Mysteries of the Universe: #7576TG6

So one of my guy's-guy friends called me recently with an unusual observation -- at least for him: He'd tuned into the royal wedding and noted something peculiar: "Hats," he said. "Really, cool hats. Man, those Brit ladies can do hats. They make the Kentucky Derby hats look downright dowdy."

And then, he added: "So, if they can do hats so well, why can't they figure out the teeth thing?"

"???"

"Their teeth," he explained. "They really are horrible, all gray and crooked. If they worry so much about their hats, then why not their teeth? I just think it's really weird."

It made me think how we Americans are so consumed with acquiring the perfect smile. First, the introduction of orthodontics in the 70s ... and, most recently, this obsession with getting our teeth as white as copier paper. We've perfected teeth, boobs, eyebrows, etc. Where do we go next?

I, for one, like a little gravity on a lady. And I'm a little wary of those with smiles that look computer-generated.

What makes teeth gray, anyway?