Earl, I've read a ton about Dr. Weston's research. A few books by doctors etc. who claim to be Weston Price advocates etc..
Here's what I've ascertained. Price, who did a study of societies such as the Massai tribe and other indigenous people living on traditional diets found a very low instance of dental decay in these groups. This is a fact. It's processed sugar, and especially processed carbohydrates that lead to dental carries. He also noted better arch formation and jaw formation in these people. Okay, now as others mentioned, pre-natal health etc. counts for a lot here. Even in India where the village he studied was vegetarian, they were eating wheat that had been specially harvested from mineral rich soil, was prepared by first soaking and roasting it etc. to rid it of various gut leaking properties (gut health is very important to the Price ethos), etc..
Now evolutionarily it is true that the human jaw has been getting smaller, and whether this parallels the move from pre-agrarian to post-agrarian diets is not completely conclusive, but even one generation CAN make a difference as epigeneticists are now demonstrating to us. I've been to a remote village in both Africa and India where people were relatively isolated and had been for centuries and were eating traditional diets and their dental health and facial formation was one the whole superior to what you'd find in a western city. That said, I think it's already a bit too late once you've had the kid, the nutrition needs to star pre-natally, and probably have been there for a few generations so that it has really influenced the genes. Also, you'd need to eliminate all processed foods to truly test this experiment.
Again, I agree, there are male models who grew up eating s**t, though they probably have tons of cavities and stuff --but again there are genetic freaks who have certain PH balances to their saliva that aggressively prevent cavities no matter way.
For general dental health I think the Weston Price protocol is the best diet: bone broth, no processed foods, no sugar, all natural and naturally prepared foods. Nothing out of a box or a package. But it's not gonna change the shape of your jaw. It will however probably resist you from developing all sorts of other diseases as well as keep your teeth strong and your gums healthy.