Bimax or just BSSO? Conflicting opinions are making decision difficult

[emanresu]

It's just that you spring boarded from his (clueless) question by introducing complexities that had nothing to do with the basic response to his question. Not to say that you don't have a complex face case which I could help explain but there is a sense of futility on my part to give an explanation if I've gotta wonder if I've gotta go over basic geometry to do it. Not saying you wouldn't understand.  But I was not up to clearing confusion that looked like it arose from HIS question and my basic response to it.

SNA values when high are indicative of RELATIVE protrusion (upper jaw). But BOTH jaws can be retrusive and really retrusive and/or under developed which is your case. Your case is also complicated because you have bi-max protrusion along with the double jaw retrusion.
Yes. Maxfax's have another way of looking at double jaw retrusion and they can do it without 'converting any angles' into something else. They drop a vertical from a selected area near the forehead and take a look at whether or not the jaws are too far behind that line. Just trying to keep it simple here.

ETA: To clarify he had both double jaw retrusion with bi max protrusion.

I appreciate the response kavan, and I’m sorry for my delay responding back, I’ve just now had the time to do so.

As I was writing this, I was struggling to unpack my thoughts on the topic, so I can only imagine how difficult it was for you when responding to me previously, when I couldn't even properly explain to myself where I stood. I also just want to say I completely understand any reluctance you’d have towards engaging when there may not even be a mutual basis of understanding, as I’m sure you grapple with that on a daily basis here on the forum. I’ll try my best moving forward to offer some context on my understanding of a topic when I post.

As you say, SNA indicates relative protrusion. This concept is pretty simple to grasp, but it does have its intricacies, as relative protrusion, by definition, could really be caused by any number of things in regards to the relationships that points S, N, and A, have with each other. However, in my case, with SN − FH being normal, I think my high SNA mostly comes down to one of two things: either N being too backward, or A being too forward (or both). But while SNA indicates relative protrusion, even if the relative protrusion is being caused by the nasion being too backward, when looking at the face, aesthetically speaking, the protrusion probably still appears to be due to the maxilla, not the nasion. So, in a way, at least from a strictly aesthetic perspective, it’s almost as if the high SNA directly equates with the maxilla's appearance of being too far forward (assuming things like SN − FH are within normal range). So although my upper jaw is technically underdeveloped and the roots of the incisors stick out, I can’t help but wonder: if my maxilla already appears protrusive comparatively, is it worth correcting the underdevelopment problem if the end result is going to make the maxilla/midface look even more protrusive/over-advanced? (even with CCW)

Also, although it’s the high SNA which initially made me concerned enough to ask this question in the first place, I just want to now make the distinction that I’m not attributing my protrusion specifically to the high SNA, but rather that because of the high SNA, I’m now just concerned about the possibility that I have a protrusive maxilla/midface in general, regardless of SNA. Are there any other tools or measurements I can use to determine the potentiality of over-protrusion? Is this vertical line you mention the nasion perpendicular? Perhaps even just determining movement by comparing the patient’s profile contours with traditional beauty standards is a legitimate tactic for surgeons (3mm bone movement = 1mm soft tissue movement). If so, I’m starting to see why surgeons use tools like Dolphin to determine movement with there being so many variables to juggle.

Anyway, at this point I’m honestly not sure the effort involved asking this question (let alone answering it) is worth the inconsequential impact it’ll have on my surgical outcome, I was almost just exploring it for the sake of curiosity. I’m not trying to flood the board with nonsense (too late I suppose), but I figured I’d just offer one last take on what I was originally trying to convey!

The mandible is wider in the back than in the front for everybody. As the surgeon advances the mandible relative to the maxilla, a wider part of the mandible will end up opposite of a narrower part of the maxilla (assuming your mandible and maxilla match up width wise where they are now). You will either need dental compensation (i.e. tilting upper jaw teeth towards your cheek) to give width or an osteotomy. An osteotomy is usually preferable to dental compensation.

Thanks again for the follow-up notrain, and I’m sorry about the delay responding.

Once again, that makes perfect sense, and I’m kicking myself for not seeing it. One of these days I’ll stop being surprised by these things!

[kavan]

Your questions are difficult for me to address as asked because they are predicated on implicit assumptions where I have to figure out or second guess the implicit or faulty assumption behind the question. From that arises a type of over intellectualization; mechinations where you ponder and postulate possibilities of what things could mean.

As to geometry, I have no doubt you would be able to solve a basic geometry problem if presented as a geometry problem or that you would recognize the basic concept once it was revealed to you. But what's needed is more of a connection to geometry so you question or take into account what your assumptions are.

For example, your first assumption was that there was just 'A lefort'.
Next one was spring boarding off of Sanjay's question where his implicit assumption was that the angle of something conveyed information about the 'size' of something.

Presently it seems you could be assuming cephalometric studies are limited to the  S,N, A and B points?

OK, I won't try to second guess what assumptions you have, I'll just tell you this:

You have bi max protrusion. What's protrusive is how the front teeth angle out. But BOTH jaws are RETRUSIVE underdeveloped. HOW retrusive the jaws are relative to a norm has NOTHING to do with the N point. Other points are looked at where LINES are connected from those points (just like in geometry) where Lines have a linear distance that is measured in distance units.

The LINE from points Co-A (with its measure in distance units) is measure of upper jaw retrusion or protrusion. The Line from points; Co-Gn is measure of lower jaw retrusion or protrusion.

So, in terms of 'underdevelopment' or 'size' or something that can be measured in DISTANCE UNITS (as opposed to an angle), BOTH your upper and lower jaw are RETRUSIVE relative to a distance norm. That's a case where addressing BOTH jaws (double jaw surgery) would be needed to maximize the aesthetic outcome. For the bi-max protrusion of the upper teeth, a pre-molar is plucked so they can push things backwards so they can later push the upper jaw forward. The posterior downgraft kind of rotates the front teeth in a better position so they don't look 'flat' from pushing them backwards.

I've given a HINT here as to where to look for the linear measures that tell you both of your jaws are retrusive.

Anyway, that all resolves to what Gunson can do and not what you will be getting from the other guy.

[emanresu]

Your questions are difficult for me to address as asked because they are predicated on implicit assumptions where I have to figure out or second guess the implicit or faulty assumption behind the question. From that arises a type of over intellectualization; mechinations where you ponder and postulate possibilities of what things could mean.

As to geometry, I have no doubt you would be able to solve a basic geometry problem if presented as a geometry problem or that you would recognize the basic concept once it was revealed to you. But what's needed is more of a connection to geometry so you question or take into account what your assumptions are.

For example, your first assumption was that there was just 'A lefort'.
Next one was spring boarding off of Sanjay's question where his implicit assumption was that the angle of something conveyed information about the 'size' of something.

Presently it seems you could be assuming cephalometric studies are limited to the  S,N, A and B points?

OK, I won't try to second guess what assumptions you have, I'll just tell you this:

You have bi max protrusion. What's protrusive is how the front teeth angle out. But BOTH jaws are RETRUSIVE underdeveloped. HOW retrusive the jaws are relative to a norm has NOTHING to do with the N point. Other points are looked at where LINES are connected from those points (just like in geometry) where Lines have a linear distance that is measured in distance units.

The LINE from points Co-A (with its measure in distance units) is measure of upper jaw retrusion or protrusion. The Line from points; Co-Gn is measure of lower jaw retrusion or protrusion.

So, in terms of 'underdevelopment' or 'size' or something that can be measured in DISTANCE UNITS (as opposed to an angle), BOTH your upper and lower jaw are RETRUSIVE relative to a distance norm. That's a case where addressing BOTH jaws (double jaw surgery) would be needed to maximize the aesthetic outcome. For the bi-max protrusion of the upper teeth, a pre-molar is plucked so they can push things backwards so they can later push the upper jaw forward. The posterior downgraft kind of rotates the front teeth in a better position so they don't look 'flat' from pushing them backwards.

I've given a HINT here as to where to look for the linear measures that tell you both of your jaws are retrusive.

Anyway, that all resolves to what Gunson can do and not what you will be getting from the other guy.

I’m about to leave town for a few days (I'm in the process of moving) so I’m sorry that this post is a little more terse than I’d like it to be, but I wanted to at least respond before leaving.

kavan, you are absolutely right, I need to develop a better foundational understanding of the topic instead of driving myself (and others) crazy by trying to pre-emptively “figure it out”. When I get back I will begin looking into reading material on cephalometry/cephalometric analyses.

I think the reason I was obsessed with the points S, N, A, and B (and Pg, but I never mentioned it) is because I assumed those points dictated the curvature/convexity of the face’s profile, and I basically thought the high SNA (at least in my case) showed point A was already “forward enough” comparatively (I’m now being to realize how this is wrong… for several reasons).

Also thank you for your explanation regarding the protrusion being related to the angle of the front teeth (as I thought it was in reference to the upper jaw itself) as well as of Co-A and Co-Gn, which are the variables that it seems SNA was mostly being confused for.

And finally, kavan, thank you so much again for your help, and I’m sorry I couldn’t have come into this discussion more prepared. If in the future I have a question, I will try my best to ensure it is appropriate and informed.

Thanks again, I really do appreciate it.

[kavan]

I’m about to leave town for a few days (I'm in the process of moving) so I’m sorry that this post is a little more terse than I’d like it to be, but I wanted to at least respond before leaving.

kavan, you are absolutely right, I need to develop a better foundational understanding of the topic instead of driving myself (and others) crazy by trying to pre-emptively “figure it out”. When I get back I will begin looking into reading material on cephalometry/cephalometric analyses.

I think the reason I was obsessed with the points S, N, A, and B (and Pg, but I never mentioned it) is because I assumed those points dictated the curvature/convexity of the face’s profile, and I basically thought the high SNA (at least in my case) showed point A was already “forward enough” comparatively (I’m now being to realize how this is wrong… for several reasons).

Also thank you for your explanation regarding the protrusion being related to the angle of the front teeth (as I thought it was in reference to the upper jaw itself) as well as of Co-A and Co-Gn, which are the variables that it seems SNA was mostly being confused for.

And finally, kavan, thank you so much again for your help, and I’m sorry I couldn’t have come into this discussion more prepared. If in the future I have a question, I will try my best to ensure it is appropriate and informed.

Thanks again, I really do appreciate it.

Thanxx emanresu. Happy to hear you are ok with my style of conveying the info. Yes, for the ceph points, there are many of them. When it's a matter of connecting 2 points for a LINE, it's like geometry where since it's a line, it will have a linear unit measure. But when points are used to define angles, like in geometry, angles don't tell you about the size of something. So, if you were looking at your ceph analysis; the one with all the measures on it, you would be looking at things with millimeter measures and eventually you would find the one s with co-A and co-gn which would tell you that BOTH jaws were too retrusive.

Your photo set also shows an illustration that I think Gunson showed you about the angulation of the upper front teeth. that's bi max protrusion and they just can't push them back without plucking a pre-molar. But the only reason, you would want to push them back would be so you COULD move the maxilla forward and it's the posterior down graft that tilts them up and outward somewhat so they don't look 'flat' from the braces.

Anyway, I already mentioned that in terms of AESTHETICS, Gunson's plan was the preferable one IMO. Maybe tell him you can't afford him and ask if he has suggestions for other docs who can carry out his plans.