(KMSP) - MINNEAPOLIS (AP) -- Researchers at the University of Minnesota went to the Minnesota State Fair to discover what makes the perfect smile.
Sofia Lyford-Pike a facial plastic and reconstructive surgeon and assistant professor at the university went to the 2015 Minnesota State Fair to see what the average person finds appealing in a smile.
Lyford-Pike works on patients with paralyzed faces and routinely makes decisions about how to change their smile.
Stephen Guy is a faculty member in the university's Department of Computer Science and Engineering. He said more than 800 participants rated computer-generated smiles based on how pleasant, genuine and effective they were.
Researchers adjusted the smiles' width, the angle and the amount of teeth shown. The smiles that were in the middle for all characteristics performed the best.
Participants found that low angle smiles work better with little teeth showing while high angles smiles work better with a lot of teeth showing, Guy said.
"There's not just one good smile, there's a range of different combinations of things that make smiles good," Guy said.
The study also looked at people's perceptions of smiles in motion. The study found a small time difference between the sides of a smile forming was preferable to a perfectly synched smile.
"We expect a little bit of asymmetry to make the characteristic more human . it's more human to be imperfect," Lyford-Pike said.
Lyford-Pike said the data will help her choose the right surgical techniques to use on a patient. It can also help patients learn the best way to smile to reflect what they're feeling and help train those with facial weaknesses, she said.