The classic debate, and sometimes an actual controversy, is whether chin augmentation is best done with an implant or by moving the chin bone. While patients and surgeons often try and compare them by their level of invasiveness, that is really an irrelevant and short-sighted thought process to that decision. That discussion more likely emanates from what the surgeon is capable of doing or what the patient may be willing to undergo that what may actually be dimensionally better for the chin deficiency problem.
There are, however, limits as to what either chin augmentation method can accomplish. The largest standard chin implants can provide no more than 11mms of horizontal projection, very little if any vertical increase (1 to 2mms) and variable amounts of width. (although custom chin implants can significantly exceed these amounts) Conversely a bony genioplasty offers different dimensional possibilities with horizontal increases up to 16mms (based on the patient’s thickness of bone), 10mms of vertical lengthening through a opening wedge but no real width change possibilities as an intact downfractured bone segment.
Blended chin augmentation is defined as when the dimensional changes needed exceed whatever is possible using standard performed chin implants or within the bony contact limits of a bony genioplasty. As a result blended chin augmentation combines an implant with a bony genioplasty to achieve a dimensional change that neither one alone can achieve.
While a bony genioplasty and a chin implant are typically perceived as completely independent procedures, there is no biologic reason they can not be combined if the patient’s dimensional needs so require. Having done many such combination chin surgeries it has not shown any increased risks of complications behind what either procedure alone has. The key is to make the bony genioplasty the workhorse of the procedure to keep the ‘implant load’ low on the tight soft tissues of the projected chin.
In a two stage blended chin augmentation, a chin implant is placed secondarily for added chin projection. This is really an ‘unintentional’ staged approach to combining the two chin procedures often recognized secondarily when the initial bony genioplasty turns out to be aesthetically a bit inadequate. Implants can be safely placed secondarily over a prior healed bony genioplasty.
Dr. Barry Eppley