How safe are custom jaw line/chin implants?

It is safe when done by a good plastic surgeon. The surgeon has to take care of a few things like nerves, making good size pocket and putting the implant in the right place and avoiding any chances of infection.

Would recommend that you schedule a consultation appointment with a board certified plastic surgeon to discuss custom jaw line/chin implants.  The surgeon can answer all your questions and recommend the best strategy for achieving the outcome you want.  The three types of silicone jaw implants (Silastic, Goretex-like, and Acrylic/'Porex) are known to be safe. From a 3D CT scan, facial implants can be computer designed and manufactured in any size and shape. The final facial implant is created using a 3D printer.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA

All facial implants are safe no matter their size or shape. But they also share the same risks of infection and aesthetic issues of size and placement. In regards to custom jawline implants they are not necessarily safer than standard chin and jaw angle implants. What they do have is a lower risk of asymmetry and malposition since they are one implant while standard implants must use three implants to come close to the same effect.