I mentioned the Matrix in my first post. This just goes to show that this happens more often than not to males, but my purpose for this thread was to focus on females. It really doesn't belong in any of the other forums.
I failed to mention it in my last post, but that Twisted Metal clip is exactly the sort of thing I'm thinking about. It's a shame it just cuts off after the event, and there were no scenes after the wish was granted. Chances are it was just a one-shot ending as well so I wouldn't expect to see her mouthless in future TM games if she's in them.
The realization, the freaking out over being mouthless is one of the best parts to me. It's why so many of the mouthless image edits don't do it justice, since there's rarely any expression of surprise in the images.
Another example I forgot to put in my first post was this scene from
a foreign tv show (the title appears to be Kakabakaba?). Unfortunately the girl this happens to is a little too young and unattractive, but the effect is just what I'm looking for. It's a bit cheesy with some obvious slowdown, but it works. Though I have no idea what's being said in the scenes.