I have only had my appliance for a couple of months and have not yet done another sleep study. I plan to do the sleep study shortly.... So far I have had one day that I slept for 10 hours... It was wonderful.
If your nose is stuffy, nasal saline or using a Neti-pot along with Breathe Right nasal dilator strips may help. You may still have persistent obstructive sleep apnea, since apneas force up stomach juices into the throat. Did you ever get a sleep study done with your oral appliance in place?