Celebrity smiles revealed
There are four types of celebrity smiles that people can identify themselves with, it has been claimed.
Psychotherapist Emma Gold told toothpaste brand Aloe Dent that Katie Holmes, wife of Tom Cruise, often displays an obviously fake smile which is fixed and oblong-shaped.
However, those who have a broad, laughing smile like Lily Allen often make little or no eye contact but use around 80 face muscles at once, usually followed by laughter.
According to Ms Gold, Angelina Jolie has the "perfect dazzling beam" which is characterised by a wide, curving mouth and exposed upper teeth. The eyes often crease up and the eyebrows dip slightly.
"Genuine smiles are by far the most obvious as they are generated by the unconscious brain, so are automatic," she said. "When people feel pleasure, signals pass through the part of the brain that processes emotion."
The expert added that Madonna displays a toothy grin due to the gap at the front of her teeth, which in some cultures is thought to be a sign of a strong-sexual nature.
A Mintel survey for the British Academy of Cosmetic Dentistry found that two-thirds of people believe that people who have a warm and open smile are more approachable.
