Q: Dr. Eppley, I had a chin advancement by osteotomy last year but I am not happy with the result. My chin is still too short. I would like you to perform another chin osteotomy for further advancement. I still prefer the chin osteotomy because of its permanent result. I have attached some pictures for you to review. How much further do you think you can bring out my chin?
A: Thank you for sending your pictures. I can see by your side view photo that you still do not have optimal horizontal projection as you know. The key question in determining how much more horizontal advancement can be done with an osteotomy needs to be determined through a lateral cephalometric x-ray. The sliding genioplasty is based on the principle that as the lower chin bone segment moves forward, its back end or cortical segment maintains contact with the front edge or cortex of the attached upper chin segment. Some bone contact must remain between the two bone segments for it to survive and not resorb. It may be entirely possible that your chin was moved as far forward as the bone would permit. (unlikely) The real question in my mind is how much further can the chin bone be moved. That is where the value of the x-ray is so important. If it can only be moved 2 or 3mms further forward, an osteotomy approach may not be worth it. (I suspect it can be moved at least 5mms but I need to be sure) The x-ray will also show what type of bone fixation was used so there are no surprises during surgery. One would not want to run across some method of fixation that is very hard or impossible to fully remove and allow the bone to be mobilized. (e.g., lag screw fixation)
The x-ray ultimately needed is a simple lateral cephalometric or facial film view. That can be gotten at any orthodontist and most oral surgery offices.
Dr. Barry Eppley