Why do we need braces to straighten our teeth?

What were early dental braces like? Why are your teeth so crooked? How do braces work? For free home activities sign-up at www.WhoSmarted.com See omnystudio.com/listener for privacy information. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.