it dawns on them that whenever they smile and gurgle at us, they make us happy. At that point, a smile becomes a baby’s version of a stand-up comedian’s fallback joke.
Babies’ smiles are the genuine sort, pulling up their cheeks into little apples and squinching their eyes. We now call such an expression a Duchenne smile—after the 19th-century French neurologist Guillaume-Benjamin-Amand Duchenne, who first isolated the muscle contractions involved in the most basic and sincere human facial expressions.
Last year, researchers at the University of California, Berkeley published a list of six archetypal smiles, starting with the Duchenne grin and moving on to the coy, flirty smile that’s paired with a direct gaze, even though the body is turned slightly away or the head tilted down.
Next came the amused smile, which lingers after a hearty laugh or catches a bit of irony that no one else noticed.
“If you’re making one of these smiles, you don’t necessarily want to approach the other person to meet their needs,” neurologist Emiliana Simon-Thomas told reporters last October, when the study was released. The other three smiles surveyed, though, were proactive: The love smile, offered with a tilted head and soft eyes, seeks intimacy; the interested smile, with raised eyebrows and a slight grin, asks for details or to be included in the game; the embarrassed smile, sometimes with eyes downcast, begs forgiveness.
We’re All Mona Lisa
A simple smile—one that does not raise the cheeks or squinch the eyes—might be a cautious overture, or it might be fake, a smile deliberately summoned to smooth an obligatory social interaction.
Paul Ekman, who was named one of the most influential psychologists of the 20th century by the American Psychological Association, is the master of the micro-expression, using slowed-down film footage and close scrutiny of the facial muscles to detect deception and emotional nuance. He’s pointed out smiles that hide fear, conceal contempt, or mask pain—and demonstrated how easy they are to distinguish from an authentic, felt smile. A recent Brandeis University study found that older adults are better at making that distinction. After years of life experience, they know intuitively whether a smile is genuine or forced.
Others who’ve grown adept at reading smiles are people who’ve been through a breakup or lost a job, suggested a study published in the January 2010 Journal of Experimental Social Psychology. Simply by gauging the sincerity of people’s smiles, those groups proved better equipped to choose genuine allies in the workplace.
Yale University psychology professor Marianne LaFrance recently wrote a book that’s a mouthful: Lip Service: Smiles in Life, Death, Trust, Lies, Work, Memory, Sex, and Politics. She points out that a real smile involves the whole face; a fake smile uses only the mouth. A real smile appears easily and lasts only a few seconds; a fake smile “seems to snap on and is held too long.” Also, a real smile is symmetrical; when one side of the mouth curves more than the other, sarcasm and contempt enter the picture.
The Gender Divide
Women are better at reading smiles than men—and women smile more often than men. They even have larger smile muscles, which leads to a chicken-and-egg question: Do they smile more easily because their face lends itself to a smile, or are their muscles larger because they smile more? (The question’s moot if a woman injects enough Botox, because it can paralyze the muscles involved in real smiles.)
So why do men, especially those high in status, smile less? Perhaps because a smile can seem submissive. A woman’s smile is known to signal sexual interest, and it works: Men are most sexually attracted to women who look happy and least sexually attracted to women who look strong and confident, found a 2011 study at the University of British Columbia. Conversely, the women in the study were least attracted to smiling, happy men. They preferred a certain hauteur—strong and silent, arrogant and powerful, or dark and brooding. The logical explanation comes from evolutionary biology: Women want proud, high-status, dominant males who will be competent to provide for them and their offspring. And men don’t want strong, confident women who might challenge their dominance.
Speaking of evolution…we owe society to our smiles. “Earlier primates and mammals lacked the flexible facial muscles that allow smiles,” Cloninger says, “but the expressiveness of the faces of monkeys allowed them to function in large social groups.”
For the humans who followed, smiles became social glue. But now, Cloninger warns, technology’s stealing those smiles: “One of the things lost in much social media is the direct observation of moment-to-moment variation in facial expressions and eye contact.” Messaging and texts don’t give that richness—no matter how many emoticons you add. “The addition of video chat, however, is consistent with monkeys, chimps, and humans liking facial communication,” he notes, “and especially liking smiles as a sign of social approval and good humor.” Video chat allows us to add the nonverbal communication we’ve come to rely on; it feels more holistic. But it’s still not perfect: “Notice that videoconferencing has not replaced traveling to meet in person,” Cloninger says. Compared to live smiles and handshakes, “video is less effective, even in business.”
A 2010 study in Psychological Science indicated that people who grin broadly might wind up with crow’s feet, but they’ll live longer. And a study in the February 2011 Academy of Management Journal found a huge difference in the mood of bus drivers when they faked smiles and when, by thinking positive thoughts, they summoned real smiles. On days when the smiles were forced, the drivers’ moods deteriorated, and they tended to withdraw from work. On days when pleasant thoughts and memories made their smiles genuine, their overall moods improved and their productivity increased.
Why? Ekman and his colleagues have found that the Duchenne smile reaches parts of the brain associated with pleasure and happiness. A fake, mouth-only smile does not. If you learn how to fake a Duchenne smile, however, lifting your cheeks and crinkling the skin around your eyes, you can produce similar brain activity—improving not only your own mood, but also that of anyone in your company.
Smile, and the world smiles with you.
Engineers at the University of Missouri in Columbia have created a new tool called the “plasma brush” that could change the way dental fillings are treated—and possibly cut down on the need for costly tooth repairs. The brush, developed in collaboration with researchers at Nanova, uses plasma technology to quickly disinfect cavities for fillings. “We want to solve a common problem in dentistry,” explains associate professor of engineering Hao Li. The brush uses a flame to treat the surface of the tooth, so it’s more compatible with the filler and creates a longer-lasting bond between the tooth and the filling. Clinical trials are in development for this summer, and the brush could be
available to dentists by next year. —Todd Schuessler
Don’t floss? You’re not alone. Studies reveal that only 3 percent of the population flosses twice daily, according to South County dentist Dr. Dan Sindelar. People might change their habits, though, if they knew flossing could significantly reduce the risk of a heart attack. In his new book, Refresh Life, Sindelar describes some of the health problems that can stem from poor oral hygiene, including cardiovascular disease, stroke, and diabetes. Flossing can control the main oral offenders, bacteria and inflammation. But for one in three people, a genetic predisposition to “hyper-respond” to inflammation in the mouth can lead to other health problems. Sindelar recommends a simple rinse test to determine whether you’re genetically predisposed. —Todd Schuessler
REASONS TO SMILE
To address the lack of dental care available to some St. Louis children, Dr. Thomas Flavin helped to create Give Kids a Smile (636-397-6453, givekidsasmile.org), a nonprofit committed to “taking care of some of the kids that we knew were being underserved and marginalized,” he says. Area dentists and volunteers hold free bi-annual dental clinics at Saint Louis University’s Center for Advanced Dental Education to provide dental care for children whom area schools identify as at-risk. St. Louis–based Smile Squared (smilesquared.com) is also trying to better the smiles of those in need. It sells biodegradable/recyclable toothbrushes on a buy-one-give-one model at area stores and dentist’s offices. The company also sends toothbrushes out to those in need all over the globe. —Sarah George
Articles by Jeannette Cooperman, Sarah George, and Todd Schuessler