Help with deciphering surgeon plan- potential changes to alar base (widening)?

[Ember22]

CCW allows for a smaller movement of the maxilla relative to the mandible because the occlusal plane is rotated counter-clockwise. This helps mitigate side effects that usually accompany maxillary advancement because the maxilla doesn’t need to be moved horizontally as much. You can still have some nostril widening/tip upturning even with CCW, but it’s less than if you got a larger straight advancement.

Thanks for chiming in. I do understand that a greater advancement would be neccessary to accomodate the steep plane if I opted for just lefort 1. I don't quite get what is Gunson talking about when he says the base of the nose will be better supported with CCW.  To my understanding, it was implied that this support would prevent negative changes to that area. Maybe I just misunderstood what he said. On the diagram, the ANS and PNS are moving forward and upward which at least creates a fuller upper lip and shortened philtrum, but how much support does this actually provide.

[Ember22]

Well, CCW via anterior impaction (where ANS is moving UP) will certainly help make less what looks like a long anterior maxilla (where it looks like you have excess upper tooth show and/or too much gum show) and it will help auto rotate lower jaw in CCW to make less the steep mandibular plane angle and also make less the OP which all together clearly kick up a profile improvement.  Also, CCW is done to mitigate--make less--unfavorable changes to the nose base. But it doesn't guarantee to PRECLUDE any unfavorable nose base change just because it's CCW.

Ultimately, you would need to SEE that the contour changes of the profile (shown in the displacement diagram) are WORTH IT improvements for you and weigh the profile improvements with a possibility of having base of the nose change--from the front-- you might not like.

Thank you for clarifying the proposed displacements.  Could you just clarify, are the A-P changes to the ANS or PNS generally what people are talking about when they say they were advanced X mm (in regard to maxilla)?  Just a bit unclear on that.  My orthodontist said I'd probably have a 2 or 3 mm advancement, so that would make sense

[Ember22]

The proposed movements are small, and apparently that alone decreases the risk of adverse aesthetic changes to my nasal base area.  Curious, at what point, or number mm advancement do these changes become less predictable? 
 I think I'm willing to move forward because a functional bite alleviates future periodontal concerns, my lips will touch at rest, etc.. I just hate the thought of my nose potentially changing for the worse.

[kavan]

Thank you for clarifying the proposed displacements.  Could you just clarify, are the A-P changes to the ANS or PNS generally what people are talking about when they say they were advanced X mm (in regard to maxilla)?  Just a bit unclear on that.  My orthodontist said I'd probably have a 2 or 3 mm advancement, so that would make sense

Movement of any one part takes place over a diagonal. So there will be 2 components; a pure horizont and a pure vertical. The A-P direction is the pure horizontal component and the Vertical being the pure vertical component. For example when you look at the read out for the ANS, the A-P is the pure horizont and the vertical is the pure vertical displacement. Hence the whole movement is along a diagonal.

[Ember22]

Movement of any one part takes place over a diagonal. So there will be 2 components; a pure horizont and a pure vertical. The A-P direction is the pure horizontal component and the Vertical being the pure vertical component. For example when you look at the read out for the ANS, the A-P is the pure horizont and the vertical is the pure vertical displacement. Hence the whole movement is along a diagonal.

Oh yes, of course, movement will occur horizontally and vertically here... What a dumb question. I guess I was thinking about just horizontal movement for some reason. Thanks anyway

[kavan]

Hmm, I thought whatever the cephalometric landmark, horizontal + means forward and - means back.  Vertical + means down, - means up. It sort of makes sense + for downgrafting, advancement, - for impaction, setback.

The A-P for BOTH maxilla and mandible is more straight forward/consistent where a + is horizontally forward in both and a - is horizontally backward in both maxilla and mandible.

Now vertical directions (+ or -) for the MAXILLA are more straight forward too because when we see a + sign for the PNS (as in posterior downgraft), we know the + sign refers to that area (and all other areas to the maxilla with a + sign) being moved down. Hence a - sign for the maxilla refers to that area being moved up. But that's just for the maxilla.

Now for the mandible it's reversed. A + sign refers to an area moving vertically up and a minus sign refers to an area moving vertically down. Well, at least that has been the case of other cephs displacement diagrams I've looked at where the read outs give a + or -.

So, other people's ceph displacement diagrams where you can look at both the + and - directions for the mandible show that a - sign means downward vertical and + means upward vertical.

If you look at other people's ceph displacement diagrams for the MANDIBLE where they also give the read outs, you will see that something going vertically DOWN is marked with a - sign and something going vertically UP is marked with a + sign.

So, NO IDEA why the OP's vertical readout for the mandibular displacement were all - (negative signs) when that usually means vertically DOWN because the ceph displacement diagram shows all the parts moving up. Maybe they reverse the signs for anterior impaction but IDK.

Oh well, NEXT TIME, I shall request people put up the WHOLE document where both the displacement diagram and the read outs can be seen together.