Of all the common sites of aesthetic facial implant augmentation, the jaw angles in my experience pose the greatest challenges. Not only getting the correct dimensional shape for each patient defies any conventional measurements but they are also the most difficult to accurately place in the correct position on the bone. Placing an implant through an incision deep in the back recesses of the mouth where the working end of the implant is not visible once placed is why they have a significant risk of implant malpositon and asymmetry.
One of the common reasons for jaw angle implant asymmetry is that the patient had underlying jaw bone asymmetry initially. Covered up by the thick masseter muscle and subcutaneous tissue cover modest amounts of jaw asymmetry may be easily overlooked or deemed of no aesthetic consequence. Then when the jaw angles are enlarged the jaw asymmetry becomes more obvious…and even becomes further magnified if the implants have asymmetrical positions on the bone.
Recognized jaw asymmetry is one compelling reason for custom jaw angle implant designs. At the least such an approach factors in the bony asymmetry and creates a matched pair of implants. They still have to have the correct size and shape for the intended effect and have to be surgically placed as designed. (both of which have their own challenges) But it takes all three to have a good aesthetic result. But the design of the implants at least accounts for 2/3s of the reasons jaw angle implant augmentations can end up with an asymmetrical result.
The magnitude of jaw angle asymmetry is what often fools the surgeon and the patient. Major jaw asymmetry is easy to spot and few would argue with the need for custom implant designs to treat it. But it is the more modest or lesser amounts of asymmetry that can be deceiving. What appears as a small amount of asymmetry externally is more significant than one realizes at the bone level.
Dr. Barry Eppley
Indianapolis, Indiana