Here's some added related news about why so many have bad teeth....
"Diet and Teeth
Tool-use no doubt helped early humans in butchering their dinners. But there is evidence that the advance to cooking and using knives and forks is leading to crooked teeth and facial dwarfing in humans.
Today it's relatively rare for someone to have perfectly straight teeth (without having been to the orthodontist). Our wisdom teeth don't have room to fit in the jaw and sometimes don't form at all, and the propensity to develop gum disease is on the increase.
"Virtually any mammalian jaw in the wild that you look at will be a perfect occlusion—a very nice Hollywood-style dentition," said Peter Lucas, the author of
Dental Functional Morphology and a visiting professor at George Washington University in Washington, D.C. "But when it comes to humans, the ideal occlusion [the way teeth fit together] is virtually never seen. It's really the only body part that regularly needs attention and surgery."
Lucas argues that the mechanical process of chewing, combined with the physical properties of foods in the diet, will drive tooth, jaw, and body size, particularly in human evolution.
Essentially, by cooking our food, thereby making it softer, we no longer need teeth big enough to chow down on really tough particles. By using knives and forks to cut food into smaller pieces, we no longer need a large enough jaw to cram in big hunks of food.
"We're evolving to eat mush," said Bernard Wood, a paleoanthropologist at George Washington University."
The source:
http://news.nationalgeographic.com/news/2005/02/0218_050218_human_diet_2.html