Problem With My Chin And Neck

Hi, good afternoon to all the network.

I have some questions about my chin, I am 23 years old, male, and I got a chin implant when I was 15, because the doctor told me that I have an underdeveloped low jaw, that was the reason I went to surgery. Everything have been, but now, I want another surgery because I can see that I have the chin skin all the way to my eden's apple, in an straight line, so my questions are: can I get another modern chin implantment? Or can I get a jaw augmentation? Or is better to have a liposuction? I heard that if I make liposuction in my neck, soon it will appear fat again, it's that true? I have an almost-twin brother, and he doesn't have that problem on his jaw, and he looks wow!, I want the same ;)

thanks for helping me