Background: The bony genioplasty remains the best technique for significant lower facial augmentation particularly when significant vertical lengthening is needed. It is always better in the long term to let the bone create the large chin augmentation effect as opposed to a large implant load on the chin even if it may not create the patient’s ideal projection or chin shape. An implant can always be added later to the advanced bone for a maximal chin augmentation change.
In some cases when only a minor additional augmentation change is needed, usually for a horizontal increase, the placement of a standard chin implant may suffice. But when a multidimensional effect is needed and a specific shape desired a custom implant design is needed.
Case Study: This male had a prior vertical chin lengthening of 10mms by an opening wedge osteotomy and interpositional bone graft. His improvement was significant but still not quite what he ideally wanted.
His ideal chin-jaw change was seen in his jaw thrust manuever. Given from where he started his change was good but not quite enough with the bone movement alone.
A custom chin implant was designed on top of the advanced chin bone in which an additional 8mms of vertical length and 4mms of horizontal projection was added. In addition a very square chin shape was also incorporated into the design.
Under general anesthesia and through a submental incision the chin bone and the lower end of the fixation plate was identified.
The square chin implant had an imprint of the fixation plate on is inner surface to aid placement.
The square chin implant was placed and secured with a single drilled 2 x 13 mm screw to the bone.
When adding an implant onto a prior genioplasty the question is always how much more additional augmentation can the soft tissue chin pad be stretched to accommodate an implant. Usually I would not have expected an implant with these additional dimensions to fit. But a full submental release of all the soft tissue high up onto the chin made it possible.
Key Points:
1) A vertical lengthening bony genioplasty can provide significant improvement in lower facial proportions but may not be able to achieve the patient’s ideal chin augmentation/shape effect.
2) An implant can be added secondarily to a bony genioplasty for additional augmentation effects which is most ideally done using a custom implant design.
3) The submental incision is usually the best approach to place an implant after a bony genioplasty particularly if additional vertical length is desired.
Dr. Barry Eppley
World-Renowned Plastic Surgeon