Losing teeth

The tooth that was threatening to leave a little red trail down Saskia's flower girl dress last month finally fell out. By the end it was dangling by a fibre, and it took a lot of convincing to get her to tug on it. 

I've never paid that much attention to six-year-olds losing teeth before, but it strikes me as a strange phenomenon. It seems arbitrary that teeth and not other body parts behave this way. What if the femurs were resorbed at age five, and half the kindergarten class were on crutches, waiting for the new bone to be laid down?

I'm starting to warm to Saskia's new grin. At least the gaps are an interim state, with a raison d'etre. Unlike her sister's: