Introduction
A vertical lengthening bony genioplasty (VLBG) adjusts the chin (symphysis) by moving the lower segment downward to increase lower facial height.A custom jawline implant addresses the entire jawline: chin width, jawline length, ramus width, gonial angles, and overall contour.
When performed together:
- The bone movement fixes the vertical deficiency.
- The implant restores or enhances the 3-dimensional shape around the newly lengthened chin.
This avoids the “hollow,” “step-off,” or “narrowed” look that can occur when the chin is dropped vertically without addressing the surrounding jawline.
But the two can and are often done separately and are done so for the following reasons:
1. Gap along the inferior border
Lowering the chin creates:
- A vertical gap under the osteotomy
- A visible step along the inferior mandibular border
A custom implant smooths this step and restores a continuous lower jaw contour.
2. Widening the chin
Lengthening vertically often makes the chin appear:
- Narrower
- Less defined
- Slightly pointed
A custom implant can widen the chin and give it stronger shape.
3. Harmonizing the entire jawline
VLBG only moves the chin segment.
A custom implant:
- Extends definition posteriorly to the jaw angles
- Adds horizontal projection or width as needed
- Balances the jaw in 3D
4. Enhancing gonial angles
If the chin is lengthened vertically, the gonial angle may look relatively high.
A custom implant can:
- Drop the angles
- Widen them
- Give stronger shape to match the new chin height
5. Correcting asymmetries
During the design process (CT-based), a custom implant can fix:
- Left–right chin asymmetry
- Ramus asymmetry
- Jawline curve irregularities
Case Study
This young male had double jaw surgery but it still left him with a less than ideal facial shape/proportions. His most obvious facial deficiency was a vertoicallhy short chin and a bunched up soft tissue chin pad with a central dimple. This was treated by a 12mm vertical lengthening bony genioplasty which went on to heal uneventfully.
While the genioplasty was very helpful he then desired the rest of the jawline behind it to have a more proportionate shape and an overall better defined jawline. A wrap around custom jawline implant was designed to achieve that effect. Its primary benefit was to augment the rest of the jawline behind the chin. It wrapped areound the chin for a smooth linear jawline shape and to create a more square chin shape.
The 18 month long term results showed the combined improvement provided by the bony genioplasty and custom jawline implant from the unintended but necessary two stage jaw augmentation procedure after double jaw surgery.
Discussion
The aesthetic benefits of a secondary custom jawline implant after a VLBG are:
More Vertical Height
The bone move gives structural vertical length.
More Jawline Definition
The implant creates:
- A straighter mandibular border
- A stronger look under the masseters
- Clearer definition between neck and jaw
Better Chin Symmetry & Shape
The implant fixes width or asymmetry that bone movement alone cannot.
Balanced Proportions
Jaw angles and chin height now match, creating a proportionate lower third of the face.
Jawline implant design considerations specific to post-genioplasty patients are:
CT-based design
A postoperative CT is ideal so the implant is designed on the actual new bone shape.
Thicker inferior border build-out
The designer compensates for the lowered bone segment by building additional thickness at the bottom border.
Screw fixation zones
With VL genioplasty plates already present, the custom implant is designed to:
- Avoid hardware
- Avoid nerve exit points
- Use screw channels in the best remaining bone areas
Soft tissue implications
After vertical lengthening, soft tissue tension increases.
The implant must account for:
- Stretch capacity
- Risk of labiomental fold deepening
- Soft tissue drape over the new chin height
Key Points
- The vertical lengthening bony genioplasty can create a mismatch with the jawline behind it at the inferior border level.
- The custom jawline implant after a b9ny genioplasty provides a connected and proportionate lower third of the face shape.
- The chin portion of the implant adds shape while the rest of the implant provides volume and shape to the deficient jaw behind the chin.
Dr. Barry Eppley
World-Renowned Plastic Surgeon