Recent Posts

Pages: [1] 2 3 ... 10
1
Functional Surgery Questions / Improved nasal breathing through downgraft
« Last post by jawguy14 on Today at 07:09:00 AM »
I wanted to ask what you guys think about the following plan:

I think that I will do a DJS directly, with CCW and a posterior downgraft. A relatively large rotation should be made, with 7mm downgraft so that around 14 degrees rotation is achieved.

I have problems with both, the nasal cavity and the upper airway, which are both too narrow/small. In my unterstanding, the DJS solves both of these Problems due to the downgraft.

Because as I understand it, downgrafting makes the nasal passage longer (i.e. unlike MSE, where the nasal passage becomes wider). Whether wider or longer, in both cases the nasal cavity becomes larger, which I don't think makes any difference.

But since there is no downgrafting in the anterior part, it is almost like a transition from front to back, so that the enlargement of the nasal cavity towards the posterior part of the maxilla is more significant, the further back it is. So it's not a proportional prolongation, the average downgraft (in the example of 7mm posterior downgraft) would be 3.5mm.

Many palate expanders also achieve expansion of around 6, 7, 8mm. But with the palate expansion, it is also not the case that the nasal passage expands completely proportional. It expands more in the lower area (near the nose floor) compared to the area at the top, which is already between the eye sockets. Because not the entire skull is divided down the middle, only the palate is divided (expanded).

In my eyes, an average expansion of 7mm would be similar effective as the 7mm posterior downgraft.

What do you think about this plan. Do you think, that 7mm downgraft would have a similar impact as 7mm expansion?
2
Functional Surgery Questions / Re: SARPE while MMA for better breathing
« Last post by jawguy14 on Today at 02:51:45 AM »
I made the text that extensive because I tried to convey my thought process in as much detail as possible.

To put it more simple: What are the odds that palate expansion (via a expander device) will impact the nasal cavity if expansion is performed shortly after DJS with CCW and posterior downgraft. Regarding the stability of the area, where the LF1 took place and the skull and the maxilla are now connected to the additional bone of the downgrafting.
3
Aesthetics / Re: Why such little extra tooth show? Anterior downgrafting
« Last post by SV123 on Today at 02:42:18 AM »
Just to clarify, these are the movements I am getting:


(Roughly) 4.5mm LF1

10.5mm Pognonion advancment

10.5mm Posterior downgrafting

6.8mm Anterior downgrafting


Despite this, only a total of 3.5mm of extra tooth show. Not saying that I need any more, but am wondering as to how this is possible despite the large anterior downgrafting
4
Aesthetics / Why such little extra tooth show? Anterior downgrafting
« Last post by SV123 on May 27, 2024, 10:36:13 PM »
Hi,

So I have SFS and am getting bimax in a couple of weeks. I have attached a picture of myself and the surgeon's plan.

My question is, why am I only getting an extra 2.5mm of tooth show from the 6.8mm anterior downgrafting? Does the 10.5mm posterior downgrafting counter act the tooth show to some degree?


Thanks
5
Aesthetics / Re: Opinions on my plan
« Last post by kavan on May 27, 2024, 06:53:50 PM »
Yes. CCW rotates the triangle on a fixed point and all the other points and or line orientations rotate/change position in accordance.  Linear advancement is a term they use to convey no rotations and only the advancement of the entire triangle along the directional path of line AB (or BA since it's going forward to point A).

In addition to a triangle being rotated, things can be moved forward along the orientation path of the rotated lines. A rotation is a separate displacement operation than an advancement over a line. An advancement of a point over the path of a line is basically a 'translation' of that point. The path of the line is extrapolated further out and a point moved along that path gets displaced further out. CCW ALONE does not do that. Displacing a point along the path of a line is the advancement.

CCW is not performed alone. It's a geometrical operation that allows the surgeon to advance both the maxilla and the mandible along a better line of orientation. However, in some cases, the ANS point or A point of the triangle can stay put if a large advancement of the lower jaw is not needed. But still, the surgeon needs to perform a BSSO along with the rotation.

Some BACKGROUND in GEOMETRICAL relationships needs to be under belt to relate to the concept of rotating a triangle and also moving landmark points along altered lines orientations. It is NOT something I will discuss in terms of 'chimp lip'.

Basically, what the surgeon is doing is CHANGING the TRIANGLE of the maxillary mandibular complex via rotating it and selecting which lines within it should be increased/elongated and by how much. The goal of the change is toward a better aesthetic balance, a better upper jaw to lower jaw line up. He's got a computer program to rotate the MM complex and from there, he can look at how much to advance the maxilla and mandible with reference to orientation of lines changed by the rotation. The program will show the allowable displacements of the upper and lower jaw like how much they can move each jaw 'forward' along the new orientation lines and still be within a norm and to effect good aesthetic balance. For every 'x' the maxilla is moved 'forward' (along the changed line of its orientation), the mandible will move 'y' amount 'forward along its changed line of orientation. The advancements of both are INTERRELATED or a function of each other. For example, for every mm he moves the maxilla forward on the displacement program, it will show the corresponding increase the mandible can be advanced. The program is used to manipulate a start point triangle in such a way where the end point construct of an altered triangle is also within the venue of a better aesthetic balance. THAT is what your surgeon has done in the diagram/s he showed you. That can be said in the absence of elaborations on geometrical relationships

I don't want to belabor this any further because it all boils down to simply LOOKING AT, observing, what the displacement proposal SHOWS you.  AT very LEAST you should have the conceptual abilities to observe that nothing about it kicks up a monkey muzzle contour, nothing about the upper teeth flaring out can be seen and nothing about the jaw advancement shows disproportion with the rest of the scull. Your anxiety/fears precludes you from the very salient ability you are expected to have when getting a proposal from a surgeon which is to look at the damn thing and decide whether or not you like the PLAN. You like the new contour or you don't.

As to the OTHER persons plan vs the outcome and what OTHER people said about it on a forum, that is neither here nor there. What I observe is that her outcome is in accordance to the displacement proposal. That is to say the her displacement diagram of scull is consistent with her outcome. The displacement proposal was predictive enough for her to decide whether or not she liked it. I would assume she had ample conceptual/perceptual abilities to decide whether or not the proposed bone structure changes would be to her liking as to make a decision.

In closing, what ever decision you make an with what ever abilities or worries you are using to make one, I wish you the best of LUCK. But I need to close this back and forth due to time constraints.





6
Aesthetics / Re: Opinions on my plan
« Last post by Dex1816 on May 27, 2024, 04:31:17 PM »
Quote from: kavan on May 27, 2024, 02:56:56 PM
ETA: If the depiction doesn't show the upper lip angling outward and the teeth don't angle outward in the bone model, no assumption can be made that the teeth would angle outward with a smile given that the orientation of the teeth support the upper lip.

What I meant by the possibility of my teeth coming too far forward wasn't referring to an angulation (a jutting, 'goofy' look). I mean the relative position of the entire occlusal unit as it relates to the rest of the face. For example, I have linked a picture below of Brad Pitt -- someone considered to have excellent facial aesthetics -- smiling. From what I can tell, his incisors align to the established attractive norm at the nasion.

Should his occlusal complex come out as far as mine are predicted to with an 11mm advancement (up to the tip of the nose bone), I would assume him to not be as attractive and to lose a great degree of facial harmony. Again, I cannot directly compare my own predicted outcome to other people, but it is established that the most attractive people have cephalometric commonalities, and it would seem to me there is at least some degree of objectivity involved, to which end you would want to be as close to as possible. This is microcosmic of my overall concern.

Quote
ETA: If the bone model SHOWS you both the jaw advancement and the rest of the scull with it, no assumption can be made that it's out of proportion with the rest of the scull.

I guess I can take this as a rebuttal to my concerns outlined just above, then?
7
Aesthetics / Re: Opinions on my plan
« Last post by Dex1816 on May 27, 2024, 04:04:29 PM »
This was a very sobering post, Kavan, and your explanations of CCWr via demonstration with the triangle were very informative -- thank you.

Quote from: kavan on May 27, 2024, 02:56:56 PM
Enclosed is a diagram of a rotated triangle.

So:

. CCWr rotates the triangle on a fixed point. It still ultimately results in forward advancements, but the terminology 'linear advancement' refers to:
. The entire triangle (all points) moving forward as a unit

What I'm still uncertain about is whether or not in a plan like mine, both of these different movement patterns are taking place -- that first the triangle is rotated as much as is favorable, then it is linearly advanced to bring the maxilla to the final planned 11mm (where the rest of the mandibular advancement takes place via genioplasty).

The reason I ask is that I take it only so much advancement can be brought about by the CCWr because eventually, you'll end up at a 0-degree occlusal plane.

Regarding the theoretical problem of chimp lip, if the entire amount of advancement of the upper and lower jaws could be accomplished with CCWr alone (with the rest of the pogonion taken care of by genioplasty), the risk of chimp lip would surely be very small, as the ANS area associated with the upperlip/under nose fullness would rotating downwards. Hopefully I have this understood correctly.

Quote
There is no ABSOLUTE CERTAINTY to be guaranteed here and NO BETTER predictions to be made here than the one you got already. It's inherently a decision made under uncertainty.

What you have expressed regarding the inherent uncertainty involved aligns with what I have been going through in my own head; whatever decision, it ultimately devolves to something of a leap of faith. I cannot verify that the changes I might wish to make to the plan -- being a non-expert -- would translate to a more favorable result, nor can I guarantee that the soft tissue predictions I've been provided are wholly accurate either.

That said, I have been attempting to resolve some of this anxiety by learning about the well-established attractive norms. For example, it is well-established that for the incisors to line up with the soft tissue nasion is considered attractive, so even if I did opt to dial the advancement of the maxilla down to meet this metric, I would hope I would be in a relatively 'safe' position as to have a favorable outcome (i.e to not be under advanced). The same goes for tried and tested criteria like the True Vertical Line. I appreciate your earlier comments that the individual nature of my own situation must take precedence over cookie-cutter values, however.

Having spoken to my surgeon, they are very willing to make changes based the concerns I have about being advanced beyond what I consider aesthetically pleasing, but you're right -- I have to have something of a solid basis for doing so, and it's difficult to know how much is based on fear and objective reality.

For example, I have attached a publicly available before and after from another patient my surgeon operated on. When this was posted on another public forum, many people said the result was excellent, and many also said they thought the person's jaws were now too big and that their upper lip area had become too protrusive (these were large movements of 18mm at the mandible and 8mm at the maxilla, with CCWr, If I recall -- she is around 5 weeks post op in those images).

As I puzzled the images myself, I went back and forth. It is no doubt there is a great improvement overall, but is there also credence to the notion that she may have been more balanced with slightly less advancement? Perhaps. And there in lies the subjective element of all this that I'm never really going to get a definitive answer to.

As you say, I'm not going to get any better prediction than with the displacement models the surgeon can provide, so it may make sense for them to design a 'dialed back' alternative and then compare them to reach the ultimate conclusion. They said we could design two separate plans.

You have expressed this is likely an optimal plan/likely outcome and made well-founded points as to why. I just now have to make a decision on which direction this 'leap of faith' is going to go.
8
Aesthetics / Re: Opinions on my plan
« Last post by kavan on May 27, 2024, 02:56:56 PM »
CCW-r is based on the rotation of a TRIANGLE constructed from points/landmarks on the maxillary mandibular complex. The concept behind it is that when this triangle is ROTATED, the lower vertex of the triangle advances in a forward direction. So, if point A is ANS of maxilla, point B is PNS of maxilla and point C is the outermost chin point (pogonian), the rotation has it that point C is moved forward via the ROTATION and also that the rotation alters the linear path  the maxilla and mandible can be advanced along. A rotation isn't a linear movement in itself but it changes the orientation of the linear paths moved/advanced along just like rotation of triangle ABC changes the orientation of the linear paths within the triangle.

Enclosed is a diagram of a rotated triangle.

Maxfax NOMENCLATURE has it that the term 'linear advancement' is reserved to describe forward advancement of the whole triangle with NO rotation of it. For example for point C to move forward, point A would also need to be moved forward and along the orientation of line/path AB. So, in both examples using a triangle as reference, advancement is always along a linear path. But the term 'linear advancement basically means forward displacement of the whole triangle along what ever inherent orientation line AB of it has. So, if point C of a triangle is to be advanced forward, point A also has to go along with the ride where as with the ROTATION of the triangle, point C gets a free ride and point A can stay where it is (when it's the rotation point).

After the TRIANGLE is ROTATED, in which case the lines that form it are re-oriented, advancement along the changed paths takes place. So, if point C was to be advanced 'a lot', point A would also need to be advanced but not as much as point A.

Now as to FEARS or concerns about displacements made to your Max-Md triangular complex, a fear or undue concern about point A of the triangle advancing 'too much' could result in an outcome of point C not being advanced enough. Conversely, a fear/concern about point C being advanced 'too much' could result in point A not being advanced enough. If the fear is both being advanced 'too much', it could result in under advancement.

The Max-Md triangular complex looks to be in good aesthetic balance. That is what the bony displacement model shows and also what the soft tissue displacement prediction shows. So, you need to think about it in terms of the MM TRIANGLE on which CCW along with the advancements that can go with it is based. Although the displacement proposal, visual thereof doesn't predict ahead of time whether you will like the outcome or not, it's what you have to base your decision on and more reliable than basing your decision on fears. Also, no one here, including my self can give you a better prediction of the outcome than the visual you were given was or predict whether or not you will like what you see in the mirror. So, if you want to make a decision based on fears of this or that extent of advancement being 'too much' or will 'look funny' or won't look as good as the prediction itself --what ever--you can do that if you want (on your own time) and ask the surgeon for LESS advancement based on those fears/concerns. But if you want to make a decision based on fear, you also need to consider 'what if' your decision requesting a change of plan is a faulty one

In closing, you are assuming the predicted outcome is erroneous or could be. There is NO absolute certainty that it is an exact prediction of an outcome, whether or not you will like it even if it is or whether or not you DO like it as it is depicted. IMO, it's an OPTIMAL outcome. But since your fears lead you down a path of 'what if' it is an erroneous prediction or you might not like it even if it's 99% predictive, then your choices resolve to no surgery at all in the event the prediction does not guarantee the outcome it shows or a choice of which direction you would rather err on; under or over advancement. As to 'what if' the prediction of the outcome is in error in some way, there is also the 'what if' your assumption that it is in error in some way is in error.

There is no ABSOLUTE CERTAINTY to be guaranteed here and NO BETTER predictions to be made here than the one you got already. It's inherently a decision made under uncertainty.

ETA: If the depiction doesn't show the upper lip angling outward and the teeth don't angle outward in the bone model, no assumption can be made that the teeth would angle outward with a smile given that the orientation of the teeth support the upper lip.

ETA: If the bone model SHOWS you both the jaw advancement and the rest of the scull with it, no assumption can be made that it's out of proportion with the rest of the scull.
9
Aesthetics / Re: Opinions on my plan
« Last post by Dex1816 on May 27, 2024, 12:41:16 AM »
Quote from: kavan on May 26, 2024, 06:01:23 PM
Linear advancement is a term where there is NO rotation done.  The rotation changes the line of advancement for both jaws. But just because both jaws are advanced along a more favorable 'line' does not make it a thing where maxilla is CCW and the mandible is linear. The ccw done to the maxilla is such that the mandible is also rotated along with it.  If you want to discuss horror stories of chimp lip risks, discuss them with those who relayed them to you. You asked for opinions on your PLAN. So, no more engaging me in opinions about what ever horror stories you read from who knows where.

Quote
Excuse me but I didn't offer to opine on plans of other people you gleaned your fears from that I can't see. So, don't expect me to opine on something that is not a PLAN I can SEE. Hows about you put up a post in the emotional support section asking for 'OPINIONS ABOUT MY FEARS' if that's what you need validated.  Again, I am responding to a post that reads OPINIONS ABOUT MY PLAN.


Those are fair points, I apologize for skewing the topic in that direction when I asked for help with my own specific take.

As I understand what you've written: CCWr denotes the advancement of both jaws. I take it, then, looking at my own plan, that after such a rotation has taken place, the mandible is then moved even further forward in a linear direction to achieve the rest of the large movement (along with the genioplasty, of course), as presumably CCWr alone couldn't amount to 23mm of advancement. In this way, as the mandible 'went along for the ride' during the rotation, the opposite would be true during the portion of the operation where the mandible was further advanced -- that the maxilla would also be advanced in a linear fashion after the portion of the operation where the whole complex was rotated. Is this correct?


Quote
The nasion norm would apply more to someone who doesn't have a hook like stick out to the nose bone. I explained why the surgeon made that aesthetic judgement call and he gave you  predictive visuals to refer to.

I have attached an image of my current x-ray with another filter. I take it where I've drawn the blue arrow is what you mean by 'hook like stick out'?

I can see how advancing everything to such a point would have this favorable change at the nose, my concern is that it would be at the expense of something else. For example, to have your jaws that far forward from the nasion, wouldn't one need appropriate forward growth in all other areas to match it and have it look normal? (cheek bones, brow ridge, etc).

On the soft tissue plan, it looks good, but I would worry that when I smile, my teeth would look like they jutted forward in an uncanny manner far past the rest of my face.

The surgeon did also said I have a hanging columella, which I assume is due to a lack of support under the nose.

10
Aesthetics / Re: Opinions on my plan
« Last post by kavan on May 26, 2024, 06:01:23 PM »
Quote from: Dex1816 on May 26, 2024, 04:45:39 PM
If I understand what you've said: chimp lip mostly occurs when only linear advancement is used and no CCWr.

When CCWr is used, is linear advancement also employed? or does the CCWr replace the need for linear advancement? I cannot really tell from my plan. If the former is true, isn't there still a risk of chimp lip given that a linear movement is still taking place? Not necessarily relating this to my plan, just interested.

Linear advancement is a term where there is NO rotation done.  The rotation changes the line of advancement for both jaws. But just because both jaws are advanced along a more favorable 'line' does not make it a thing where maxilla is CCW and the mandible is linear. The ccw done to the maxilla is such that the mandible is also rotated along with it.  If you want to discuss horror stories of chimp lip risks, discuss them with those who relayed them to you. You asked for opinions on your PLAN. So, no more engaging me in opinions about what ever horror stories you read from who knows where.

Quote from: Dex1816 on May 26, 2024, 04:45:39 PM
I agree I've gotten too in my head about what are ultimately layperson's interpretations that cannot hold a candle to the calculations of a surgeon, and that what I've heard is clearly not a wholly accurate representation of reality.

To answer your question, nothing about the proposed plan indicates chimp lip, of course. My fears are related to its accuracy regarding those soft tissue changes; surely anyone who has suffered from chimp lip has also gotten a highly sophisticated 3D plan, that presumably did not show these aesthetic problems before surgery as then they assuredly would've been altered.

While as you say, this problem seems characteristic with insurance sleep apnea cases, what about the people who go to top surgeons like Alfaro and Alfi and report to coming out over advanced/with protrusive lips? Shouldn't their 3D plans have shown this would be the case?

Excuse me but I didn't offer to opine on plans of other people you gleaned your fears from that I can't see. So, don't expect me to opine on something that is not a PLAN I can SEE. Hows about you put up a post in the emotional support section asking for 'OPINIONS ABOUT MY FEARS' if that's what you need validated.  Again, I am responding to a post that reads OPINIONS ABOUT MY PLAN.

Quote from: Dex1816 on May 26, 2024, 04:45:39 PM
I see, that aesthetic choice makes sense. If the attractive norm is to have the maxilla at the nasion, though, is there not a risk that I'll look a little strange with my teeth way out there?

The nasion norm would apply more to someone who doesn't have a hook like stick out to the nose bone. I explained why the surgeon made that aesthetic judgement call and he gave you  predictive visuals to refer to.

Quote from: Dex1816 on May 26, 2024, 04:45:39 PM
Thank you for taking the time to write such a detailed reply. It has been very reassuring despite the fact I clearly still have a lot to learn about this procedure.

You're welcome but if I had known ahead that all of this advice would be dominated by your need to have fears addressed found who knows where, I would have passed on it.
Pages: [1] 2 3 ... 10