OK, it’s not as bad as it sounds. It’s not like the studio digitally removed a mustache or anything. Though, just like Henry Cavill in Justice League, it was the mouths of Leonard Nimoy and Eric Bana that required some movie magic. For Bana, it was the fact that Nero’s teeth were far more damaged than the actor’s. Now, you may want to roll your eyes at the idea of digitally replacing an actor’s mouth instead of just using, I don’t know, fake teeth? But to be fair, it was a common complaint from actors on several Star Trek television shows that it was difficult to act well with a bunch of plastic in your mouth.
When it comes to Nimoy, there was an error with the syncing between video and audio. Not a huge deal, so they called Nimoy in to do some re-recording of his lines. The filmmakers recorded Nimoy’s face so they could tweak his expressions to match the newly recorded lines if needed. They even went so far as to recreate the lighting conditions on Nimoy’s skin so that it would look as smooth as possible. However, they couldn’t quite light the lips right. The solution? Fully animated lips!