Background: Chin implants are the original form of permanent facial augmentation and are still the most commonly performed aesthetic implant today. But chin implants only cause an incomplete jaw augmentation effect. The jaw angles behind the chin on both sides provide a fertile area for additional aesthetic augmentations for a different type of jaw enhancement. Or combined with a chin implant to have a more complete jaw augmentation.
As a result jaw angle implants have been available as a standard type of facial implant since the 1990s. But they were never very popular after their inception probably due to lack of patient demand with low appreciation for the benefits of posterior jaw angle augmentation. The other reason jaw angle implants, until recently, have never achieved surgical popularity is the difficulty in their surgical placement.
Placed through an intraoral approach way back in the posterior vestibule, the implant pocket needs to be developed under the thick and strong masseter muscle. Getting the working end of a jaw angle implant back along the posterior and inferior ramus border is also complicated by the tight ligamentous attachments of the muscle which happen to attach exactly where the implant needs to be. The difficulties of the anatomy combined with the need for bilateral implant placements makes postoperative complications with their use the highest amongst all facial implants.
Case Study: This young male had standard widening jaw angle implants placed intraorally after which he knew immediately that their position was not correct. They made him feel very ‘cheeky’ but was reassured that it was just postoperative swelling. A 3D CT scan done later confirmed how inadequate their placement was.
From the side view the implants could be seen to have a high and anterior malpositioning. With the working end of the implant closer to the cheeks, it is easy to see why he felt cheeky after the surgery.
He opted to replace these standard jaw angle implants with custom designed implants. His original goal remained the same…a more defined jaw angle appearance.
Under general anesthesia and through his existing intraoral scars the misplaced jaw angle implants were removed. With placing the new implants besides breaking through the implant capsules it was necessary to remove the areas of bony overgrowth that had occurred around the removed implants. (in green) Failure to do so will prevent the implant replacements from getting into proper position.
When seen months later the improvement in his facial shape is seen. It will take four to six months after the replacement surgery to see the complete effect of the implant exchange.
This case shows some of the classic positioning errors that can occur in performing jaw angle implant surgery…in an extreme form. It is very easy to under estimate how far back the posterior border of the jaw angles are. It is not as easy as making an incision, developing a quick pocket and simply stuffing the implants into the limited pocket. This results shows how inexperienced the surgeon must have been with the procedure…it likely was the first time it had been performed.
Jaw angle implants requite a lot of experience to learn the nuances of how to achieve proper positioning over the jaw angles. This becomes even more paramount when doing implant exchanges as the anatomy is now scarred and bone overgrowths have occurred. A custom implant is certainly beneficial but an inability to get the implants into proper position will still result in an aesthetic failure.
Key Points:
1) Jaw angle implants are the most challenging of all facial implants to intraoperatively place.
2) Anterior and superior malpositioning is the most common location of improperly placed jaw angle implants.
3) Custom designed jaw angle implants are often the choice to replace malpositioned standard implants.
Dr. Barry Eppley
World-Renowned Plastic Surgeon