Had chin implant, still feel I need a jaw implant, want a more square jawline/contour face, would like a second opinion?

 Thank you for your pictures. And my opinion, I would not recommend I drawl implant. You have very good definition to the angle of your jaw. You do have a deep mental sulcus. In my opinion, you probably have a natural weakness to your jaw that has been camouflaged by your chin implant.  More surgery is not your answer. 

Matisyahu, Be careful what you ask for; in my experience more is not always better! Your jaw line looks fine to me. Perhaps cheek implants. See a specialist but be conservative. Good luck!