permanent retainers and mewing

[mtn_dude_193]

i had braces a year ago (no extractions) to fix my overbite and crowding and it did it really bringed my mandible more forward but after it finished they put those fixated retainers on both jaws 6 on top and 4 on bottom will this make mewing not work

 

[slimester]

will this make mewing not work

how could mewing not work masai jumps too