Thank you!
And what is the max advancement can be achieved by the procedure in average? (in mm)
5-6 mm. 7-8 is possible, but much higher chance of relapse. I had 5-6mm. First surgeon I saw said 6 mm advancement, 4 mm setback. The second and third surgeon I saw said 6 mm advancement "but can't really tell until decompensated with braces". I settled on surgeon number 3.
3 months before surgery I saw another surgeon. I was almost completely decompensated. He said 7-8 mm, but maybe, maybe double surgery. In the end I had surgery by surgeon number 3.
Initially after surgery he said he moved me 7-8mm. When I saw him 5 weeks later he traced my postop X-ray over the preop one and said he moved me 5-6mm (1 mm more on the right because it was more recessed). I asked why the discrepancy. He said "when you're moving such a big block of bone it's hard to tell exactly how much you're moving". Who knows, maybe I had a like relapse as wel (i definitely had vertical relapse) - the bigger the advancement is required, the more they move extra to anticipate the inevitable relapse. They basically play this by the ear. IMO they just moved the jaws until the bite splint fits, make it a little bit extra in case of very big advancement and call it good.
1 year after surgery my bite is solid.