You ever wonder when they show a tribe from G-d knows where that had barely any contact with our civilization, how come they've got perfect white teeth and they've got them all? Nothing crooked, nothing missing.
It might be better to investigate these things based on the assumption that "G-d knows where" isn't a single place, and that all people that one considers primitive aren't the same people.
For example, you ever wonder when they show primitive people and their teeth are terrible, or when people that live in your culture spend no time on their teeth and never visit the dentist, but their teeth are fine?
Or how some people are naturally thin, and some have bone structures that seem like they were made to be fat?
Sadly, you will often see 40 year olds missing many teeth in those same areas.
Tough food, lot’s of chewing → No crooked teeth