Barbara Pileggi sees her orthodontist appointments as a chance to offer a cautionary tale. She'll sit in the examination chair and call out to her peers - mostly children - in other chairs.

"Now kids, keep those retainers, or you're going to end up back in this chair like me when you're 40 years old!"

A fifth-grade teacher in Northeast Philadelphia, Pileggi knows. The 46-year-old got her braces off in October - for the third time.

Her first set was put on at 12, and she had them for four years. After they came off, she wore her retainer for a year and then threw it out. By 24, her teeth had shifted, so she got braces again before her wedding. That retainer also lasted a year. Eventually, she was complaining about her teeth again.

So two years ago, she went to Calvin Lee, an orthodontist with offices in Glenside and Doylestown, who was treating both her children. She got a family discount and the full tin grin.

Now she wears her retainer. (You should, for life.)

When adults get braces, people notice. Plus, celebrities such as Tom Cruise and Gwen Stefani have been photographed with brace faces. So adults who want to fix what didn't stick, as well as those who never wore braces as children, are going to orthodontists like never before. In 2008, there were more than 1 million people 18 and older in braces in the United States and Canada, up 24 percent from 1996, the previous year the survey was completed.

"I think 30 percent of the American population in braces is adults," says Monisha Iyer, a Harvard-trained orthodontist in Marlton. At her practice, 40 percent are grown-ups.

We may be an image-conscious society, but much of the growth in braces-wearing adults can be attributed to better oral health: We actually have more teeth than previous generations of adults. Decades ago, "it was standard that you had dentures when you were 40," says Pam Paladin, a spokeswoman for the American Association of Orthodontists.

But starting in the 1960s, she says, dental philosophy changed from extraction to prevention. Fluoridated toothpaste and water greatly helped prevent decay. And the medical community eventually realized that adult teeth could be moved successfully. That's why children of the late 20th century are today's adult orthodontia patients.

Mecca Baker, 33, of Marlton headed to the orthodontist when she was pregnant with twins. Although she had always had straight teeth, they started to separate slightly - the babies, her doctors said, were taking up a lot of calcium, leading her teeth to shift. They recommended braces to stop and reverse the movement.

So in May, Baker, a compliance officer for a defense contractor whose twins are now 15 months old, went for it. She chose the all-metal option - she likes her coffee and didn't want stained braces - and says it's been worth the slight pain.

"When they first adjust them, there's a little bit of discomfort," she says, "but for the most part, if you can experience giving birth, you can experience having your braces adjusted."

This is the sort of comparison orthodontists didn't hear much in the past from their clients, who until the previous decade were nearly all preteens and teens. Neither was a question Pileggi posed:

"Can alcoholic beverages inflame your gums?" she asked Samuel Meyrowitz, Lee's partner, during a recent office visit. "Because all of a sudden, I put my retainer in and it rubbed on my gums."

If you haven't been to an orthodontist in decades, a lot has changed. For one thing, braces are rarely tightened. Instead, stronger wires are generally put in each time. Bands are passé. Brackets are cemented to the front of each tooth.

There are many different materials, systems, and methods for straightening teeth, ranging from metal to ceramic, traditional braces to self-ligating systems that don't require rubber bands to tie the wire to the brackets. Less obtrusive options include behind-the-teeth lingual braces and the clear plastic, retainer-like trays of Invisalign.

There are gold brackets for people who want to treat their braces like jewelry.

Even the final look has changed.

"Just like fashion changes, so do aesthetics of the mouth," Iyer says. "Broader smiles, a more toothy show, more upper tooth showing when you speak: Those are all goals we try to meet. Whereas before, maybe the emphasis was more on straightening the teeth and making the teeth look good on stone models. And now it's more about making the face shine."

Make sure you shop around before choosing an orthodontist. "I would ask to see the results of the orthodontist, so that you know what their hand produces," Iyer says. "Because every orthodontist is different. Every orthodontist has different aesthetic goals, different follow-throughs."

Prices generally range from $3,000 to $10,000, depending on which type of braces you choose and where you live. Invisalign is more expensive than traditional braces. Some dental plans cover adults; many only cover children up to age 16. Flexible spending accounts can also help.

But there's no age limit on getting braces, says Iyer, who has patients in their 70s. You just need to more carefully consider overall oral health in adults - the status of the gums, any decay, crowns, or root canals - "so that we're not putting force on teeth in an inappropriate manner."

Adult teeth often move faster in people who had crowded mouths as children. And despite previous theories, orthodontists say, wisdom teeth are not to blame.

"The back teeth tend to drift forward as we get older," Lee says. "The front teeth have no place to go. It gets worse as you get older."

Marsha Fingles sure thought so. She had wanted braces her whole life.

"I had fangs," says Fingles, 51, of Bensalem, a nanny whose three children inherited her husband's naturally perfect teeth. "The eyeteeth stuck out. I didn't smile with my mouth open because I was embarrassed."

She thought the only solution was to have veneers, but she eventually discovered that braces could fix the problem.

When her orthodontist took the braces off, she cried. "For the first time in my life, I didn't mind smiling."

Chad Newton, 30, of West Oak Lane got ceramic braces last May. Everything is clear except a thin metal wire.

"People don't even know that I have them," he says. "Some of my friends who I haven't seen in a while say, 'You have braces?' 'I had them when you saw me the last two times.' "

But his students know. A seventh- and eighth-grade teacher for the Philadelphia School District, "I got a better connection with my students after I got the braces," he says.

"The kids love it," he says. "They'll give me a hard time about other stuff, but a whole bunch of them have braces, too."

Newton had wanted braces for a long time, but his parents couldn't afford them. So he decided to fix the imperfections when he could.

His first career after college was as a broadcast journalist at the CBS affiliate in Syracuse, N.Y. Invisalign was not yet readily available, and he couldn't wear braces on the air.

When he switched careers, though, he decided to go for it.

"I wanted to have that bright smile, that perfect smile."

Even though orthodontists see many adults these days, there are still reminders that children get braces in droves: colored elastic ligatures, rubber bands classified by animal names, bubblegum-flavored latex gloves.

Like Newton, most adults keep everything as unobtrusive as possible, but Pileggi embraced the full experience.

"I swear, when the Phillies won the World Series," she says, "it was because I had my red and blue rubber bands."

Contact writer Ellen Dunkel at