Turn that frown upside down has taken on a whole new meaning in South Korea, with a plastic surgery trend that puts a permanent smile on patients' faces.
'Smile surgery' - or 'valentine anguloplasty' - has seen a surge in popularity among women in their 20s and 30s in the capital Seoul.
According to the Wall Street Journal, surgeons carrying out the procedures are defending it.
They say that patients see it as a necessary antidote to glum facial expressions - known as bitchy resting face to you and I - that are having a psychological impact on patients and is particularly popular among people in service industry such as flight attendants.
“Even when you are looking like your normal self, people keep asking you: ‘Why are you frowning?’” said Kwon Taek-keun, who has been working as a plastic surgeon for the past 20 years and is credited for first popularising the procedure. “That’s a lot of stress.”
It isn't the first time we've reported on the extreme lengths that women will go to in South Korea to be beautiful.
Earlier this year we saw women undergoing double-jaw surgery and spoon massage in a bid to get the perfect body.
Korean photographer Ji Yeo recently documented how Eastern and Western cultures have begun approaching plastic surgery differently.
Her series, entitled "Beauty Recovery Room" shows the painful lengths women will go to achieve their perfect body in South Korea.
Photographer Yeo captures painful post-op moments of Korean women
According to The Huffington Post US, Yeo was shocked how casual plastic surgery was for her female subjects, who offered the women post-op care in exchange for a portrait.
"It seemed to provide them pleasure and satisfaction. During the photo shoots, and even though they were in extreme pain, I could feel their excitement; the excitement of hopes realized."
Tell us what you think of Yeo's series of portraits in the comments below.