Ten Year Olds and Teeth

I just got back from the orthodontist w/ my ten year old. I have 18 months left of being this man's byatch. She's brushing and flossing well, so I didn't have to get all bent about her brushing skills. I do wonder this- my teeth are perfectly straight, and her dad's are pretty much straight, all w/out braces, so where did the need for all this metal come from?