His majesty King Jigme Khesar Namgyel Wangchuck (L), 31, smiles at his bride during the purification marriage ceremony to Queen Jetsun Pema, 21, in the historical Punakha Dzong on October 13, 2011 in Punakha, Bhutan. The Dzong is the same venue that hosted the King's historic coronation ceremony in 2008. The Oxford-educated king is popular in the country and the ceremony will be followed by celebration in the capital and countryside. (Photo by Paula Bronstein/Getty Images)

First year cadets of the Military University of Communication smile before an oath-taking ceremony in St.Petersburg September 6, 2014. Some 700 first year cadets of the academy attended the ceremony before starting their studies. (Photo by Alexander Demianchuk/Reuters)

A woman smiles as she gets a new tattoo during Rio Tattoo Week in Rio de Janeiro, Brazil, Friday, January 16, 2015. Tattoo artists from Brazil and around the world gathered for the annual three day convention. (Photo by Silvia Izquierdo/AP Photo)

“Early morning in Mandawa, rural Rajasthan: it was the morning of Diwali and the streets were swept by smiling women in brightly coloured sarees as I took an early morning cup of chai. Celebrations started later, when darkness fell”. (Photo by Hamish Scott-Brown/Guardian Witness)

Catherine, Duchess of Cambridge smiles as she is saluted to during the Irish Guards Medal Parade at the Victoria Barracks on June 25, 2011 in Windsor, England. The Duchess of Cambridge and Duke of Cambridge are at the barracks to present service medals to members of the Irish Guards. (Photo by Chris Jackson/Getty Images)

A Maasai woman smiles as Camilla, Duchess of Cornwall is presented with a traditional Maasai necklace as Prince Charles, Prince of Wales looks on during a visit to Majengo Maasai Boma on November 9, 2011 in Arusha, Tanzania. (Photo by Chris Jackson/Getty Images)

Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

Claire McGuire (C) smiles after winning the women's snowboard division of the Bikini & Board Shorts Downhill at Crystal Mountain, a ski resort near Enumclaw, Washington April 19, 2014. Skiers and snowboarders competed for a chance to win one of four season's passes. (Photo by David Ryder/Reuters)