Will PEEK Jaw implants move/wobble decades later?

While there is a lifelong remodeling of the bones in our face, this shouldn't have any consequences relative to the implants. There will be some early pressure from the implants on the jaw, but it is minimal especially when they are custom. In part it depends on how much augmentation you are going for, but as long as they are not oversized relative to what your soft tissues can accommodate, it shouldn't be an issue. Any implant can fail, and that is the hard part about facial implants. The good thing is that angle implants are covered by thick muscles which will protect the implant. Chin implants are more at risk of failure given the proximity to the bacteria in the mouth. If the implants had to come out at some point, most people maintain about 50% of the augmentation so its not all lost. Just make sure that your surgeon knows the limits of the implants relative to what you are going for in augmentation.

There would be no substantive bony loss that would ever result in the implants having mobility. In addition in the long term screw fixation has no value in implant stability. It is the encapsulation process that locks the implants into place vey securely. The role of screw fixation is to hold the implants into the desired position on the bone until that fully occurs. (a few months after surgery)