I am strangely obsessed with teeth. At parties I used to look at eyes — now I beam in on the jaws of my fellow guests. Usually I’m astounded at how many people are still walking around with teeth that overlap, that are crooked, that are too yellow or that sport obvious gaps.

If ever I’m home on a Thursday night, I am to be found transfixed by the Ten Years Younger programme on Channel 4, in which a succession of slightly depressed-looking women are transformed from drab and dowdy lumps to sleek and shiny go-getters. They are given everything from complete facelifts and tummy tucks to microdermabrasion, Botox, new wardrobes, make-up and hairdos — but of the whole box of tricks , the single thing that makes most difference in peeling away the years is having their teeth fixed. The change in their appearance usually reduces them to tears.

Admittedly, most of the guinea pigs have simply terrible teeth. Until I watched the programme I had no idea that in 21st century Britain there are people who simply never brush their teeth. And not only that — there are people who walk around with huge gaps in their gums, with hideous pointy sticks instead of proper, pearly teeth. There are people whose teeth are so bad that they are afraid to go out and never dare to smile.

Rather less disturbing are those whose teeth are basically in good condition but who would look better if those teeth were more even or a better colour. Today, these things can be fixed in a trice.

The snag is that cosmetic dentistry doesn’t come cheap. But these days the techniques are there to give everybody who wants one (and can pay for it) a million-dollar smile. Dentists offering the treatments are opening fancy salons on almost every high street in the land. The old austere and rather grim surgeries are being replaced by posh clinics with fancy names, offering all sorts of additional blandishments such as aromatherapy, a touch of stimulating massage or a little reflexology.

In part, it is programmes such as Ten Years Younger (and, of course, the dazzling smiles of Hollywood stars) that are responsible for the boom in cosmetic dentistry, allied to the growing number of market-savvy dentists who are not afraid to tell the public what they have to offer.

According to Dr Joe Oliver, of the Welbeck Clinic in Central London, the reason why the British took so long to discover cosmetic dentistry was simply that few people knew what it could do. Most British dentists took the view that all that mattered was whether teeth were healthy; looking pretty was a question of luck.

The British Academy of Cosmetic Dentistry (BACD) was founded only in 2003, but in America it is reckoned that “aesthetic procedures” are now the fastest-growing area of dentistry, with industry analysts predicting that by 2008 some $7.9 billion (£4.4 billion) a year will be spent on them.

And there are now signs that the UK is catching up fast. We spent £100 million on cosmetic dentistry in 2002, according to Market & Business Development, a market research firm. The group estimates that spending will rise this year to £360 million.

Cosmetic treatments range from traditional braces to the modern advances of porcelain veneers and tooth-coloured fillings.

James Goolnik, a spokesman for the BACD, says that demand for cosmetic treatments has more than tripled in the past three years. His practice alone has seen an 81 per cent rise in demand. “People look at the teeth of their favourite stars in films or in Hello! magazine and think ‘I want that’,” he says.

Dr Mervyn Druian, of the London Centre for Cosmetic Dentistry, receives patients from all over the UK. “Five years ago my practice saw one cosmetic case a month,” he says. “Now we see four a week.”

What many people may not realise is how quickly teeth can be transformed. Take teeth-whitening. Most — but not quite all — teeth can be done. If they are darkish yellow because of too many antibiotics or are genetically dark they won’t respond very well. If they are just a bit yellow through age, too much coffee or nicotine, though, they can be brightened up a lot.