Meat Eating Tiny Teeth Wearing Big Brained Primates

It turns out that all the primates with the genus homo share a common feature, as their brains increased in size, their teeth decreased. Of all the world's primates we are the only ones to see this development. Homo erectus, homo sapian, etc etc all see teeth decline with brain increase.

This is probably because, well, let them say it

"A change in diet, incorporating a higher amount of animal food, must have been one of the keys to this phenomenon. The quality leap in Homo's diet, through a greater intake in animal proteins, fats and certain olio-elements, is essential for a correct working and maintenance of the brain. On a similar note, a larger brain allows greater social and cultural development, which, at that time, led to the achievement of important technological innovations." Science Daily

Full article.

In short as we began using more tools and hunting with said tools our need for teeth changed, so somewhere along the line an ape was born with smaller teeth and it didn't mean his/her instant death via starvation…only instant death by everything else with teeth.

Go apes with clubs!