The sliding genioplasty is the bony chin augmentation method that has a very long surgical history. In the traditional method it is an angled bone cut from the middle of the chin backwards going below the mental nerve and ending at the inferior border. This creates a down fractured bone segment that can be moved forward and/or upwards/downwards to be secured into the desired position.
But like any aesthetic procedure, and all forms of chin augmentation are the same, the patient’s aesthetic satisfaction with the result is never guaranteed…no matter how much preoperative thought was put into the surgical plan. While the sister chin operation, an implant, can be relatively easily modified or reversed, what about the sliding genioplasty operation? Little information is available about whether sliding genioplasty reversals can be done and how they are done.
Like all aesthetic operations when to do a revision should await until the full result can be seen. For the chin this is a minimum of 6 weeks and more ideally 3 months. Some patients may feel stressed to do it sooner, and I would not deny them if they are really possessed to do so, but how the chin may look at 3 weeks can change significantly by 3 months. Some patients may feel the need to get it reversed as soon as possible based on the premise that once the bone heals it can never be changed…but that is not true.
Sliding genioplasty reversal surgery is virtually identical from a bone cut standpoint as the original surgery. The indwelling titanium hardware can usually be removed. (I have not seen a case where I couldn’t do it although bicortical screw fixation can be hardest to remove) The bone cut has to be made through the original osteotomy line which is usually very evident. The original osteotomy line will be well healed with bone unless one is undertaking reversal in the first few weeks after surgery. As would/should be expected the thickness of this secondary bone cut is going to be thinner than the original bone cut….unless the forward movement was small. (5mms or less) In major sliding genioplasty movements (10mm or more) there is only going to be one bony cortex to cut through as opposed to the original two bone cortexes.
Once the bone is recut how easily does it move back and by how much should it be moved. The desired amount of reversal is an aesthetic choice with the majority of patients choosing a subtotal vs total removal. Since there was a reason the surgery was originally done this accounts for why most patients don’t want to go all the way back. And most patients aren’t going to go through the surgery for a millimeter or two reduction in projection. Therefore the typical setback is 50% of the original movement. In larger sliding genioplasty movements a complete reversal may not be possible due to soft tissue restrictions.
Interestingly of all the sliding genioplasty reversals I have done I have yet to have a request for a decrease in the amount of vertical lengthening done. This may be that pure vertical chin lengthening cases are far fewer than those done for pure horizontal movements. It may also be that many cases of vertical chin lengthening are smaller in magnitude as surgeons tend to be less bold in that directional change.
Dr. Barry Eppley
World-Renowned Plastic Surgeon