Sometimes dialogue is overrated, and in fact sometimes its down right terrible. However, its the delivery of the actor/actress that breathes life into the words. On the other hand what happens when their are no words to hide behind? The entire delivery depends on the actor/actresses' emotion and physicality. Here is a great example of great actors/actresses acting sans dialogue. Enjoy.
http://www.nytimes.com/interactive/2010/12/12/magazine/14actors.html