George Washington had wooden ones, held together by a spring, which is said to be why he looks so tight-lipped in his portrait on the dollar bill. Queen Elizabeth I had to take hers out before eating, and a 19th-century editor of the Church Times once set his alight when he fell asleep with a cigar in his mouth. False teeth have always been problematic. Given their ubiquity, the wonder is that you hear so little about them.

More than 16 million people in the United Kingdom wear full or partial dentures - almost 40 per cent of the adult population. A quarter of these are between 20 and 44, and about six million are "edentulous" - meaning toothless. Nowadays, dentists prefer to repair teeth, but there was a time when extraction seemed the simplest (and cheapest) way of dealing with decay. According to the British Dental Association, by 1968, 30 per cent of the adult population had no natural teeth at all.

But toothlessness has not always led automatically to false teeth. It was the National Health Service, in 1948, that made dentures available to everyone; before then, only the well-off could afford them.

Nevertheless, false teeth have a long and bloody history, starting with the Etruscans, who made the earliest surviving specimens in the seventh century BC. The first English book on dentistry, published in 1685, recommended transplanting animal teeth into human jaws, but better still were human ones, supplied by grave robbers. The Napoleonic wars were a fruitful source: for years afterwards, so-called "Waterloo teeth" turned up, collected from the battlefields by tooth dealers.

A book called The Strange Story of False Teeth, by John Woodforde, includes a picture of a set of 14th-century dentures dug up in Switzerland. Astonishingly, they were purely cosmetic: their wearers would have slipped them out before a meal, perhaps replacing them with an alternative device, called a masticator, which looked like a nutcracker and crushed food to a pulp. Even when the Wedgwood company started making porcelain teeth in the early 19th century, the results must have been grisly: two china half-moons painted to look like teeth.

Dentures have come a long way since then. Not only are they expected to look natural, but you should be able to eat with them too. Dentists take elaborate measurements; laboratories produce made-to-measure resin plates and set into them ready-made acrylic teeth which they choose from illustrated catalogues. If you get them from the NHS, a full set will cost you pounds 86. If you get them privately, you can easily spend several thousand pounds.

The gruesome thing about false teeth at the top end of the market - as featured, for example, in the catalogue from Ivoclar-Vivadent - a Liechtenstein company that manufactures dozens of different types of teeth in 20 shades and endless combinations - is not that they don't look realistic, but that they do. These glistening, high-performance pink-and-white grimaces are the Olympic athletes of the oral world. Their superior smiles are unanswerable: the small majority of us who are walking round with all our own teeth would undoubtedly look better if we traded them in for a set of acrylics