Cut dry stems of Dendobrium or not?

[Ana Rodrigues]

Hello orchid experts! My mother got a beautiful white Dendobrium for Christmas, but it seems like it didn't respond well to the change of environment (nursery to store to house). We treated it just as the other sucessful Phaleanopsis she already had in terms of water, fertilizer and light. But all the stems/stalks (hope I'm saying it right) are withering and all the leafs are falling. One of the stems has a sprout at the base. So my questions are: Is this normal? What are we missing? And if the old stems die and get completely dry, should I cut them off?
Thanks in advance!