I live in the UK, it's a procedure which you don't see a lot other than in Korea because it's usually to fix very severe bimax protrusion which they have a lot of over there and also it requires a surgeon who's extremely skilled and as done it plenty of times as there are more risks than normal jaw surgery.
I got it done by Dr Zarrinbal in Berlin, who's very skilled at procedures of the face. I'm going back to him in a couple months to get a couple more procedures done, so I trust him completely as I've had no issues since my surgery and all the numbness has gone now. Touch wood it continues to stay good