Thanks for the replies.
I have a few points that I would like to clear up if possible.
1) When I smile my teeth actually show quite perfectly, upper and lower. I don't know if that is due to the way my incisors protrude out or what but yes.
2) With regards to the short lower 1/3, flat OP etc. I have seen a similar case to what I think you guys were describing here:
https://www.drantipov.com/cases/corrective-jaw-surgery/oms000025/. You can see the flat OP and MPA. In a video about this man Dr Antipov also showed that he could not smile properly. Without the rotation my ceph looks pretty similar to his ceph except my lower incisors stick out eliminating the overbite. It's pretty hard for me to tell exactly however I think I have over-rotated my ceph in the attachment but only slightly whilst my original is still highly under-rotated. I have viewed myself in multiple videos and in the mirror quite comprehensively and
I am 90% sure my MPA is between 17-24 degrees. Regardless, you can see here that they moved his upper jaw forward and down, big forward movement of the mandible with some CW rotation it appears and a big CCW genio. So from this I believe I require advancement with still little change in MPA but there is lee-way.
An extra point about this, weird thing about the guy's ceph, it doesn't seem to be along the frankfurt plane either.
3) GJ has suggested a 3 piece lefort for widening the upper jaw. I still really do not understand why widening of the upper jaw is required if the bite it perfect as it is currently. It is true that my palates are narrow and overall the entire jaw is small both in forward extension and width, but if you widen the upper jaw and the lower jaw is only advanced via bsso/genio wouldn't that make it impossible to correct the bite?
I really do not understand this. It is a major concern for me because I think one of the first steps for me is widening of the upper jaw via SARME, lefort etc. But if they widen the upper and the lower cannot be widened then thats fked...again IMDO seems to be the only thing that widens mandibles.
4) GJ you commented this would be quite high risk. I kind of got the feeling of this myself as I have seen quite a number of cephs now and mine is pretty dissimilar to most people. It seems that the most common overbite issue relates to too high MPA requiring CCW rotation. One thing that I have heard as passing remarks is that if the person's jaw is more delicate or smaller, risks are usually increased as it is more challenging to operate on a smaller jaw. Is this something that you guys have heard?..or is it bs.
5)
Downgrafting. Kavan, do you still recommend downgrafting if I do not have trouble smiling etc? When I smile right now I see the slightest bit of gum above my upper teeth. Keep in mind if I do get my upper palate expanded it's likely that my front teeth will move back with braces to reduce the protrusion, idk that could be changing things with my smile. I have seen cases where the lower and upper jaw is recessed (basically my case) and they cannot smile however they do not have such a high incisor protrusion as I do. Perhaps that is the reason that I can still smile because of how forward the teeth are... Furthermore after reviewing myself more closely and the ceph, making the MPA steeper with maxilla movement to match is actually not what is required I think...However in saying this, I think you are still going to be correct. The movement I require for my lower jaw would be quite dramatic and not really changing the MPA, OP much so the upper would have to match with similar movement. Both jaws recessed, both advanced requiring bone grafting.