How do I request a last size invisalign tray from my last treatment?

There should be no issue ordering the last aligner by your doctor. You can also try going back to some of the last trays you had during your treatment to see if that helps.

Your orthodontist should be able to order the last tray for you. I would contact your orthodontist so this can be done ASAP. I always recommend my patients to archive their aligners and not throw them away for this very reason. They can bring their aligners in, and we can recommend the aligner that they should begin. We have had a lot of success treating relapse cases this way for minimal fee to the patient. Good luck!

Your Orthodontist can order your last Invisalign tray for you and have it shipped express to your house. You can also wear the aligner before that to keep your teeth in place until you get that. 

Hi there,You should contact your treating dentist as soon as possible. They can order an additional tray and may want to make you some temporary retainers until it ships in. Your teeth will relapse very quickly without anything on them right now so you should address this quickly.Good luck!