Large teeth tend to splay out if the upper jaw is "smaller". This results in the lower teeth achieving a crooked alignment.
Best bet is to restrict breeding to those with larger upper jaws.
Prognathism is no guide to jaw size though ~ just to its position vis a vis the skull.
Here's Winston Churchill's denture:
While a student he went to Lapland to run around, eat the food, live the life for something like 6 months! It's worth reading about his health and that of his father to make you wonder if he/they weren't suffering from being forced to eat a Western diet rather than the high iron reindeer and seal for which they might have been designed.
Linnaeus did the same thing on a grant ~ went to Lapland to study plants and animals.
I think you asked if there were any figures on Sa'ami native intelligence ~ depends on who you count as a Sa'ami. Can't find the diminutive Norwegian Sa'ami in Churchill's woodpile, but I suspect he's there ~ his brand of heart trouble with repeated "attacks" is fairly typical of what you can find among those who inherited one of the genes for Scandinavian porphyria. His father's health problems are certainly typical.