I am 60 years old and have been working on my mouth, jaw etc. for the past 12 years. Palate expansion, ALF and recently Invisalign. STILL not where I want to be and am determined now to really do mewing. Because of 8 teeth extracted when young (including wisdoms) and braces, my mouth is smaller than it should be and pushed back. At my age this is now contributing to a falling chin, jawline and neck.  I am currently determined to retry mewing but knowing how truly difficult it is to do properly and see results I am wondering if wearing my Invisalign retainer every night is just going to defeat the purpose?  On the other hand I don't want to see my teeth get crooked or relapse after all the time and money spent on palate expansion, ALF and Invisalign such as it was.  Answers to this seem confusion and contradictory, even from Mike Mew himself.    Any advice, ideas greatly appreciated.