Background: The sagittal split ramus osteotomy (SRRO) of the mandible is the most common form of lower jaw reshaping/repositioning. While a very effective procedure its aesthetic benefits are sagittal in dimension only. It can bring the lower jaw and chin forward to improve lower facial projection but it can widen the chin or jawline and has a limited ability to make specific vertical changes as well.
In some cases of SSROs the existing shape of the jaw angles can become deformed or aesthetically worsened. This can occur because of how the two split segments of the ramus were put together with the distal segment advancement or some bone atrophy of the proximal bone segment can occur. Regardless of the cause alteration in the shape of the jaw angle after orthognathic surgery are not rare. Having seen many after mandibular osteotomy 3D CT scans more pronounced antegonial notching (or even the creation of an antegonial notch that did not exist before surgery), blurting of the actual gonial angle and thinning of the bony ramus width are typical changes I have observed.
To create a finishing 3D effect of the bony jawline implant augmentation is needed. While standard jaw angle implants have their role in primary jaw augmentation a history of SSRO introduces variables in the shape of the bone along with the presence of fixation hardware that makes their use aesthetically risky. A custom jawline approach is always more predictable and can account for jaw asymmetries and the presence of plates and screws.
Case Study: This male had a prior history of double jaw surgery for obstructive sleep apnea as well as infraorbital-malar implants to address the upper part of the midface that was ‘left behind. He had a sliding genioplasty with his jaw surgery so his chin projection was adequate. To improve the aesthetic outcome of his prior jaw surgery he desired more visible jaw angles and correction of their asymmetry. While he was not unhappy with his chin some enhancement and a bit more squareness to it would be a bonus
A custom wrap around jawline implant was designed to provide an enhancement along the entire jawline and improve the shape and asymmetries of the jaw angle areas which had been adversely affected by the SSROs.
The jawline implant was placed through the traditional three incisional approach, single submental skin and paired intraorak posterior vestibular mucosal incisions. One of the keys to placement of a custom jawline implant after its introduction is to set the central chin position and then stretch out the rest of the implant back to the jaw angles. While one screw sets the midline when in doubt about any tilt to the chin set its corners/sides with an additional screw on each side to keep it horizontally level.
Not every custom jawline implant is done to create a larger lower jaw or make bold changes. An equal number are done to merely enhance a jawline that needs a little more shape on which the jawline implant is relatively small. The SSRO has already done a significant part of the aesthetic ‘work’ of the lower face as seen in this patient. The jawline implant merely provides the finishing 3D touches to a good bony foundation.
Case Highlights:
1) Fixing jawline defects and/or improving the shape of the lower jaw after a sagittal split osteotomy requires a custom jawline implant.
2) Loss of jaw angle shape and adding width is the primary benefit of the posterior portion of the jawline implant.
3) The existing hardware from the sagittal split osteotomy does not need to be removed and actually helps with the placement of the jawline implant.
Dr. Barry Eppley
World-Renowned Plastic Surgeon