I had braces for about 2 years when I was younger, (now in my twenties) but my teeth have shifted due to failure on my part in not wearing my retainer consistently. An orthodontist I spoke to recommended extracting 4 teeth (2 upper, 2 lower) in a process that would take ≈ 2 years. I really do not want to repeat the entire procedure again just to push back two teeth. Are there any other options to re-align them? Could installing braces only on my upper row work? Thank-you so much.