You're asking about lower thirds and incisive bone.That's two different things, and the fix depends on what exactly you're trying to change. If it's mostly for looks (which I'm guessing it is), there are several ways to go, but none of them are one‑size‑fits‑all.
The incisive bone is that front part of your upper jaw where your front teeth sit. It matters because it pushes your upper lip forward. If that bone is flat or shrunken (common after losing teeth), your lip caves in and looks thin. If it's too prominent, you get that "overprojected" look. Both can be adjusted, but the route is totally different.
the actual options:
Chin work-genioplasty (cutting and moving the chin bone) or a chin implant. That fixes a weak or short chin, which is a huge part of the lower third
Bone grafting to the incisive area.if you've lost bone there, they can add artificial or your own bone to build it back up. This is usually done before placing implants, but it also improves lip support
Paranasal implants-these go next to your nose and fill out the upper jaw area, which lifts the lip and gives a more balanced profile
Fillers–temporary,but they can mimic bone support for a while. good for testing, but not a permanent fix.
Jaw surgery (orthognathic)-if your whole upper or lower jaw is off, they can reposition it. It's major, but some people do it purely for aesthetic reasons.
Braces/aligners – sometimes just moving the teeth can change how the bone and lips look, especially if your bite is messed up.
Here's the thing:nobody can tell you which one is right without seeing your face, your bite, and a 3D scan. The same "weak chin" could be a small chin bone, a recessed jaw, or even a deep bite-and each needs a different fix.
So if you're serious about this, go see a maxillofacial surgeon or a facial plastic surgeon who does both cosmetic and skeletal work. Get a CBCT scan and a side x-ray.They'll simulate what each procedure would do, and then you'll know exactly what's worth