1 year after losing my retainers, my teeth have shifted a lot. Would I be able to move them back with just retainers, or do I need to get braces? If I do have to get braces, would it be better to go with invisalign or traditional metal braces. My teeth are still relatively straight, so would the traditional metal braces work faster than invisalign? How long would each procedure take? Which one is typically more expensive?