I don't know, but I have always heard about pruning juniper, that if you cut too far into the hardened wood near the center, it will not regrow and you will be left with a hole in that spot:
"Junipers, however, have a so-called "dead zone" in the center of the plant where no new branches and stems are formed. If you cut within this dead zone, the plant won't be able to recover, and you'll be left with a patchy, misshapen shrub."
That would seem to apply to your shrubs. If the deer only munched the needles off the ends of branches, they should be all right. If they munched down in to the center, hardened wood, that area will not recover.