Head Position and CEPHs Question (examples from my case)

[Post bimax]

What impact does head position during a CEPH x-ray have on surgical planning and perceived OP steepness?  Are these values standardized?

In my case, I had my CEPHs taken at the orthodontist's office (which was also my childhood ortho) rather than with the surgeon.  The technicians there didn't know much about the x-rays or their purpose. My first CEPH was sent to my surgeon's office but the surgeon asked for the CEPH to be retaken because the chin was partially cut off in the image.  Rather than adjusting the height of the machine, the technician asked me to tilt up my head and jut out my chin so it would not be cut off vertically.  This retake was the CEPH used for my surgical planning.

Here is a link to the CEPHs.  I also included a CEPH taken in 2011 where I am at or close to 'neutral head posture', as well as my post-op CEPH which is also relatively neutral.  To me, it looks like tilting my head up for the planning CEPH flattened my OP relative to the 'true' horizontal, whereas my OP is steeper when in neutral head posture.  My question is whether this likely had an impact on my surgical planning and any decisions to do CW or CCW rotation. In my other post, the CEPH I included was actually the 2011 CEPH. I did not realize this until after I posted.

CEPHs are in chronological order with dates and labels:

https://imgur.com/a/G8mbkWC

I know there are normalizing planes like the FH, but I'm also wondering how often they are used and whether head posture could somehow skew differentials between those as well. Thanks

[kavan]

The post op one is more of an X ray than a ceph. Cephs show soft tissue contour.

For head position, they want to see the 'pure' horizont and vertical via the cepholostat and they want the cepholostat where you have it (glabella /root of nose region) in the 2 cephs that are not 'rejected'. The 'pure' horizont of the Cstat allows them to see how your own horizontal planes line up. Not everyone's Frankfort 'horizontal' is a 'pure' horizont.

Your OP is on the 'flat' side on your 6/1/2018 'accepted' pre-op, whether or not you used that one in your first post. Your ANS-PNS is oriented already in CCW  relative to the pure horizont of the C stat.

If they wanted to compare your OP with your other 'horizontal' planes of reference such as porion to orbitale or sella turica to nasion, they could do that too.

If one 'plane' is tilted --via a head posture-- by a predictable amount (angle) with reference to the Cstat pure horizont, the rest should be tilted by similar degree.

[PloskoPlus]

I could be wrong, but it looks like your maxilla was downngrafted at the front and you were actually CW rotated.

[Post bimax]

Kavan- Thanks, I wasn’t sure exactly how cephs are interpreted. I was basically wondering if my OP only “looks” flat in the ‘accepted’ ceph that was used for my planning because my head is tilted upward rather than neutral.

Plosko- I think so as well, looks like he closed my AOB via anterior downgraft instead of posterior impaction. I’m actually shocked my tooth show is almost exactly the same with 10mm advancement and anterior downgraft. Kavan’s point about my ANS-PNS being in CCW orientation is making me wonder whether a revision would be worth it. I think I’d only do it if CCW-r would be an option. Otherwise I think I’d just want to augment my lower 1/3 somehow. The chimp-lip is annoying, but the bigger problem (for me) is the relative weakness in the lower 1/3 it creates. Not sure I’d be willing to undergo a full bimax revision just for linear setback. Plus I’d have to get a larger genio in the process because I do want the lower jaw length.

[PloskoPlus]

Kavan- Thanks, I wasn’t sure exactly how cephs are interpreted. I was basically wondering if my OP only “looks” flat in the ‘accepted’ ceph that was used for my planning because my head is tilted upward rather than neutral.

Plosko- I think so as well, looks like he closed my AOB via anterior downgraft instead of posterior impaction. I’m actually shocked my tooth show is almost exactly the same with 10mm advancement and anterior downgraft. Kavan’s point about my ANS-PNS being in CCW orientation is making me wonder whether a revision would be worth it. I think I’d only do it if CCW-r would be an option. Otherwise I think I’d just want to augment my lower 1/3 somehow. The chimp-lip is annoying, but the bigger problem (for me) is the relative weakness in the lower 1/3 it creates. Not sure I’d be willing to undergo a full bimax revision just for linear setback. Plus I’d have to get a larger genio in the process because I do want the lower jaw length.

A posterior downgraft would swing your mandible up and increase the overjet. Your maxilla could then be set back. If anything, your genio would then probably need to be reversed.

[Post bimax]

A posterior downgraft would swing your mandible up and increase the overjet. Your maxilla could then be set back. If anything, your genio would then probably need to be reversed.

Yeah I know, but I don’t know if I could get a posterior downgraft as Kavan is saying my OP is on the flatter side already

[PloskoPlus]

Yeah I know, but I don’t know if I could get a posterior downgraft as Kavan is saying my OP is on the flatter side already

It's not flat anymore.

[Post bimax]

It's not flat anymore.

The downgraft was extremely minimal, my AOB was about 2mm. If you look at my OP in the 2011 CEPH, it’s the same as the post-op CEPH. The pre-op 2018 one only looks flatter because my head is tilted up as instructed by the technicians so my chin wasn’t cut off vertically in the image.  My bones didn’t change much between 2011 and 2018, it’s just head position.  So I’m confused- is my OP steep now and was it steep pre-op too?

[kavan]

The downgraft was extremely minimal, my AOB was about 2mm. If you look at my OP in the 2011 CEPH, it’s the same as the post-op CEPH. The pre-op 2018 one only looks flatter because my head is tilted up as instructed by the technicians so my chin wasn’t cut off vertically in the image.  My bones didn’t change much between 2011 and 2018, it’s just head position.  So I’m confused- is my OP steep now and was it steep pre-op too?

The norms for OP angles are in the range of 4-12 degrees (relative to a Frankfort horizont). Because there is double imaging in your cephs, I can't get a precise OP angle measure. But that doesn't matter because:

a: You are within the norms and most certainly DON'T have a 'steep' OP.

b: Even though there might be some error in looking for an 'exact' OP angle, one can always just draw lines through the SAME areas and get a DIFFERENTIAL  providing one is conversant in basic geometrical principles.

You wanted to know about head position. The important thing about it as far as comparisons go is that one needs to look at a constant 'plane' (actually, a LINE on a ceph) to see if head position on both diagrams is consistent with the same inclination angle. For example a 'constant' plane (or line) could be a 'pure' horizont. The line on the before ceph can be drawn through 2 of the SAME points. Likewise on the after X-ray providing that the points they are drawn through are not changed via the surgery. So, if I draw a line though the 'S' point and the 'Or' point in a before and find that a similar line drawn through the same points in the after is rotated 'X' degrees away from that in the CW direction, it means the other measures have to be calibrated by 'X' degrees.

For example, your ANS- PNS on the after has 'X' degrees more CW than the before as does an approximation of your OP. So, although your OP is 'not flat anymore' (as Plosko said), it's not 'flat anymore' by the same 'X' degree differential I found for the head orientation on the before (2018) vs the after X ray.

Since this is all very tedious to explain via diagrams, measures etc. and tends to invite extraneous questions from others or contentions that 'you need CCW', for now, I'd prefer that Plosko show you via diagrams, measures etc just how much 'not flat anymore' he measured and then I will show mine.

[kavan]

Also, see if you can get a ceph TRACING of your before, especially of the maxilla area. It could be possible that you don't have much of a conCAVITY at the 'A' point area. Your cephs are too fuzzy for me to trace in absence of clear outline. But I would like to look to see IF you have a conCAVE area at the 'A' point. I suspect you might not. But I would need to see a ceph tracing .

[Post bimax]

The norms for OP angles are in the range of 4-12 degrees (relative to a Frankfort horizont). Because there is double imaging in your cephs, I can't get a precise OP angle measure. But that doesn't matter because:

a: You are within the norms and most certainly DON'T have a 'steep' OP.

Okay, this was my main concern.  I understand your explanation about the differential and I think you alluded to as much on my first post.  I'm sure some surgeons would do ccw even within +- 1 standard deviation but I don't know what this would mean in terms of overall displacements.  Would have to consult to see.

As far as ceph tracing for the A point, I could try to obtain this but I never even viewed it myself if Posnick made one.  All of the planning was communicated to me verbally.  TBH I don't even have a record of the displacements I got or was promised, he just told me.  During the planning consult just prior to the surgery he actually told me the software indicated 12mm of advancement whereas the clinical photos indicated 8mm.  I had no idea what to do with this information so I just said let's split the difference.

Are you asking because this would affect the lip curve over the bone?  I wonder if bone shaving of this area is possible to induce concavity.

[PloskoPlus]

Okay, this was my main concern.  I understand your explanation about the differential and I think you alluded to as much on my first post.  I'm sure some surgeons would do ccw even within +- 1 standard deviation but I don't know what this would mean in terms of overall displacements.  Would have to consult to see.

As far as ceph tracing for the A point, I could try to obtain this but I never even viewed it myself if Posnick made one.  All of the planning was communicated to me verbally.  TBH I don't even have a record of the displacements I got or was promised, he just told me.  During the planning consult just prior to the surgery he actually told me the software indicated 12mm of advancement whereas the clinical photos indicated 8mm.  I had no idea what to do with this information so I just said let's split the difference.

Are you asking because this would affect the lip curve over the bone?  I wonder if bone shaving of this area is possible to induce concavity.

Bone shaving won't work.

[kavan]

Okay, this was my main concern.  I understand your explanation about the differential and I think you alluded to as much on my first post.  I'm sure some surgeons would do ccw even within +- 1 standard deviation but I don't know what this would mean in terms of overall displacements.  Would have to consult to see.

As far as ceph tracing for the A point, I could try to obtain this but I never even viewed it myself if Posnick made one.  All of the planning was communicated to me verbally.  TBH I don't even have a record of the displacements I got or was promised, he just told me.  During the planning consult just prior to the surgery he actually told me the software indicated 12mm of advancement whereas the clinical photos indicated 8mm.  I had no idea what to do with this information so I just said let's split the difference.

Are you asking because this would affect the lip curve over the bone?  I wonder if bone shaving of this area is possible to induce concavity.

Here's the thing:

1: The 'A' point is in the conCAVE area which I've circled and pointed to in red. Note how there is clearly an outline where someone without experience in radiology could easily see the contour and trace it.

2: The TRACING of the area albeit at a later stage of some treatment but still, the outline where one would see the conCAVE area where the 'A' point is located is clearly visible.

3: On yours, the outline where I would want to see the conCAVE curve is not clear. Not enough for me to trace it. Basically, it looks like there could be some curve in there but I don't know if the semi-opaque area that looks kind of straight is a DIFFERENT STRUCTURE or just some image fuzziness from something else.

Basically, what I see on your ceph is a straight looking area to where I can see a conCAVE area in the example cephs. With that, I see (which is clear to see) an OVERLY OBTUSE nose to lip angle.  The MYSTERY to me, at least, is; 'Do you have the type of bone contour to the anterior maxilla that's just NOT going to look good with any advancement, no matter what the rotation. I don't know. I mean what I could tell by looking at the soft tissue contour of your ceph (nose to lip angle) is that it wouldn't take much advancement at all to turn the overly obtuse nose to lip angle into a conVEXity. That's just something that is intuitively obvious to me.

As I understand it, your main motivation for getting revision surgery is BECAUSE of the conVEX lip contour. So, you would have to establish from whom ever you elect to revise whether or not you have a type of contour that can either be altered so that when it's moved forward, you're left with a BETTER contour OR if it's just one of those things they can't do much about.

For a revision, they would need to go through the SAME cut you had prior and most likely make other cuts (multi segment lefort) to make separate alterations to the anterior and posterior maxilla.

All I can say from here is that the doctor who did your surgery did not 'put' that straightish looking bony contour you have going on to the anterior maxilla there. He just moved it forward (and a little down) along an ANS-PNS plane that was already oriented in the CCW direction and your post op still shows a CCW ANS-PNS orientation even though you got CW to close the anterior open bite. However, the '64 thousand dollar question' is whether or not a 3 piece Lefort for more CCW to posterior maxilla and separate alteration to anterior maxilla would be the 'solution' to fixing your lip contour. Like, I DON'T KNOW if they can carve in a conCAVE area where it looks like you didn't have much of one from your start point.

TBH, I don't know what type of osteotomy or even if there is one to fix what looks to be a type of contour that's just not 'receptive' to looking better when advanced forward. BUT IF there WERE one where they could just RE-CONTOUR what looks to be the problem area, you'd be all set and would not have to have the whole thing cut through again and with multi-segment lefort.

So, there you have it. I 'know what I don't know' and it's beyond me to tell you that getting revision surgery with more CCW (probably via multi segment lefort) is going to target the problem of the conVEX nose to lip contour you want to fix. What I can tell you is that you would need to TARGET your consults to FOCUS on the 'mystery' I'm not to sure about.

[Post bimax]

Here's the thing:

1: The 'A' point is in the conCAVE area which I've circled and pointed to in red. Note how there is clearly an outline where someone without experience in radiology could easily see the contour and trace it.

2: The TRACING of the area albeit at a later stage of some treatment but still, the outline where one would see the conCAVE area where the 'A' point is located is clearly visible.

3: On yours, the outline where I would want to see the conCAVE curve is not clear. Not enough for me to trace it. Basically, it looks like there could be some curve in there but I don't know if the semi-opaque area that looks kind of straight is a DIFFERENT STRUCTURE or just some image fuzziness from something else.

Basically, what I see on your ceph is a straight looking area to where I can see a conCAVE area in the example cephs. With that, I see (which is clear to see) an OVERLY OBTUSE nose to lip angle.  The MYSTERY to me, at least, is; 'Do you have the type of bone contour to the anterior maxilla that's just NOT going to look good with any advancement, no matter what the rotation. I don't know. I mean what I could tell by looking at the soft tissue contour of your ceph (nose to lip angle) is that it wouldn't take much advancement at all to turn the overly obtuse nose to lip angle into a conVEXity. That's just something that is intuitively obvious to me.

As I understand it, your main motivation for getting revision surgery is BECAUSE of the conVEX lip contour. So, you would have to establish from whom ever you elect to revise whether or not you have a type of contour that can either be altered so that when it's moved forward, you're left with a BETTER contour OR if it's just one of those things they can't do much about.

For a revision, they would need to go through the SAME cut you had prior and most likely make other cuts (multi segment lefort) to make separate alterations to the anterior and posterior maxilla.

All I can say from here is that the doctor who did your surgery did not 'put' that straightish looking bony contour you have going on to the anterior maxilla there. He just moved it forward (and a little down) along an ANS-PNS plane that was already oriented in the CCW direction and your post op still shows a CCW ANS-PNS orientation even though you got CW to close the anterior open bite. However, the '64 thousand dollar question' is whether or not a 3 piece Lefort for more CCW to posterior maxilla and separate alteration to anterior maxilla would be the 'solution' to fixing your lip contour. Like, I DON'T KNOW if they can carve in a conCAVE area where it looks like you didn't have much of one from your start point.

TBH, I don't know what type of osteotomy or even if there is one to fix what looks to be a type of contour that's just not 'receptive' to looking better when advanced forward. BUT IF there WERE one where they could just RE-CONTOUR what looks to be the problem area, you'd be all set and would not have to have the whole thing cut through again and with multi-segment lefort.

So, there you have it. I 'know what I don't know' and it's beyond me to tell you that getting revision surgery with more CCW (probably via multi segment lefort) is going to target the problem of the conVEX nose to lip contour you want to fix. What I can tell you is that you would need to TARGET your consults to FOCUS on the 'mystery' I'm not to sure about.

I'll take the bone curvature of this A point into account if/when I do further consults and ask what can be done in terms of contouring this area.  As I stated before, I do dislike the lip contour but my bigger problem is the dominance of my maxilla as you can see in these pics I took a couple days ago here:

https://imgur.com/a/AH5jLjt

I'd hope a revision could involve a setback of both jaws with ccw-r to help compensate the relative weakness of my chin.  I'll also now ask about my anterior maxilla contour and whether there are any osteotomies to address it if necessary.

Even if my lip contour isn't perfect, I really just want a relatively stronger lower jaw/weaker maxilla area.  I feel the surgery gave my face more overall structure at the expense of actually exaggerating the convexity of my profile.

[kavan]

I'll take the bone curvature of this A point into account if/when I do further consults and ask what can be done in terms of contouring this area.  As I stated before, I do dislike the lip contour but my bigger problem is the dominance of my maxilla as you can see in these pics I took a couple days ago here:

https://imgur.com/a/AH5jLjt

I'd hope a revision could involve a setback of both jaws with ccw-r to help compensate the relative weakness of my chin.  I'll also now ask about my anterior maxilla contour and whether there are any osteotomies to address it if necessary.

Even if my lip contour isn't perfect, I really just want a relatively stronger lower jaw/weaker maxilla area.  I feel the surgery gave my face more overall structure at the expense of actually exaggerating the convexity of my profile.

Well, you don't have what would be called convex PROFILE. It's just convex upper lip. Plosko just said, that area can't be shaved down and I have no reason to think it can.

Here. I just did the most minor of minor changes to the soft tissue contour of the lip and it makes a BIG difference. Find some plastic surgeon who's good at fixing lips.