Invisalign would be a great option for you! It is a series of clear aligners that gradually move the teeth into the proper position. The teeth could be pushed in a bit, and what we call "overjet" corrected. The smile line could also be improved, evening out the lower "incisal" edges of your teeth so they are more symmetrical and balanced. Best of luck.
Shifting front teeth
You have two options. The first is Invisalign and the second is braces of some sort. Both will allow you to move your front teeth back into a more favorable position. One thing to think about is why the teeth shifted again? Are you wearing your retainer? Do you have a tongue thrust that is forcing the teeth out of position. It will be important for your long term stability to know why the teeth moved and how will you stop it from happening again.
You could have Invisalign clear aligners used as the technique to straighten your teeth. I would recommend trying to align more of the front teeth than just 2, and that could also help to level the incisal edges to a more favorable aesthetic.