In advance of last month's Chicago Midwinter Dental Meeting, the Chicago Dental Society asked 300 dentists which presidential candidate has the best smile. On the Democratic side, Barack Obama and John Edwards finished in a virtual dead heat, with 38% and 36% of the vote, respectively. Among Republicans, Mitt Romney was the runaway winner with 45%, while presumptive nominee John McCain pulled a mere 6%.

Granted, this is not scientifically verifiable data, but it did make me wonder about what message various smiles send.

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Obama, for example, has a wide, straight, white smile, which gives his face a youthful openness. His smile seems to cascade across his face in the same way that Julia Roberts' does. Edwards and Hillary Clinton, by contrast, appear to have narrower smiles that are, to use a technical term, a little crooked here and there.

As I am writing this, Obama is leading the Democratic field and gathering momentum, in part because of a personal magnetism that pundits cannot explain in precise terms. I would argue that a good percentage of that allure comes from a smile that says, "I am an open book. What you see is what you get. You can trust me."

On the other side of the aisle, McCain is not much of a smiler, perhaps because he has a visible gold crown on the right and a big ol' gap on the left. But clearly, this smile has spoken to people as well. To me it has said, like McCain himself, "I am not perfect, but I have been through tough times and come out ahead. I am battle-scarred but will continue the fight." Romney, who won the smile caucus if not much else, has a big, wide grin more akin to Obama's, but in my book his smile is undermined by maxillary central incisors that are much longer than their neighboring teeth—not to the point that he looks like Bugs Bunny, but to the point where he appears to have a Wall of Teeth behind which something may be hiding. How much shorter his maxillary central incisors would have to be for him to win the nomination is subject to further study.

Any thoughts on smile psychology or other orthodontic topics? Please write and let me know.

Christopher Piehler