Well, you've already had done to the chin what would be considered a 'compensation' surgery for some recession to the lower jaw. That is to say IF you instead had had a bimax surgery, the BSSO could have brought the chin forward ( simply because the chin advances with the forward displacement of the lower jaw) and you would not have had to compensate for the lower jaw recession with the extent isolated chin work you got prior. So, at this stage of the game, IF you opted for bimax, they would probably have to UNDO what was done to the chin. So, if the bite is fine AND you are OK with your chin as it is now and ALSO if it's the narrowness from front view that you don't like, the most likely solution is custom jaw implants aimed to widen bigonial distance and perhaps also to 'drop down' the border of the posterior jaw.
As to suggestion of bimax surgery, that's would be good suggestion with a 'virgin' face as in BEFORE you got the chin surgery to COMPENSATE for lower jaw recession. But at this point in time, you would probably have to UNDO what was done to the chin just to have it. So, the conservative choice at THIS point in TIME would most likely be in favor of custom jaw implants aimed at blending in what was already done to the chin.
