Diastema - flaunt it for those who got it

Struggling with a sense of alienation following the death of his father in 2008, fashion designer David Delfin asked an orthodontist to insert a bracket to open a space between his two front teeth.

"It was a metaphor for the separation I was feeling," said Mr. Delfin, who called his spring 2009 collection "Diastema," the medical term for a space between two teeth, usually in front.

Gaptoothed Celebrities Flaunt Their Smiles

It turns out Mr. Delfin was ahead of the fashion curve. At model casting calls for New York's fashion week, one of the most coveted attributes is an affront to modern orthodontics: gapped teeth.

The look is a bold departure from recent standards of idealized beauty that have rewarded curvaceous and perfect-smile models, such as Doutzen Kroes and Miranda Kerr, with high-profile ad campaigns.

Instead of perfection, designers now want what casting directors call "characters."

"I think people want to see something different, something off," says casting director Natalie Joos, who is selecting models for the runway shows of Lacoste and Cynthia Steffe this season.

Other distinguishing characteristics in demand this season include tattoos, piercings, scars and even albino coloring.

Some say the popularity of physical flaws reflects the skepticism of today's youth toward the air-brushed perfection of the digital age.

"It's a love for the imperfect, and the authentic," says Stefano Tonchi, editor-in-chief of W magazine. "These are values that are more and more important for younger generations. Originality, authenticity…in a world that is more and more digitally enhanced."

In editorial spreads in Vogue and W, as well as ads for high-end brands like Chanel and Marc Jacobs, gaptoothed gals are having a moment.

In a new ad for Hudson jeans, Mick Jagger's pillow-lipped, gaptoothed model daughter Georgia appears open-mouthed and topless, locked in an embrace with a tattooed man.

Miu Miu's fall ad campaign features a young model named Lindsey Wixson wearing a fur vest and flashing long, neatly spaced teeth.

Even Lauren Hutton, a supermodel in the '70s and '80s known for her signature gap, is getting more work these days: She was featured on the cover of the September issue of Condé Nast U.K.'s Love magazine.

The diastema is also gaining traction in Hollywood, as high-profile actors like Anna Paquin, of the vampire series "True Blood," and Elisabeth Moss, of "Mad Men," grace the red carpet with their pearly whites—and dark gaps.

In a recent issue of Us Weekly, Ms. Paquin said she considers it rude when people ask her why she hasn't "fixed" her smile.

The gap has long been celebrated in many African cultures as a sign of beauty. But in Europe and North America, gapped teeth weren't always considered chic.

According to the medieval laws of physiognomy—in which facial features were thought to dictate personality traits—a gap was a visual signal that a woman was "lustful and licentious," says Colin Jones, a professor at Queen Mary University of London who is writing a book about the history of dentistry.

In the 14th century, Geoffrey Chaucer wrote in his Canterbury Tales of the gaptoothed wife of Bath, who says, "as help me God, I was a lusty one/ And fair, and rich, and young, and well begone"—old English for "well-endowed."

In more recent times, amply spaced front teeth have graced the mouths of a wide range of celebrities, from David Letterman to Madonna. But they have never been a widespread trend cultivated by the fashion and entertainment industries.

Sotheby's is currently exhibiting a series of photographs of gaptoothed model Ms. Wixson. The series, called "I Remain, You Desire," follows Ms. Wixson, 16 years old, as she attended casting calls and prepared for runway shows last year.

"Lindsey is one of these girls saying, 'This is my face. This is who I am,'" says Gabrielle Revere, the photographer who followed her on her rounds. "People are responding to it, because it is unconventional."