onathan Liebesman's January 2003 film, Darkness Falls, depicts a small town in the terrifying grip of a sinister, possibly murderous Tooth Fairy. Graham Joyce's eponymous novel, The Tooth Fairy, is not much brighter, though arguably the fairy in question is more creepy than outright psychotic. Even Thomas Harris' Red Dragon (a 1981 novel that spawned two interestingly different movies) features a not-quite-human creature by that name who does nasty, inhuman things I won't discuss here.
Maybe it's a reflection of the times we live in, but you'd never know from these chilling stories that the "actual" Tooth Fairy is harmless, fair-minded and very, very small. The deal, in case for some reason you haven't heard it, is this: When a loose baby tooth finally falls out, it's placed under the kid's pillow at bedtime, and in the morning we find it's been spirited away and replaced with a dime or quarter, or these days, sometimes a dollar bill.
Owing to both the lateness of the hour and some presumed magical influence, the fairy is never observed during this process. However, in a plethora of stories and paintings, the creature is described as a winged female humanoid of remarkably small size—certainly smaller than a cat, and more likely about the size of a Norway rat—who is white or very pale of skin and dress, and carries a wand of some sort. What does she need all these teeth for? Rumors are divided on this point, but the most common answers are that they go into a kind of Tooth Museum or are used to construct an ever-growing Pearly Castle up in the clouds somewhere.
Now, as far back as Viking times, the people of Scandinavia have recognized a "tooth fee" to be paid as a gift when a child's first tooth appeared. Some sources state that a fee was also paid for shed baby teeth, which were then strung onto decorative necklaces. Be that as it may, the echoes of Celtic and Nordic tradition in the Tooth Fairy legend make it seem properly ancient and mysterious.
An origin story that's long in the tooth
In fact, though, the Tooth Fairy's origins are much more recent than that, and shrouded in mystery. She seems, for whatever reason, to have been a North American invention of the early or mid-20th century, arising not from a single book or story (as with the lumberjack giant Paul Bunyan), but as a sort of urban legend pieced together from multiple sources. My Merriam-Webster dictionary cites an improbable origin date of 1962, while other sources place it, more credibly, in or around 1900. Today, the Tooth Fairy visits the U.S. and Canada, with occasional cameo appearances in other English-speaking countries. Elsewhere in the world, she's known only by reputation.
But all of that may be about to change.
In April of this year, Sontango Shi of the National Institute of Dental Health (Bethesda, Md.) announced the discovery, in his own daughter's tooth (which was being washed at the time for collection by the Tooth Fairy), of a pulpy mass of living tissue which, upon microscopic examination, proved to contain juvenile stem cells.
You'd really have to be living under a rock this year to have missed hearing about stem cells, but in the interests of thoroughness I'll just say that these are the blank or unprogrammed cells that renew our bodies' tissues. In their embryonic form, stem cells can become anything—literally any cell type found anywhere in the body. Simply injecting them into the site of a heart or brain injury is often sufficient to promote the growth of new tissue which would otherwise be impossible. Their therapeutic potential—and dollar value—is enormous.
Sadly, though, only one source is known right now for embryonic human stem cells, and that's actual human embryos. This presents certain ethical quandaries which have hobbled research, despite the howls of outrage from sufferers of crippling diseases like Parkinson's. Scientists are focusing instead on a different sort of stem cell, the stromal cell, which is found in the bone marrow of adults. Unfortunately, these cells are not totipotent—they can differentiate into cardiac tissue, bone liver, and fat cells, but they can't change into anything we want them to be. They also grow more sluggishly than embryonic cells do, and probably have shorter telomeres, meaning they can't divide as many times (see "Does Dolly Have Old Age on the Lamb?").
But here's the good news from NIDH: These juvenile dental stem cells (now known as SHED cells, or Stem cells from Human Exfoliated Deciduous teeth) are found in all baby teeth, of which every human sheds exactly 20 before entering adulthood. And these SHED cells, while not totipotent either, proliferate much faster than stromal cells, and are capable of producing fat and bone cells as well as additional tissue types, including nerves. Thus, they could potentially be used to treat brain diseases like Parkinson's and Alzheimer's, and crippling bone problems like osteoporosis or very serious compound fractures. And probably for stuff like breast enlargement as well, yeah.
The whole tooth and nothing but the tooth
If these shed teeth are stored safely (frozen in liquid nitrogen, for example), then they might provide a rich source of stem cells for their previous owners 30 or 50 years down the road, with zero risk of rejection since the cells come, after all, from the patients' own bodies. And even if you haven't frozen your teeth (I know I haven't), there's still hope, in the from of ... you guessed it: the Tooth Fairy.
If she collects even one tooth from even 1 percent of the children in the U.S., she'll quickly accumulate a cell bank with millions of unique lineages. For stem cell recipients, this raises the chance of finding a compatible donor to, well, nearly 100 percent. If she then charged a thousand dollars per injection—a modest fee by today's medical standards—she'd find herself in command of an industry worth tens of billions of dollars annually. A pearly castle indeed!
So don't be fooled by this year's crop of fairy-phobic science fiction: the Tooth Fairy could well save your life someday, and maybe even your good looks. But wait, you say: She's just a fictional entity, like Batman or Zorro or World Peace. She doesn't really exist! And this, sadly, is a true statement. But all it really means is that the job is open to anyone that wants it, for the price of a Web site, a few gallons of liquid nitrogen, and—why be cheap?—a $500 scholarship to slip under every kid's pillow. Can you say ka-chinggggg?
Wil McCarthy is a rocket guidance engineer, robot designer, science-fiction author and occasional aquanaut. He has contributed to three interplanetary spacecraft, five communication and weather satellites, a line of landmine-clearing robots and some other "really cool stuff" he can't tell us about. His short writings have graced the pages of Analog, Asimov's, Wired, Nature and other major publications, and his book-length works include the New York Times notable Bloom, The Collapsium and most recently The Wellstone and a related nonfiction book, Hacking Matter.
