Weak and recessed lower jaw-health problems.

[Dutcherhatcher]

NO. You have ONE option and that is to revisit concepts in elementary geometry because if you don't understand the very fundamental relationship of rotating a TRIANGLE and how the parts of it displace as a function of the direction of the rotation and a fixed rotation point you will have NO BASIS to relate anything they do in maxfax. Nor will I address questions that reflect a a lack of that type of basis.  Your questions reflect you lack this fundamental basis.

'Post bimax's' answers reflect he has good grounding in basic geometry which is what you need for things to be more self explanatory.

Hey i went over the educational section. Focusing for example on Arnett FAB planning and Antipov presentation, and the occlusion plane paper you linked. i understand better how to approach my problem and how does the CCW comes into effect.
We need to have space for the mandible to come forward>we elongate the back of the maxilla(make a cut, lower it and fill it with bone) >that in turns rotate the entire structure, giving the surgeon the option to advance the mandible in the new structure> the occlusion planes flattens>the lip\upper maxila area comes a bit forward.



cavats: stability of the joints might be a problem
Too much flatting might happen.


One thing i did not find any refrence for is the "anchorage" point of the rotation, either at the incisiors or the ANS. How does that come into effect? Can you direct me to a paper that explains that point?

What do you think about doing CCW in my case where i have one sided TMJ? I understand Arnett and co believe it is stable, but it still scares me that a large body of current day surgeons believes it is unstable, not that i hace another option if i want to breathe air like a normal person.


I understand now why CCW without BSSO makes no sense and what you meant

The philtrum area advances simply because of the rotation effect

Antipov also talks about Occlusiom plane being ideal at around 8. How can i know my occlusion plane now?


Anything else you think i should be focused if i continue now with A/R, including self education etc.

In the attached picture, i think is the best way to show the rotation, but still could not find any refernce to the ANS vs incisiors refernce point. Do you mean posterior vs anterior impaction

[Post bimax]

Refer to figure 1 of the most recent post in the Education section

[Dutcherhatcher]

So, I think I have an even better understanding now.
Sadly in this section
(https://pocketdentistry.com/rotation-of-the-occlusal-plane/)
they only refer clockwise rotation at certain points, but I still got the gist of it.
A case like mine should have advancement at the ans point, since I do want the Ans to not go backward, as well as provide better lip support. I assume rotation around the incisor is done with bimax protrusion cases?

TABLE 12-5
Counterclockwise Rotation of the Maxillomandibular Complex around the ANS Point *
Hard-Tissue Changes   Soft-Tissue Changes
OP angle   Decrease   Subnasale   No change
Maxillary incisor tip   Advance   Upper lip support   Increase
Pog position   Advance   Facial convexity (contour)   Decrease
Maxillary incisor angle   Increase   Mandibular prominence   Increase
Maxilla at ANS   No change   Paranasal fullness   No change
MP angle   Decrease   Nasolabial angle   Decrease
Posterior maxillary height   Increase   Anterior facial height   No change
Chin throat length   Increase



Ok after paying 50$ and getting the full page.


“Rotation of the maxillomandibular complex is considered only in cases in which an acceptable result cannot be achieved by conventional treatment planning methods. A conventional visual treatment objective should always be developed for every patient before alternative treatment designs are contemplated.”

We tried it in my case and failed, there is no option to bring the mandible forward

“ There are scant data in the literature regarding skeletal stability after clockwise and counterclockwise rotation of the jaws. Poor skeletal stability after the counterclockwise rotation of the mandible has been reported by Schendel and Epker. They relate poor stability to the increase in posterior facial height and the associated increase in length of the pterygomasseteric musculature. Proffit, Turvey, and Phillips found that surgical decrease of the anterior facial height by counterclockwise rotation of the mandible (i.e., closure of anterior open bite malocclusions) would jeopardize the stability of results. Their results, when treating patients with vertical maxillary excess and mandibular anteroposterior deficiency (with or without open bite) by means of superior repositioning of the maxilla and mandibular advancement, proved to be more stable, with 60% of cases judged to have excellent clinical results. Moreover, the use of rigid fixation in these cases further improved stability, with 90% of these cases being judged to have excellent clinical outcomes. Chemello, Wolford, and Buschang reported stable results after both clockwise and counterclockwise rotation of the maxillomandibular complex. They stipulate that this is made possible by proper preoperative orthodontic treatment, proper execution of surgery, and the presence of healthy temporomandibular joints. Rosen reported similar results and made certain surgical recommendations to improve the stability. Reports in the literature identify three factors that may influence stability after orthognathic surgical procedures.”

This is worrying, but it’s not like I have another option. I don’t think there are more people out there with better skills than A/R. I guess this is my main problem, since I do suffer from TMJ on my right side. I know Wolford like to replace the joint, but what about the rest


Anything else I am missing Kevan?

[kavan]

Let's say I was testing capacity students had to recognize elementary geometric relationships based on ROTATING a triangle and I found some random photo on which I CONSTRUCTED the red triangle of ABC. But NO student was expected to know ANYTHING about maxfax. Instead, just conceptual things having to do with triangles.

Let's say that on the capacity test, ONLY the red triangle ABC was there on the photo. Not the green one.

Let's say, the green one on the photo was drawn ONLY by the students who passed the capacity test. 

Here is what would be asked to determine capacity:

'Rotate Triangle ABC 10 degrees so that C is displaced forward to C' and B is displaced downward to B'. Choose A as the fixation point and use green.'

(The capacity test did not say which direction to choose; CCW or CW because part of the capacity being tested was ability to to recognize which direction to choose to answer the question.)

QUESTION: What would the people who could pass the very basic capacity test need some basis in to show the answer to the question?

a: Geometrical relationships

b: Maxillo-facial surgery.

Answer: 'a'.

QUESTION: Which people on JSF entertaining maxfax surgery will become MOST confused about a subject having to do with points, lines, angles, planes and rotations.

a: Those who have a basis of elementary geometry  to 'relate to'.

b: Those who don't

Answer: 'b'

QUESTION: Given that the angles and relative distances of the 'legs' of the triangle are measured out and leg AC is LONGER than leg AB and without measuring or calculating the distance of BB' or CC', which people would 'intuitively' know that distance CC' is going to be MORE than distance BB'.

a: Those who go on multiple consults

b: Those who see the relationship that triangles; ABB' and ACC' both are 10 degrees at vertex A
and both are isosceles triangles (because AB=AB' in one and AC=AC' in the other) but since AC is LONGER than AB, the BASE of triangle ACC' will be longer than the base of triangle ABB'.

Answer: 'b'

MORAL OF STORY: The (hypothetical) student who could show the green triangle AB'C' to demonstrate a 10 degree rotation of the red triangle; ABC and would know to choose direction CCW such that B' was found vertically lower, C' was found advanced forward and A was fixation point to show that, would have NO PROBLEM relating the distance; BB' to a posterior downgraft and the also relating the horizontal displacement distance from C to C' as being a direct consequence of the vertical displacement of B to B' from the CCW rotation. They also would be able to rotate ANY triangle in either direction from any fixed point and observe the displacements to the triangle. People, who would not be able to do something like that will have a hard time understanding how some of these maxfax relationships work BECAUSE they have limited basis to relate it BACK to.

Diagram enclosed with this post.

[Dutcherhatcher]

Let's say I was testing capacity students had to recognize elementary geometric relationships based on ROTATING a triangle and I found some random photo on which I CONSTRUCTED the red triangle of ABC. But NO student was expected to know ANYTHING about maxfax. Instead, just conceptual things having to do with triangles.

Let's say that on the capacity test, ONLY the red triangle ABC was there on the photo. Not the green one.

Let's say, the green one on the photo was drawn ONLY by the students who passed the capacity test. 

Here is what would be asked to determine capacity:

'Rotate Triangle ABC 10 degrees so that C is displaced forward to C' and B is displaced downward to B'. Choose A as the fixation point and use green.'

(The capacity test did not say which direction to choose; CCW or CW because part of the capacity being tested was ability to to recognize which direction to choose to answer the question.)

QUESTION: What would the people who could pass the very basic capacity test need some basis in to show the answer to the question?

a: Geometrical relationships

b: Maxillo-facial surgery.

Answer: 'a'.

QUESTION: Which people on JSF entertaining maxfax surgery will become MOST confused about a subject having to do with points, lines, angles, planes and rotations.

a: Those who have a basis of elementary geometry  to 'relate to'.

b: Those who don't

Answer: 'b'

QUESTION: Given that the angles and relative distances of the 'legs' of the triangle are measured out and leg AC is LONGER than leg AB and without measuring or calculating the distance of BB' or CC', which people would 'intuitively' know that distance CC' is going to be MORE than distance BB'.

a: Those who go on multiple consults

b: Those who see the relationship that triangles; ABB' and ACC' both are 10 degrees at vertex A
and both are isosceles triangles (because AB=AB' in one and AC=AC' in the other) but since AC is LONGER than AB, the BASE of triangle ACC' will be longer than the base of triangle ABB'.

Answer: 'b'

MORAL OF STORY: The (hypothetical) student who could show the green triangle AB'C' to demonstrate a 10 degree rotation of the red triangle; ABC and would know to choose direction CCW such that B' was found vertically lower, C' was found advanced forward and A was fixation point to show that, would have NO PROBLEM relating the distance; BB' to a posterior downgraft and the also relating the horizontal displacement distance from C to C' as being a direct consequence of the vertical displacement of B to B' from the CCW rotation. They also would be able to rotate ANY triangle in either direction from any fixed point and observe the displacements to the triangle. People, who would not be able to do something like that will have a hard time understanding how some of these maxfax relationships work BECAUSE they have limited basis to relate it BACK to.

Diagram enclosed with this post.

Thank you very much Kavan. I believe i understand it much better

You got a very nice skeletal model there. I am sure the guy is very handsome

[kavan]

Thank you very much Kavan. I believe i understand it much better

You got a very nice skeletal model there. I am sure the guy is very handsome

   Totally random photo I found on the internet.

[kavan]

Hey i went over the educational section. Focusing for example on Arnett FAB planning and Antipov presentation, .....

I just wanted you to look at the link where I put the triangles.

[april]

One thing i did not find any refrence for is the "anchorage" point of the rotation, either at the incisiors or the ANS. How does that come into effect? Can you direct me to a paper that explains that point?

I assume rotation around the incisor is done with bimax protrusion cases?

Its confusing, but when they do the practical planning, the incisor tips are often used as the point of rotation. I saw this on screen during my own consult with G (his plan for me was a very large posterior downgraft/CCW). He played around with the rotation (increasing and decreasing) and I could see the rotation was happening around the incisors, not ANS. It didn't really match with Reyneke's triangle concepts, where one would expect that a posterior downgraft would rotate around an ANS point.

I saw that in the below article it does say Arnett Gunson plan surgery with the incisor point as the point of rotation. It seems the planning/workflow seems to be to basically get everything correct horizontally and vertically, and then as a final step rotate the occlusal plane around incisor tips as needed.

Esthetic cephalometric planning for orthognathic surgery involves seven substeps:
1. Maxillary incisor angulation to the maxillary occlusal plane (orthodontic tooth movement)
2. Mandibular incisor angulation to the mandibular occlusal plane (orthodontic tooth movement)
3. Overbite correction (may be obtained with substeps 1 and 2)
4. Overjet correction (may be obtained with substeps 1 and 2)
5. Esthetic anteroposterior and vertical maxillary incisor positioning (may be obtained with substeps 1 and 2 or maxillary surgery)
6. Occlusal plane manipulation to produce esthetic anteroposterior positions of the nasal base and chin (requires two-jaw surgery)
7. Chin osteotomy when necessary (only after steps 1-6)

Substeps 1 and 2 have been described above under orthodontic incisor positioning; the normal ranges for the upper and lower incisors to the upper and lower occlusal planes are 54-60° and 61-68°, respectively. If orthodontic completion of these substeps corrects the overjet and overbite and provides acceptable facial esthetics, and if a normal airway exists, then surgery is not necessary.

If an overjet abnormality still exists after substeps 1 and 2, treatment proceeds to substeps 3 and 4. In these substeps, the occlusion is positioned in a Class I relationship, and the overbite and overjet are corrected by surgery of the lower, upper, or both jaws.

Substep 5 is utilized when the face is still imbalanced or the airway is still compromised. This maxillary surgery positions the maxillary incisors anteroposteriorly and vertically as indicated by facial needs, providing ideal anteroposterior support of the lip with 3-4mm of incisor exposed beneath the lip.

Substep 6 alters the maxillary and mandibular occlusal planes, based on esthetic and airway needs. The maxillary incisor position, as set in substep 5, acts as the center of rotation for the occlusal plane. The posterior occlusal plane is moved either superiorly or inferiorly, depending on nasal base and chin projection needs. When ideal esthetics are achieved, the maxillary occlusal plane is usually between 93° and 98° to the true vertical line, which is a line perpendicular to natural head position as described by Arnett and colleagues.3 Flattening the occlusal plane into the normal range maximizes chin projection without the need for substantial, unattractive chin augmentation (Fig. 3). Additionally, a normal occlusal plane prevents the excessive nasal base fullness that can occur when the occlusal plane is steepened with traditional posterior maxillary impaction.

From http://jawsurgeryforums.com/index.php/topic,7881.0.html

[kavan]

Its confusing, but when they do the practical planning, the incisor tips are often used as the point of rotation. I saw this on screen during my own consult with G (his plan for me was a very large posterior downgraft/CCW). He played around with the rotation (increasing and decreasing) and I could see the rotation was happening around the incisors, not ANS. It didn't really match with Reyneke's triangle concepts, where one would expect that a posterior downgraft would rotate around an ANS point.

I saw that in the below article it does say Arnett Gunson plan surgery with the incisor point as the point of rotation. It seems the planning/workflow seems to be to basically get everything correct horizontally and vertically, and then as a final step rotate the occlusal plane around incisor tips as needed.
From http://jawsurgeryforums.com/index.php/topic,7881.0.html

What matters is that people wanting to know about rotations, any of them understand the fundamental geometric concepts involved with rotating triangles around a point, ANY point.

[Post bimax]

A useful mental model for visualizing rotations IMO is to ‘stick a pin’ in the axis and then mentally rotate and think about what that means in terms of surgical procedures.

[kavan]

A useful mental model for visualizing rotations IMO is to ‘stick a pin’ in the axis and then mentally rotate and think about what that means in terms of surgical procedures.

YES. But we call this the POINT of rotation when it involves a triangle.  I just corralled in a friends kid, (in 4th grade)  gave him a cut out of a triangle, asked him to trace it. Then ask him to hold a selected point down (a vertex like the one I gave in my example), rotate the triangle, trace that and tell me something about where the other vertices went. The KID was able to observe and answer the question correctly.  Not saying that ALL kids would be able to get it right though.

[Dutcherhatcher]

Guys a few questions i have.
How terrible would it be if my maxilla is advanced by 2 mm as compared to nothing? Is it avoidable?
My occlusal plane right now is 5 degrees. Is it not problematic?
How does the occlusal plane translate into teeth show?

[Dutcherhatcher]

Just spoke with my original surgeon. He was shocked that the ortho said she will only be able to produce 5 mm result. As well as another year of treatment. He said he is still 100% sure he will be able to get 8-9 mm of jaw movement along with 4/5 mm of genio at a much shorter time. He will give me an update in the next few days on how to proceed.

Why am I the one who is suppose to tell him? Are they not suppose to communicate between them? What the hell did I get myself into.

[kavan]

Just spoke with my original surgeon. He was shocked that the ortho said she will only be able to produce 5 mm result. As well as another year of treatment. He said he is still 100% sure he will be able to get 8-9 mm of jaw movement along with 4/5 mm of genio at a much shorter time. He will give me an update in the next few days on how to proceed.

Why am I the one who is suppose to tell him? Are they not suppose to communicate between them? What the hell did I get myself into.

Here is a quote of mine from another thread (on the educational section):

...

 ' Absence of treatment plan, when orthodontist and surgeon do not communicate....'

I think that is often the case when patients are in braces (or invasaline) for 'something' and then they go around on multi consults in pursuit of the maxfax part of various treatment proposals where the situation is inherently one where there is no communication between which ever otho they have and the doctors they are consulting with. They are in braces for 'something' and the more consults they go on, the more they get confused and linger longer in indecision. Any treatment plan via braces should be that of the CHOSEN doctor such there is direct communication via him/her and ortho. All treatment plans from any doctor are always contingent on the braces doing what they want them to do.

Also, the operative word in your statement is 'MY', 'my surgeon'. Perhaps, just semantics, but he's not 'your' surgeon unless you've pre-selected him over the others you consulted with.

[april]

Why am I the one who is suppose to tell him? Are they not suppose to communicate between them? What the hell did I get myself into.

You remind me of me. Things felt 'wrong' and I was getting very frustrated with the lack of communication from quite early on in the process, and how I was doing all the work for them. It was a red flag I didn't think to give enough attention to. I would advise you to be careful - if you think it's lack of communication from your ortho specifically, transfer to a new one.