Background: Chin augmentation is typically perceived as a horizontal deficiency. Conversely jaw angle augmentation is most frequently seen as a width deficiency. While these lower jaw corner deficiencies are certainly true for some patients, this is a limited perception of what are otherwise three dimensional structures. Undoubtably this is due to the historic implant styles that are used to augment the chin and the jaw angles.
But contemporary facial implant designs are often custom made in which there are no such dimensional limitations. Custom facial implant designs are typically done to create augmentation changes that are otherwise unobtainable from standard implant styles and sizes…which also means they can achieve shape changes that are more three-dimensional. This is classically illustrated in the custom wrap around jaw line implant which by definition changes the horizontal, vertical and width measurements of the lower jaw in various amounts.
One dimensional change that only a custom jawline implant can achieve is vertically lengthening of the entire lower jaw. This is one of the most frequently underdiagnosed changes to the lower face despite the well known facial third assessments. This is most likely because of an unfamiliarity of how to do so.
Case Study: This male presented for lower jaw augmentation for a more defined jawline. In looking at his facial proportions he acknowledged that he felt his lower facial third was vertically short. As a result a jawline implant as designed to vertically lengthen the inferior border of the jawline from angle to angle.
In such designs the question is always how much vertical lengthening is needed. It is one jawline dimension that is so unfamiliar it is easy to over estimate how much is really needed. While every patient can be a little different, a good rule of thumb is in 5mm range. This creates a more significant effect that one would think. Some designs are only vertically lengthened to eliminate a prominent antegonial notch to create a smooth and linear lower jawline border. One also has to factor in at the chin area how much horizontal augmentation is being done to not exceed the rule of ’12’.
When placing a jawline implant that has some vertical lengthening this means that the height of the jaw angle is by far the tallest/largest part of the implant. Being able to safely pass it under the mental nerve is not going to happen as a single piece implant. Thus a three piece placement technique is used where the implant is split into two jaw angle pieces and an elongated chin section. I prefer a geometric split technique placed just in front of the jaw angle part before it becomes too vertically high.
This then allows the chin segment to be placed through the submental incision and the jaw angles to be reunited with it through a posterior vestibular incisional approach.
Case Highlights:
1) A total jawline implant is a 3-dimensional technique for changing all of the dimensions of the anterolateral lower jaw borders.
2) When vertical lengthening of the jawline is needed consideration needs to be given as to how much the overlying soft tissues can stretch, particularly in the chin area.
3) Dissection for the primary vertical lengthening jawline implant must elevate all soft tissues attachments from the inferior border all the way around the lower jaw.
Dr. Barry Eppley
Indianapolis, Indiana