Well I was told that I was advanced around 8mm from my first surgery, but the aesthetic changes appeared minimal. In fact, as the swelling went down, it became more apparent that I was hardly advanced. Note: this procedure was done with wires, not with a titanium plate.
I spoke to another surgeon around 3 months later and decided to proceed with a revision. He removed my wires and told me that there may have been a relapse.
Waited around 3 months in between surgeries, and am happy with results now. Initially, even after the revision, I felt I was a tad under projected, but as the swelling went down, I really started to appreciate my new appearance. If it helps, my chin was severely recessed prior to surgery, but 7mm was enough to produce an amazing improvement. Do you plan on having your plates removed and/or go in for a revision of any form?