Invisalign Retainer; Is it normal to use a patients last Invisalign tray as a mold for a retainer?

If you are 100% happy with your final result, then it is normal procedure to order your vivera retainers from this aligner, without either new impressions or scans

Thank you for your question.  As a top1% Invisalign provider, it is completely normal to order the retainer off the last aligner.  The retainers are usually tighter because they are a little thicker, they have to last longer then a regular aligner would.   Don't worry your dentist is following protocol. Your teeth should have been perfect with the last aligner and that is the mold used to hold them. I hope this helps 

This is not normal. It should be the exact same fit as your last tray.You should be rescanned/impressed.