Does A Sliding Genioplasty Always Male The Chin Shorter As It Comes Forward?
Q: Dr. Eppley, I am interested in a sliding genioplasty procedure. Since the sliding genioplasty is usually done through a diagonal cut as I have seen on the internet, I am interested in knowing if every horizontal advancement always has some degree of vertical shortening? Is it possible to advance the chin just horizontally without changing the vertical dimension? If so, how does the cut look then? I am scared that the side effect of advancing the chin forward might be some vertical reduction.
Thank you very much for your time.
A:In answer to your insightful sliding genioplasty question, control of the vertical dimension of the chin is affected by the following:
1) Even if not change is done to the vertical dimension with a sliding genioplasty it will usually look a bit longer as it is advanced due to the changes in the overlying soft tissue chin pad. (this is similarly true with implants)
2) The risk of vertical shortening is sliding genioplasty is related to the bone fixation method used. With a diagonal bone cut, if wire fixation or bicortical screws are used (neither of which I use) then vertical shortening can happen as these are bone compression techniques. And by definition almost always happens) If plate fixation is used the vertical dimension is controlled much better because there remains a bone cap with the advanced chin bone segment as the plate allows the chin bone movement due to be done in any horizontal or vertical dimension. (in essence it is a bone suspension method
As you can see this is a geometric function of the bone fixation method used.
Dr. Barry Eppley