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Can You Handle The Tooth? 10 Things You Didn't Know About Teeth

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The average adult has 28 to 32 teeth, depending on their "wise" set of third molars or lack thereof. But besides the importance of brushing and flossing, how well do you know your chompers? From LED braces to pearly whites in hard-to-reach places, we bring you the tooth, the whole tooth, and nothing but the tooth.

1. Some babies are born with teeth.

About one in every 2000 babies is born with natal teeth, so sometimes baby's first dentist appointment is only a few days after birth. Natal teeth usually grow on the bottom gums and tend to have weak roots; they're often removed to prevent problems with breastfeeding and accidental swallowing. Being born with teeth can be a symptom of certain medical conditions, and ancient physiognomy associated it with evil—but it's usually harmless. Advice columnist twin sisters Ann Landers and Abigail Van Buren were both born with teeth. So were Napoleon and Julius Caesar. 

2. Not everyone loses their baby teeth.

Losing baby teeth is a rite of passage, not to mention a small source of income for most kids. By age 3, the average child has a full set of 20 temporary teeth. These little chiclets loosen and eventually fall out as the permanent teeth below start to erupt. Children typically start losing teeth around 5 or 6 and finish in their early teens. But if a person doesn't have a replacement permanent tooth, that baby tooth will stay put.

3. And some people can't stop losing teeth!

Mo' molars, mo' problems? Depends who you ask. People with hyperdontia have extra, or super-numerary, teeth. Most of these teeth remain hidden below the gumline, but occasionally they'll erupt and crowd other teeth. If extra teeth crash a mouth party, a dentist can remove them, or an orthodontist can make bank straightening all of them out. Very rarely, a person will lose a "permanent" set of teeth at an older age, only to have a no-for-real-now set grow back in. The rest of us have to get dentures.

4. And you might as well do something with those teeth, right?

Image via Scrap&Smith's Etsy Store

What exactly is the Tooth Fairy supposed to do with the teeth she collects? If she's crafty, she might want to look into selling human tooth art on Etsy. Yep, there's apparently a small—and more than a little creepy—demand for artsy molars and incisors. Exhibit A: These double rings made of molars. Exhibit B: This quirky pendant that, dare we say, looks really cute. But these molar cuff links? Designer imposters. Even actress Scarlett Johansson made a golden necklace out of one of her extracted wisdom teeth and gave it to her ex-husband Ryan Reynolds. Do you think she got it back after they split?

5. Tumors can grow teeth, too.

No one wants to deal with an abnormal growth, but teratomas are especially icky. The germ cell tumors can contain several types of tissues and are usually found in the ovaries, testes, and near the tailbone. Some of them even contain teeth. And hair. And occasionally eyes, hands, and other limbs! Fortunately, many teratomas are benign and can be surgically removed. If you've got one, here's hoping the Tooth Fairy sends you a get well card.

6. But a tooth in your eye doesn't have to be a bad thing.

Ever hear the expression "I'd give my eye-teeth"? One woman literally gave her eye a tooth to restore her vision. In 2000, Sharon Thornton lost her vision to Stevens-Johnson syndrome, a condition that destroys the cells on the eye’s surface. Nine years later, the 60-year-old woman elected to try an unusual surgery. One of her canines was removed, so her cheek and dental tissue could be implanted in her left eye, replacing the damaged cornea. Within a day, the blind woman had regained 20/70 vision and the hope of improved sight in the future.

7. Braces are cooler than ever before.

Back in ye olde days of orthodontia, the most creative thing the metal-mouthed could do with their braces was choose rubber band color. Today's options include Invisalign or lingual braces hidden along the inside of your teeth. Or you can modernize traditional braces with glow-in-the-dark or LED technology. In the former option, fluorescent rubber bands or brackets glow when light-activated. (Orthodontists suggest shining a flashlight on the braces for a quick demonstration.) The Japanese clothing store Laforet Harajuku invented LED braces for a January 2011 ad campaign. Switched on by smiling wide, these multicolored flashing lights don't actually straighten teeth. They will, however, make you the coolest kid at a rave.

8. But not all cultures consider straight teeth the beauty ideal.

Straight white teeth might seem universally appealing, but one country's snaggletooth is another country's sex appeal. (How do you think Austin Powers got so much action?) In Japan, crooked teeth called yaeba are so coveted that some women with perfect teeth get crooked veneers to enhance their smiles. They figure that crowded chompers make them look younger and more adorable, which makes sense. American parents could save lots of money if the trend catches on here...

9. Humans will evolve past wisdom teeth.

A third set of molars helped our larger-jawed ancestors grind up roots, nuts, and leaves. But nowadays, 35% of people are born without wisdom teeth. Most of the rest of us are encouraged to get ours removed—our mouths are too small; our dentistry to pricey to screw up. When our bodies no longer need an organ or part, it becomes vestigial and eventually disappears. According to scientists, future generations will lack appendices, wisdom teeth, and maybe even little toes.

10. Candy's better for your teeth than raisins.

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Halloween's coming up, so pay attention: Not all sweets are equally bad for your teeth. In fact, you might be surprised which treats are more likely to cause cavities. Sugar from all the foods we eat feeds bacteria that create acid and erode tooth enamel. With enough erosion over time, a tooth becomes the Grand Cavity Canyon. So how do you have your snacks and keep the teeth to eat them, too? Ditch foods that get stuck in your teeth (breads, chips, and fruit snacks) for those that dissolve quickly (chocolate, caramels, and jelly beans). It's also better to snack all at once than to munch and feed bacteria throughout the day. Happy trick or treating!

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Essential Science
What Is a Scientific Theory?
Dean Mouhtaropoulos/Getty Images
Dean Mouhtaropoulos/Getty Images

In casual conversation, people often use the word theory to mean "hunch" or "guess": If you see the same man riding the northbound bus every morning, you might theorize that he has a job in the north end of the city; if you forget to put the bread in the breadbox and discover chunks have been taken out of it the next morning, you might theorize that you have mice in your kitchen.

In science, a theory is a stronger assertion. Typically, it's a claim about the relationship between various facts; a way of providing a concise explanation for what's been observed. The American Museum of Natural History puts it this way: "A theory is a well-substantiated explanation of an aspect of the natural world that can incorporate laws, hypotheses and facts."

For example, Newton's theory of gravity—also known as his law of universal gravitation—says that every object, anywhere in the universe, responds to the force of gravity in the same way. Observational data from the Moon's motion around the Earth, the motion of Jupiter's moons around Jupiter, and the downward fall of a dropped hammer are all consistent with Newton's theory. So Newton's theory provides a concise way of summarizing what we know about the motion of these objects—indeed, of any object responding to the force of gravity.

A scientific theory "organizes experience," James Robert Brown, a philosopher of science at the University of Toronto, tells Mental Floss. "It puts it into some kind of systematic form."


A theory's ability to account for already known facts lays a solid foundation for its acceptance. Let's take a closer look at Newton's theory of gravity as an example.

In the late 17th century, the planets were known to move in elliptical orbits around the Sun, but no one had a clear idea of why the orbits had to be shaped like ellipses. Similarly, the movement of falling objects had been well understood since the work of Galileo a half-century earlier; the Italian scientist had worked out a mathematical formula that describes how the speed of a falling object increases over time. Newton's great breakthrough was to tie all of this together. According to legend, his moment of insight came as he gazed upon a falling apple in his native Lincolnshire.

In Newton's theory, every object is attracted to every other object with a force that’s proportional to the masses of the objects, but inversely proportional to the square of the distance between them. This is known as an “inverse square” law. For example, if the distance between the Sun and the Earth were doubled, the gravitational attraction between the Earth and the Sun would be cut to one-quarter of its current strength. Newton, using his theories and a bit of calculus, was able to show that the gravitational force between the Sun and the planets as they move through space meant that orbits had to be elliptical.

Newton's theory is powerful because it explains so much: the falling apple, the motion of the Moon around the Earth, and the motion of all of the planets—and even comets—around the Sun. All of it now made sense.


A theory gains even more support if it predicts new, observable phenomena. The English astronomer Edmond Halley used Newton's theory of gravity to calculate the orbit of the comet that now bears his name. Taking into account the gravitational pull of the Sun, Jupiter, and Saturn, in 1705, he predicted that the comet, which had last been seen in 1682, would return in 1758. Sure enough, it did, reappearing in December of that year. (Unfortunately, Halley didn't live to see it; he died in 1742.) The predicted return of Halley's Comet, Brown says, was "a spectacular triumph" of Newton's theory.

In the early 20th century, Newton's theory of gravity would itself be superseded—as physicists put it—by Einstein's, known as general relativity. (Where Newton envisioned gravity as a force acting between objects, Einstein described gravity as the result of a curving or warping of space itself.) General relativity was able to explain certain phenomena that Newton's theory couldn't account for, such as an anomaly in the orbit of Mercury, which slowly rotates—the technical term for this is "precession"—so that while each loop the planet takes around the Sun is an ellipse, over the years Mercury traces out a spiral path similar to one you may have made as a kid on a Spirograph.

Significantly, Einstein’s theory also made predictions that differed from Newton's. One was the idea that gravity can bend starlight, which was spectacularly confirmed during a solar eclipse in 1919 (and made Einstein an overnight celebrity). Nearly 100 years later, in 2016, the discovery of gravitational waves confirmed yet another prediction. In the century between, at least eight predictions of Einstein's theory have been confirmed.


And yet physicists believe that Einstein's theory will one day give way to a new, more complete theory. It already seems to conflict with quantum mechanics, the theory that provides our best description of the subatomic world. The way the two theories describe the world is very different. General relativity describes the universe as containing particles with definite positions and speeds, moving about in response to gravitational fields that permeate all of space. Quantum mechanics, in contrast, yields only the probability that each particle will be found in some particular location at some particular time.

What would a "unified theory of physics"—one that combines quantum mechanics and Einstein's theory of gravity—look like? Presumably it would combine the explanatory power of both theories, allowing scientists to make sense of both the very large and the very small in the universe.


Let's shift from physics to biology for a moment. It is precisely because of its vast explanatory power that biologists hold Darwin's theory of evolution—which allows scientists to make sense of data from genetics, physiology, biochemistry, paleontology, biogeography, and many other fields—in such high esteem. As the biologist Theodosius Dobzhansky put it in an influential essay in 1973, "Nothing in biology makes sense except in the light of evolution."

Interestingly, the word evolution can be used to refer to both a theory and a fact—something Darwin himself realized. "Darwin, when he was talking about evolution, distinguished between the fact of evolution and the theory of evolution," Brown says. "The fact of evolution was that species had, in fact, evolved [i.e. changed over time]—and he had all sorts of evidence for this. The theory of evolution is an attempt to explain this evolutionary process." The explanation that Darwin eventually came up with was the idea of natural selection—roughly, the idea that an organism's offspring will vary, and that those offspring with more favorable traits will be more likely to survive, thus passing those traits on to the next generation.


Many theories are rock-solid: Scientists have just as much confidence in the theories of relativity, quantum mechanics, evolution, plate tectonics, and thermodynamics as they do in the statement that the Earth revolves around the Sun.

Other theories, closer to the cutting-edge of current research, are more tentative, like string theory (the idea that everything in the universe is made up of tiny, vibrating strings or loops of pure energy) or the various multiverse theories (the idea that our entire universe is just one of many). String theory and multiverse theories remain controversial because of the lack of direct experimental evidence for them, and some critics claim that multiverse theories aren't even testable in principle. They argue that there's no conceivable experiment that one could perform that would reveal the existence of these other universes.

Sometimes more than one theory is put forward to explain observations of natural phenomena; these theories might be said to "compete," with scientists judging which one provides the best explanation for the observations.

"That's how it should ideally work," Brown says. "You put forward your theory, I put forward my theory; we accumulate a lot of evidence. Eventually, one of our theories might prove to obviously be better than the other, over some period of time. At that point, the losing theory sort of falls away. And the winning theory will probably fight battles in the future."

This Just In
Yes, Parents Do Play Favorites—And Often Love Their Youngest Kid Best

If you have brothers or sisters, there was probably a point in your youth when you spent significant time bickering over—or at least privately obsessing over—whom Mom and Dad loved best. Was it the oldest sibling? The baby of the family? The seemingly forgotten middle kid?

As much as we'd like to believe that parents love all of their children equally, some parents do, apparently, love their youngest best, according to The Independent. A recent survey from the parenting website Mumsnet and its sister site, the grandparent-focused Gransnet, found that favoritism affects both parents and grandparents.

Out of 1185 parents and 1111 grandparents, 23 percent of parents and 42 percent of grandparents admitted to have a favorite out of their children or grandchildren. For parents, that tended to be the youngest—56 percent of those parents with a favorite said they preferred the baby of the family. Almost 40 percent of the grandparents with a favorite, meanwhile, preferred the oldest. Despite these numbers, half of the respondents thought having a favorite among their children and grandchildren is "awful," and the majority think it's damaging for that child's siblings.

Now, this isn't to say that youngest children experience blatant favoritism across all families. This wasn't a scientific study, and with only a few thousand users, the number of people with favorites is actually not as high as it might seem—23 percent is only around 272 parents, for instance. But other studies with a bit more scientific rigor have indicated that parents do usually have favorites among their children. In one study, 70 percent of fathers and 74 percent of mothers admitted to showing favoritism in their parenting. "Parents need to know that favoritism is normal," psychologist Ellen Weber Libby, who specializes in family dynamics, told The Wall Street Journal in 2017.

But youngest kids don't always feel the most loved. A 2005 study found that oldest children tended to feel like the preferred ones, and youngest children felt like their parents were biased toward their older siblings. Another study released in 2017 found that when youngest kids did feel like there was preferential treatment in their family, their relationships with their parents were more greatly affected than their older siblings, either for better (if they sensed they were the favorite) or for worse (if they sensed their siblings were). Feeling like the favorite or the lesser sibling didn't tend to affect older siblings' relationships with their parents.

However, the author of that study, Brigham Young University professor Alex Jensen, noted in a press release at the time that whether or not favoritism affects children tends to depend on how that favoritism is shown. "When parents are more loving and they're more supportive and consistent with all of the kids, the favoritism tends to not matter as much," he said, advising that “you need to treat them fairly, but not equally.” Sadly for those who don't feel like the golden child, a different study in 2016 suggests that there's not much you can do about it—mothers, at least, rarely change which child they favor most, even over the course of a lifetime.

[h/t The Independent]


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