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Smile! Scientists work out the secret to the perfect teeth
Last updated at 23:52pm on 25.11.07Aa formula for the perfect smile. dazzling white smile might be essential for Hollywood stars.
But those glow-in-the-dark teeth aren't right for most people, according to scientists who have worked out a formula for the perfect smile.
They took several factors into account, including the size and width of each tooth, the curve, colour and shape of the teeth and the overall width of the mouth.
As far as colour is concerned, they concluded that bright white should be avoided. Instead, they said, the whiteness of the teeth should match the whites of the eyes, otherwise the smile stands out too much and detracts from the rest of the face.
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Jessica Simpson: Many of those looking for a perfect smile want one like hers
"One of the first things about a smile people notice is the colour," said Dr Nicholas Davis, who led the research.
"People are bleaching their teeth and many times they do it beyond what is natural.
"The teeth should be the same colour as the whites of your eyes. If the teeth are too white, they become more dominant than the eyes"
Dr Davis, of Loma Linda University School of Dentistry in Southern California, said Jessica Simpson, who starred in the 2005 film The Dukes Of Hazzard, had most people's idea of the perfect smile.
"Jessica Simpson is the one we get asked to reproduce the most," said Dr Davis, whose study is published in the journal Dental Clinics of North America.
His formula boils down to a set of mathematical ratios. A smile's ideal width should be no less than half the width of the face and both upper and lower lips should be symmetrical each side of the mid-line of the face.
The top row of teeth should be dominant while very little should be seen of the bottom row. All teeth on display should be straight with no visible signs of restoration work.
The teeth should diminish in size from front to back. Those either side of the central teeth, the laterals, should be 61.8 per cent the size of the bigger teeth. The next teeth along should be 61.8 per cent of the laterals. The width of the central teeth should be 80 per cent of their height.
And to avoid a horsey smile, very little should be seen of the gums. London-based dentist Oliver Harman, whose clients include Catherine Zeta-Jones, said people should go for regular 'mouth manicures' to remove stains, but it was not necessary to iron out all imperfections with expensive cosmetic dentistry.
