I am on my 5th aligner and my front teeth are still crooked, one of my front teeth isn't moving forward, I noticed since my 3rd aligner the tooth in question doesn't sit right in the brace, it seems to fill with spit because there is a gap between the brace and my tooth! At the end of the wear time of each aligner I've noticed they are only loose one side but tight on the other side! My dentist has told me we will go back to aligner number 3 then on to 4 and then 5 again, is this normal?