It was a lot.
Of topic:
When thinking about the sagittal split I started to imagine a sagittal split genioplasty asking myself if this is possible or has been done. And apparently it is/was.
https://www.joms.org/article/S0278-2391(09)01824-2/abstract
I don't have full access to that article. But the part I can read, the author (Stephen Schendal MD) states:
"The most frequently performed osteotomy for correction of the small and retruded chin is the horizontal sliding genioplasty". That doesn't ring true to me simply because a sliding genio can include a diagonally oriented cut for the sliding to have vectorial components of horizontally outward and vertically upward. I don't know about his contention that horizontal ones are the most frequently used (a sliding genio with no vertically upward vector component). Maybe a matter of semantics. However, it is true that sliding genio; horizontally displaced or diagonally upward can kick up some scalloping to what they call the 'pre-jowl sulcus' area which is the part of the mandibular border lateral to* and close to the chin itself.
Again, I don't see the illustrations for what he calls a sagittal split genio. But what I do 'see' (in my head) is that on Figure 2 of his illustration (pointing to the area that can show scalloping with the 'horizontal' sliding genio) that the cut could be extended to include some of the body of the anterior part of the mandibular border.
*Note the pre-jowl sulcus area is next to the chin (lateral to). It's on the anterior aspect of the border of the body of the mandible.
You know how in SOME chin wings (with some people), they can't angle the cut all the way back to the posterior part of the mandibular border because the person's nerve hole is too close for comfort. Well, that type of chin wing can include some of the anterior aspect of the mandibular border. One time I called that a 'glorified genio' (which would not be the 'medical name for it). So, maybe he's extending the cut to include that area which would tend to mitigate scalloping. Again, I don't see what his cut is because I don't have full access to the article. I'm just using my imagination of what it could be.
ETA: OK. I found some illustration that seems to show he is including part of the anterior aspect of the mandibular border.
ETA #2: OK, still can't see more illustrations. But if it's a sagittal cut it's dividing something vertically. So, it looks like a curved cut that includes the anterior aspect of mandibular border that extends downward to release that chin segment.
ETA #3: If you wanted a type of genio that mitigated scalloping (the look of step-offs), the type of 'patient speak' to the doctor would be: 'I'd like a type of genio that also includes the part of the mandible right next to the chin because I'm concerned about step-offs with some other types.'
