Plus, the history behind the tradition. A big milestone in any child's life is when they lose that first tooth. When that permanent larger tooth pushes out the baby tooth, it's like a rite of passage ...

For 20 years, Dr. Purva Merchant has been answering letters from gaptoothed children and their parents — roughly 6,000 in all. “Happy growing up,” she typically replies. Credit...Su Yun Song Supported ...

The letter looked like a ransom note, each jagged letter traced over and over for emphasis. The message got straight to the point: “I KNOW IT’S YOU MOM.” A fourth-grader named Caden had begun to ...