Oscar Wilde once said "a fashion is merely a form of ugliness so unbearable that we are compelled to alter it every six months".

One such alteration is happening as you read this, in London. For it is the time of fashion shows and new clothes, of trends for next spring and the newest hot thing.

Speaking of ugly, many in the fashion industry are heralding the perceived preference for models with a big gap between their front teeth. In New York, where last week the seasonal catwalk shows kicked off, the Wall Street Journal noticed and reported it, and the chatter became a roar. (These seemingly insignificant developments carry great importance when the right model can shift many thousands of wool-mix camel coats or "premium" jeans).

The trend for diastema seems to have started – this time around – with Lara Stone, pictured, the amazonian model wife of David Walliams, who is currently stalking about in ads for Calvin Klein.

Zeitgeist-spotters have been quick to co-opt fledgling model Georgia Jagger and actresses Anna Paquin and Elizabeth Moss to the trend, using the "more than three makes it legitimate" rule. Paquin's mouth, which in The Piano was kooky, has grown into something rather sensuous, which suits her current kinky vamp TV drama True Blood; Moss (Mad Men's Peggy) is that show's style crush for thinking women, with her more authentic sixties dentistry than her bleached and capped co-stars.

And therein lies the appeal of the gap tooth. It's a little sexy. Chaucer's bawdy Wife of Bath sported the look, a 14th century symbol of sensuality, and one only has to look at Brigitte Bardot, Lauren Hutton and Madonna during her "Sex" period to see its enduring appeal.

So current fashion embraces sex. It happens from time to time, usually after a few seasons of androgyny which makes clothes hang beautifully but which often leaves women feeling a bit, well, flat.

What's more apposite is the suggestion that the rise of the gappy smile is a reaction to the ubiquitous practice of retouching, which engenders unrealistic ideals of beauty. "It's a love of the imperfect, and the authentic," says Stefano Tonchi, editor of W magazine (which, it should be noted, regularly runs 20-page editorials of implausibly perfect models).

We inhabit an age in which retouching is so rife that last week the staggeringly beautiful Scarlett Johannson was claimed to have been retouched in a current ad campaign for Mango fashion chain. Anyone who saw the viral campaign for Dove in which the model had her eyes, skin, neck – well, everything – altered and improved, now looks at any photograph of a smooth-skinned, sparkling-eyed face with suspicion.

However, if it were true that women were rejecting perfection, might we see models with wrinkles, fillings and (whisper it) cellulite? No, the gap-tooth trend is a sanitised, symmetrical version of imperfection, promoted by the fashion industry itself. "Look, we can do 'normal'," it shouts.

Lara Stone and her gappy grin is no more normal than Kate Moss and her snaggle-toothed smile, or Erin O'Connor and her equine nose. These women are genetically advantaged; their quirks are more unique selling points than deal-breakers.

So place your bets now for next season's flawed fashion. My money's on the return of the mole; an "imperfection" first championed by Cindy Crawford.