Hi, I've researched the questions on realself.com but couldn't find an answer. I completed my treatment 4 months ago and wear my retainers faithfully every night. However over the last few weeks I've noticed my teeth have become tender. Question: if I wear the retainers longer than usual (9 hours vs. 6 hours), will that cause tender, sensitive teeth? Are the retainers adjusting my teeth back from possible movement during the day? Thanks in advance for any response!