I haven't seen Dr. Gunson. But I will be getting a third opinon and he would be a good option to get that from. My upper lip is swollen and the braces are hitting the back of it. It looks much worse than it will in the future. I'll keep that in mind though. I don't know what my decompensated overjet is... Here is some info.
The info file is like I told you which is you DON'T have
recessed mandible. It says you have mild prognathic mandible (which is good).
It also says you are 'brachycephalic'. The brachycephalic skull is 'A' on the series. A common trait of that is the short chin. So, elongating the chin (and calling it a day and doing nothing more than that!) will bring you closer to the illusion of 'mesocephalic' of skull 'B'.
http://www.scielo.br/img/revistas/dpjo/v18n3/26f02.jpg