According to an article published in The Independent, dentists and researchers have come up with a formula for the perfect smile—including the size and width of each tooth; the curve, color, and shape of the teeth; and the overall width of the smile.

Patients who are pursuing a perfect smile are advised to hide their gums, hold back on the bleach, cover the bottom teeth, and set their lips at just the right angle.

"Everyone wants the perfect smile, and Jessica Simpson’s is the one we get asked to reproduce the most," said Nicholas Davis, DDS, MAGD, of the Loma Linda University School of Dentistry in Loma Linda, Calif. "Creating the ideal smile involves taking all kinds of dimensions and factors into consideration, including the shape and size of the face, the lips and gums, as well as the teeth.”

According to the report, the color of the teeth is important, and too many are bleached too white.

"One of the first things about a smile people notice is the color," said Davis. "People are bleaching their teeth, and many times they do it beyond what is natural. The teeth should be the same color as the whites of your eyes. If the teeth are too white, they become more dominant than the eyes."

There are strict mathematical ratios governing the ideal smile, according to Davis. Its width should be no less than half the width of the face at the same height and, for the best effect, both upper and lower lips need to be symmetrical on each side of the midline of the face. All of the visible teeth should be straight, with no visible signs of restoration work. The top teeth need to be dominant, with little seen of the bottom set. The laterals should be 61.8% the size of the bigger teeth. The next teeth along should be 61.8% of the laterals. The width of the central teeth should be 80% of the height, and the length should be around 1/16th of the facial height.

How long the central teeth should be varies, said Davis, but they are too long if they interfere with or impinge on the lower lip. The back teeth should diminish in size from front to back.

Gums are also important, Davis said, and to avoid a horsey smile, very little should be seen. Their color is critical and should be a healthy, pale pink.

[The Independent, November 25, 2007]