Can I Restore My Reduced Jaw Angles With Bone Grafts?

Q: Dr. Eppley, I had a jaw surgery for my lower jaw, a BSSO advancement of 10mm was done, however I was talked into having my gonial angle shaved by the surgeon as he said otherwise the jaw would look too broad. However, now my lower face looks too narrow, cheekbones appear wider, and the whole face is thrown out of balance.

I’ve seen a video of a surgeon here who used bone obtained from chin reduction to use it to increase the gonial angle, though he’s never posted the results. Should I consider this procedure for me? I’m afraid of bone resorption, but I also hope that since I need only 5 to 6mm of increase in my gonial angle it should be possible with grafting, I do not necessarily need any vertical advancement in the angle. 

I’ve attached my CT scan here, the front profile of the CT scan has no difference and the width of the jaw looks exactly similar, only in the side profile you can notice that the gonial angle was shaved off a bit. 

I anyways need a surgery for correcting my chin a bit, should I also give rib grafting a shot for the increase in gonial angle? Please guide me.

A: Onlay bone grafting to the jaw angles will likely undergo a high rate of resorption. Since the jaw angles are not functionally loaded (for example like a long bone) there is no stimulus for the bone to stay around. This concept has been known in craniofacial surgery, where onlay bone grafting originated for the face, for over three decades. In addition you would need to harvest the bone so you are correct in that a rib graft or cranial bone graft would be needed. You also have to think about how you are going to get a bone graft, shaped to fit the needed augmentation, and secured into place with a screw back into the hard to visualize recesses of the back of the jaw angle.

That being said, this does not mean it can not be done…just that you have to consider all these factors for a relatively small amount of jaw angle bone augmentation. It is one thing where a small bone graft is available anyway (the chin reduction you mentioned) and there is no need for a secondary harvest site, there is little to lose then by putting it somewhere else. But when you have to deliberately create a harvest site and the whole outcome of the surgery rests of what happens to it…this requires more careful preoperative thought.

Dr. Barry Eppley

Indianapolis, Indiana