Watch enough TikTok videos and you’re sure to see one extolling a special kind of do-it-yourself dentistry. Not about brushing and flossing, except maybe flossing with strands of your hair. These are videos on drilling into your teeth and cementing gems to them or filing your teeth to reshape them. People have been styling their teeth for centuries across the globe throughout North and South America, Africa, and Asia. But social media — particularly TikTok, where everything old and new is nip/tucked into short videos with trendy sounds and served up fresh to young eyes — has breathed life into…