Okay, a couple things come to mind.
First, there are people who can smile naturally with their mouths open, showing teeth. And then there are those of us who feel we look unnatural, if not downright scary and/or bizarre, with a toothy smile, regardless of our dental condition. I think my close-mouthed smile looks natural and is quite charming paired with my sparkling hazel eyes.
If you ask me to show teeth for a photo, the result, to me, is getting a little too close to Jack Nicholson's "Heeeeeeeere's Johnny!" scene in
The Shining (although I think I have better hair). Others may not think I look scary with a toothy smile, but that's how
I see myself in toothy pics.
Second, my parents started out as working class and built our family up to a solid middle class level, and we ALL went to the dentist at LEAST once a year...usually every six months. My teeth are pretty straight considering I never had braces, so except for a hereditary lower incisor thingy (No. 24 or so folds in) I've only had to put up with a LOT of fillings. The fillings were my fault, I ate a LOT of candy when I was younger, and I wasn't fanatical about brushing then.
Finally, at this point in my life, I brush my teeth three and sometimes four times a day. My teeth have always been a gleaming off-white. My dentist tells me I have "soft" teeth. They're prone to cracking and decay, take on the colors of caffienated drinks that encounter them, and would be abysmal if I didn't take care of them. She said that even with whiteners, my teeth will never be the glowing Hollywood kind unless I got caps, crowns or something. So, even though my teeth ARE in pretty good condition, I'm still a tad self-conscious about them because they'll never be pearly-white.
I've never been waved off because of my teeth, as far as I know, but just to let you other folks know that there are some of us who are not extravagant with toothy smiles for a reason!
Thrax