Would we still have lips? Maybe we'd gain a prenhensile tongue if we didn't. Im sure every adult can imagine ways that would be fun.

Let me introduce you to an old(giant) species of armored fish that was armed with shears for teeth: https://en.wikipedia.org/wiki/Dunkleosteus

The entire family of armored fish is the first known vertebrates to have true teeth as well as among the first fish to have jaws. (Previously being more like algae suckers and lamprey-esque).

It is thought that they went extinct from being slower and not much better armored than unarmored fish like sharks and ancestors of predatory bony fish.