3 Years Post Nose Job my Dog Bit my Nose, is the Little Hard Bump Under the Bite Permanent?

First things first. An animal bite mst be viewed and treated as an injection of animal saliva not your tissues. Proper antibiotics must be started immedately to prevent a serious nfection. Depending on the extent of the injury, the edges may need to be surgically cleaned and wond washed. The induration you describe could be an infection and or local inflammation in response to the bite. You would do well to see a Plastc surgeon. 

Just 3 days after a dog bite to your nose the bump may be secondary to bleeding, bruising, inflammation, or infection. You should be evaluated by or surgeon or physician.