I lost my retainer 2-3 months ago, so I haven't worn it since. I had my braces off 9 years ago. My two front teeth either moved outward and/or my two second teeth moved in. Would I need braces to make my teeth straight again? If so, would the cost be less since my teeth don't need a lot of work? Or would a new retainer fix this? I also want to fix my underbite. Would braces be able to fix this without a surgery?