A chin implant typically rests upon the lower aspect of the front part of jawbone and there are designs that can extend variably to the sides. These can be sutured to the periosteum or covering of the bone. Since they basically just sit above the bone in a precise pocket, they should not interfere with the mechanics of the TMJ. I often ask patients about TMJ or the efficiency of their bite because a chin implant won’t worsen, but also won’t improve TMJ. It really is just a cosmetic/nonfunctional change. There are other procedures that change the way your teeth come together and these would likely make changes in the TMJ. They are usually performed by oral maxillary facial surgeons. All my best!