Thanks for this information:
https://ibuzzing.medium.com/the-retention-phase-in-orthodontic-treatment-638c6aae62ff
https://www.bloglovin.com/@deepakgupta63/what-is-an-orthodontic-retainer
https://canvas.umn.edu/eportfolios/6596/Lifestyle/Why_Orthodontic_Retainers_Are_Important_After_Braces
https://iu.instructure.com/eportfolios/30895/Health/What_Are_Dental_Retainers_And_Why_Are_They_Necessary
https://ko-fi.com/post/Everything-That-You-Must-Know-About-Dental-Retaine-K3K64439U
https://whatmatters.site123.me/blog/what-are-the-benefits-of-using-dental-retainers
https://learnwordpress.uwm.edu/dailygeeks/fixed-vs-removable-dental-retainers/
https://canvas.yc.edu/eportfolios/4950/Health/The_Convenience_Of_Using_Retainers_After_Orthodontics
https://www.vingle.net/posts/3639800
https://www.open.edu/openlearncreate/mod/oublog/viewpost.php?post=2396
Cheers!