One of the other moments of dramatic irony in act 4 is when Juliet tells her father in scene 2 that she will forever more be ruled by him and do what he says. This is dramatic irony because the audience knows she plans on faking her death to run away, but Capulet doesn't. His happiness and excitement to go forward with the wedding builds up the act before becoming dramatic again.
The next example is when Juliet's family discovers her dead in scene 4. The audience knows that she has taken the potion to just appear dead, but this scene gives a lot of drama because the audience gets to see how her family reacts and that they actually do care about her (especially her father).
