Implants without exception cause erosion. Talking from experience. CT scan will most of the time show (both medpor + silicone cause erosion). If it doesn't instantly show up in the scan, a surgeon opening up should be able to see. (Implant -> permanent inflammation of tissues -> erosion).
The chin wing is interesting and I've seen several terrific results also years post-operative, that looked less fake than implants, but there are so many things not clear to me.
- Is the incision always intra-orally and along the complete border/below the gumline of the lower dental arch?
- I don't get the cut that is made. No matter what drawing I make and how I place the cut, if I'd like to have some more drop down in the jaw angle (that is now roughly 110 degrees, with a nice vertical ramus)/like to have a bit longer ramus, and a bit more forward projection in the chin without too much elongation of the chin (just a little bit), as a result
1) The lower part of the jaw angle/ramus moves forward when the chin wing is moved forward. As a result you get a 'step off' in the ramus.
2) If you want to change the tilt of the jawline a bit, and make it for example a bit less steep, when the chin wing is rotated, the lower part of the ramus would also tilt a bit backwards. You would never end up with a nice vertical ramus that way it seems to me. (The step off in the ramus aside). Unless the chin wing is kept in the same position/not rotated when it is moved forward, and the border of the lower mandible is shaved down in its entirety to make the jawline less steep: but is this even possible/done? That seems rigorous to me.
3) The step off in the ramus could be counteracted, if the chin wing is cut in some places. But then you will end up with step off's along the jawline. (which is what I don't like about a genioplasty).
You never can get a nice elongated vertical ramus without step off in the ramus it seems to me. Unless I'm just not looking into things correctly. Or unless, the hip bone graft is also used to build up a new ramus/jaw angle, but I haven't heard of that.
Yes, I had a chin implant before my jaw surgery and the x-ray showed SIGNIFICANT erosion to the bone. I have an early x-ray from that time if anyone wants to see it.
Implants are still common because the idea is the bone erosion will be (much) less than the actual gain from the implant. Also, the main erosion happens in the first 6 months or so. After that, it's apparently stable. So, it's not like the bone will continue to erode for the rest of your life.
About the chin wing - no, you are not looking into things correctly, as you put it yourself. You neglect the fact that they use a bone graft in the process.
In my case (and I think in 90% of the other cases), they took a HUGE bone graft from the hip. So, if you account for the bone graft into your equations, you'll realize that no, a step off is not typically a result of this surgery, and yes, you can lengthen your ramus considerably in the vertical direction.