A sliding genioplasty is a well known chin augmentation procedure whose effects at increasing the projection of the lower face are well known. By bringing the mandibular symphysis forward not only is the chin bone enhanced but the neck angle is improved with the skeletal lengthening of the jawline above it.
But there are other effects of this bony chin procedure, perhaps better described as ‘non-effects’, that are often less appreciated but aesthetically very important. One of these is the change in the depth of the labiomental fold. While the same phenomenon exists with chin implants, the deepening of the labiomental fold is un unavoidable sequelae of any type of chin augmentation. Because the anatomic location of the labiomental fold is a fixed point above the chin, and even though it does not change, the forward projection of the chin causes it to look deeper. In addition the lower lip above the labiomental fold also does not change with chin augmentation because its forward position is principally determined by the location and angulation of the lower teeth.
While there are no maneuvers to bring the lower lip forward during a sliding genioplasty chin augmentation, there are techniques to blunt the labiomental fold deepening effect caused by it. Filling in the bony step created by the sliding genioplasty can be helpful and has been done over the years by a variety of grafts and materials. I do not think what fills in the step is that important but in the properly selected patient the mere act of making some effort to do so is.
One method to fill in the bony step is to use a removed chin implant that is often encountered when doing a sliding genioplasty. About half of the sliding genioplastues that I perform are because of a prior dissatisfied chin implant procedure. The size and shape of most standard chin implants is a natural fit into the wide bony step offs caused by larger sliding genioplasties. There is some slight hesitation in placing an implant higher up closer to the depth of the intraoral vestibule and incisional closure but this is quelled by the fact that there will be mentalis muscle coverage over it.
While in sliding genioplasties that have no chin implant removed I would not reach for one to use to fill in the step off (I would prefer cadaveric bone particles or rib bone graft) recycling an existing chin implant is both logical and cost effective.
Dr. Barry Eppley
Indianapolis, Indiana