I think most people have braces for around 2 years, I had mine for just under that. It varies though, I've known people who've had them for 6 months, and others who've had them for 5 years! The time you have to wear your retainers also varies. I'm not sure about other people, but I personally have to wear mine for the rest of my life (if I stop wearing them, my teeth will move back to where they were originally, or there abouts)