Oh no!  What a bummer! The plants will probably come back if they have lower branches or at least from the roots but you may have to re-train a central leader  or a main trunk to the tree. 

You may want to help protect them further. Deer can reach up pretty far to get the new tender growth, as you now know. If you put a second fence or extend the fence out further, a few feet away from the trees in all direction, so they can't reach over or have the space to jump over, that may be helpful. You will probably want to put mulch or woodchips around the root flare and not touching the trunk of the trees to help keep down grass and weed growth in between the fences. 

Let us know if you have further questions. 

Emily