While bones can regrow themselves when they break, teeth aren’t so lucky, and that leads to millions of people worldwide suffering from some form of edentulism, a.k.a. toothlessness.Now, Japanese researchers are moving a promising, tooth-regrowing medicine into human trials—the first patients will be receiving the drug intravenously in September of this year. If the trial is successful, the researchers hope the drug will become available for all forms of toothlessness sometime around 2030. The a...