A new fashion has women paying to have their straight teeth disarranged. Unlike Western countries, Japan has never looked down on “yaeba,” or a snaggletooth, instead finding a less-than-perfect smile cute and endearing. “Yaeba teeth” have become more and more trendy in Japan recently. If this term is new to you, in Japanese, the word yaeba means ‘double tooth’, and it describes the fang-y, pushed-out incisors look that usually results from bunched or crowded teeth. So why have misaligned...