Our Ancestors Didn’t Have Crooked Teeth

We know that in the history of mankind, rotten teeth came about because in the food abundance of the modern world we consume a lot more sugars and starches than our ancestors did. But what about crooked teeth? They weren't so common in ancient times. Did we evolve to have smaller jaws with no room for teeth to line up, much less wisdom teeth? It seems so, although animal studies have shown that eating soft foods vs. hard foods can affect jaw development regardless of genetic history. Now I'm wondering if switching diets make any difference in how crooked an adult human's teeth could be, or whether it's too late by then. What foods could we serve our children to encourage bigger jaws and straight teeth? Chewing gum? (via Digg)