I used braces as a teenager
Thankfully I never had them, but my daughter does now.  Her teeth are very misaligned, so they'll help straighten them out 
They help to arrange teeth 
They're also used to correct underbites, over bites, open bites, deep bites, cross bites, and malocclusions
That is true
There is evidence of Hippocrates and Aristotle trying to figure out ways to make braces around 400-300BCE
Really? That is a long history of dental braces
Archaeologists have found mummies with metal bands wrapped around their teeth