Louise Élisabeth Vigée Le Brun

Louise Élisabeth Vigée Le Brun's smiling self-portrait.
Louise Élisabeth Vigée Le Brun / Wikimedia Commons

A white-toothed smile is a gesture that many likely engage in dozens of times a day without thought. Historian Colin Jones traced the history of the smile and found a toothy smile is a relatively young phenomenon. 

In his recent book, "The Smile Revolution In Eighteenth Century Paris," he argues that the white-tooth smile emerged in 18th century Paris in conjunction with the cult of sensibility and the creation of modern dentistry.