My surgical plan. Thoughts?

[Class2]

Hi everyone,
 
New here. Another stranger's story incoming.

Link with chronological scans: https://docs.google.com/presentation/d/1JWgKXtqSWXIOfA5ymbC2LvcAATQgnsXA

Information

·         34 year old male in Canada, and only choosing a Canadian surgeon due to cost

·         Wisdom teeth removed, no other extractions

·         11-13 years old - braces with elastics

·         Have VME – currently 5mm anterior gingival display, appearance has reduced due to aging, as seen in the photos

·         5mm lip incompetence

·         Currently, 5mm overjet (it is unstable due to my post DNA bite)

·         Very vaulted palate

·         Minor anterior open bite ~0.5mm

·         Daily nasal congestion (not from allergies). Been mouth taping and using nasal dilators for 3 years. Septum is only minimally deviated, probably not clinically significant.

·         31-33 years old DNA treatment; results – bucally tipped molars (mostly upper), potentially stretched alveolar bone, and repositioned mandible within TMJ, as seen in the pre and post cbct

·         Had a posterior tongue tie release and myofunctional therapy

·         31 years old - OSA diagnosis, REM RDI of 30/hr, overall 10 RDI/hr. Use CPAP.
 

Goals

·         Treat OSA

·         Lip seal/no mentalis strain

·         Improve aesthetics (gum show, retrognathia)


Tentative plan

·         MARPE with piezo cuts along the MPS to gain stable transverse expansion and improve nasal breathing. Molars will be upright from DNA damage with aligners or braces. Lower arch will need SFOT to align upper and lower teeth (I only have a thin layer of buccal bone). For reasons too long to list on a jaw surgery forum, I prefer the MARPE with piezo over segmental lefort 1 or SARPE/DOME.


Surgery thoughts

Based off my research, my high occlusal and mandibular planes, desire to avoid extractions to maintain arches, and maximize BSSO advancement, CCWr seems optimal. I do think impaction would be beneficial for autorotation and gum show, however I am looking for a conservative number due to aging/reduced teeth show, and nasal cavity volume reduction. Given this limitation, CCWr via posterior downgrafting would allow for improved OP/MPA beyond that of an impaction alone, while also avoiding lower teeth extractions necessary for linear movements. I do believe my gum show is mostly anterior, so I feel I am not contraindicated for posterior downgrafting (which can exacerbate posterior gum show). I am aware that for many class 2's, a large maxillary advancement with impaction can have undesirable nose aesthetics (even with alar suture), along with that "monkey" look, so for that reason I would be conservative with this advancement. I do not have a chin, so I do think a sliding genioplasty would help with lip competency and aesthetics. Since I do have some excessive overjet in my current position, I can afford some linear advancement too.

Given my thoughts above, I was thinking (I know the numbers would vary, but just want to illustrate my plan):

·         3mm anterior impaction; 1-2mm differential impaction, depending on margin of error with custom guides

·         3-4mm maxillary advancement

·         4-6mm sliding genioplasty

·         X degree downgraft

·         X mm BSSO advancement. I don't know what this number would be after all the other movements. Hopefully 10-14mm at B point.


Questions

·         Since rotation doesn't change the bite relationship, how is the degree of decompensation decided pre-op? My incisors are still proclined as per the photos. I of course want to maintain a dental class 1 post-op.

·         What would be the ideal fixed point for the CCWr in my case, if there was one? If it wasn't for the impaction I would assume it's the ANS, but I am not sure.

·         Is there a preferable material to be used for the downgraft? Autograft seems more favorable over synthetic, but I would love more opinions on this.

·         Is there a certain order that makes more sense in which jaw is operated on first when impaction and downgrafting is involved?

·         Any downsides to downgrafting? As far as I know, it is as stable as impaction which has been well researched.

·         Does this all make sense? Any glaring deficits in my knowledge? I would love to fill in those gaps!

 
I have 2 consults upcoming in May, and will book more if needed. I just want to be as prepared as possible going in. If I can't find a surgeon locally to do these movements, a compromised plan would be a standard linear advancement after decompensation with a small impaction and genio. Downside is potential extractions, smaller bsso/less flattening of the OP, leading to underwhelming aesthetic outcomes and possibly unaddressed SDB.

Thanks for reading!

[GJ]

In general, the lower jaw is put in position first. That's based on models (on an articulator) to know where to put it. Then the upper is moved to match that. Basically a mock surgery. Some surgeons do the opposite, but it's not the modern standard of care. Natural bone is best for the down graft. I'm not sure on decompensation. An ortho should be able to answer that. Your teeth look to be in a pretty good place to me. I'd imagine it'll be minimal.

I think you're on the right track with CCWr and impaction, and to take it light on the impaction. Better to do to little than to much.

[kavan]

Age 22 photo reveals excess gummy smile which is corrected by impaction. Excess length to the frontal aspect of the maxilla can force lower jaw backwards and downwards. Excess length to the back part of the maxilla can do some of that too as in anterior open bite. Your smile in age 33 (doesn't matter if it's pre or post some 'DNA' method) shows you have maxillary excess to both anterior aspect of maxilla and posterior. So, impaction would most likely be to over all maxilla to shorten excess length which would be a combo of anterior and posterior impaction. A combo of both anterior and posterior impaction yields a NET rotation. If more removed from anterior than posterior then net would be CCW-r. Conversely, if more is removed from posterior than anterior then net would be CW-r. Anyway, with an overall impaction, that is NOT a 'downgraft'

 Impaction removes the excess length and often that allows the mandible to swing up and outward for a better profile. Age 23 of mentalis strain stands to be corrected in the process of correcting the gummy smile via impaction given that the surgery allows the jaw to swing upward and outward to reduce the strain. Genioplasty would also assist in that.

With the combined impaction, maxillary and mandible advancement would follow. Although the maxillary impaction alone would not advance the upper jaw, it allows the advancement of the upper jaw along a more favorable orientation. Some of advancement of lower jaw can result from an 'automatic' swinging up and out from the impaction. The other, of course from BSSO advancement.

DISCLOSURE: I have made these general observations solely by looking at some of your photos.When there are photos to observe, I observe in the absence of a posters self assessments and/or questions in the event my observations SOLELY on the photos help the poster adapt what ever questions they have to the observations I've made.

[TWGOAT]

Age 22 photo reveals excess gummy smile which is corrected by impaction. Excess length to the frontal aspect of the maxilla can force lower jaw backwards and downwards. Excess length to the back part of the maxilla can do some of that too as in anterior open bite. Your smile in age 33 (doesn't matter if it's pre or post some 'DNA' method) shows you have maxillary excess to both anterior aspect of maxilla and posterior. So, impaction would most likely be to over all maxilla to shorten excess length which would be a combo of anterior and posterior impaction. A combo of both anterior and posterior impaction yields a NET rotation. If more removed from anterior than posterior then net would be CCW-r. Conversely, if more is removed from posterior than anterior then net would be CW-r. Anyway, with an overall impaction, that is NOT a 'downgraft'

 Impaction removes the excess length and often that allows the mandible to swing up and outward for a better profile. Age 23 of mentalis strain stands to be corrected in the process of correcting the gummy smile via impaction given that the surgery allows the jaw to swing upward and outward to reduce the strain. Genioplasty would also assist in that.

With the combined impaction, maxillary and mandible advancement would follow. Although the maxillary impaction alone would not advance the upper jaw, it allows the advancement of the upper jaw along a more favorable orientation. Some of advancement of lower jaw can result from an 'automatic' swinging up and out from the impaction. The other, of course from BSSO advancement.

DISCLOSURE: I have made these general observations solely by looking at some of your photos.When there are photos to observe, I observe in the absence of a posters self assessments and/or questions in the event my observations SOLELY on the photos help the poster adapt what ever questions they have to the observations I've made.

If it can help OPs case since we have similar profile/smile, I had a consult with a reknowned surgeon last week and i discussed the CCWr rotation aspect with impaction only vs impaction/downgraft vs effect on posterior gummy smile.

He said to achieve enough rotation it's ok to compromise on some posterior gumshow and have a combination of posterior downgraft / anterior impaction.

Anterior impaction only normally can't rotate much unless you impact a lot which reduces nasal cavity volume and soft tissue support.

I was previously quoted 5mm anterior impaction with 3mm posterior impaction by a local surgeon which nets a maximum of 2-3 degree CCW rotation

Here is the drawing based on my ceph, disregard the TJR, it would be BSSO in this case - with approx 4mm impaction, and 3mm downgraft for around 13 deg CCW rotation, around 14mm BSSO, and he said maxillary incisor advancement of around 9mm : https://imgur.com/a/N8O15zm

Here is my previous thread for reference : https://jawsurgeryforums.com/index.php/topic,8442.0.html

I'm also in Canada by the way, will have a follow up consult next week with a local surgeon to show him this plan.

[Class2]

Age 22 photo reveals excess gummy smile which is corrected by impaction. Excess length to the frontal aspect of the maxilla can force lower jaw backwards and downwards. Excess length to the back part of the maxilla can do some of that too as in anterior open bite. Your smile in age 33 (doesn't matter if it's pre or post some 'DNA' method) shows you have maxillary excess to both anterior aspect of maxilla and posterior. So, impaction would most likely be to over all maxilla to shorten excess length which would be a combo of anterior and posterior impaction. A combo of both anterior and posterior impaction yields a NET rotation. If more removed from anterior than posterior then net would be CCW-r. Conversely, if more is removed from posterior than anterior then net would be CW-r. Anyway, with an overall impaction, that is NOT a 'downgraft'

 Impaction removes the excess length and often that allows the mandible to swing up and outward for a better profile. Age 23 of mentalis strain stands to be corrected in the process of correcting the gummy smile via impaction given that the surgery allows the jaw to swing upward and outward to reduce the strain. Genioplasty would also assist in that.

With the combined impaction, maxillary and mandible advancement would follow. Although the maxillary impaction alone would not advance the upper jaw, it allows the advancement of the upper jaw along a more favorable orientation. Some of advancement of lower jaw can result from an 'automatic' swinging up and out from the impaction. The other, of course from BSSO advancement.

DISCLOSURE: I have made these general observations solely by looking at some of your photos.When there are photos to observe, I observe in the absence of a posters self assessments and/or questions in the event my observations SOLELY on the photos help the poster adapt what ever questions they have to the observations I've made.

In general, the lower jaw is put in position first. That's based on models (on an articulator) to know where to put it. Then the upper is moved to match that. Basically a mock surgery. Some surgeons do the opposite, but it's not the modern standard of care. Natural bone is best for the down graft. I'm not sure on decompensation. An ortho should be able to answer that. Your teeth look to be in a pretty good place to me. I'd imagine it'll be minimal.

I think you're on the right track with CCWr and impaction, and to take it light on the impaction. Better to do to little than to much.

Thank you for your responses. I just got back from seeing my first surgeon and I wanted to know what you two or anybody else on the forum thinks.

He explained that for my case, he doesn't feel my mandible is particularly steep/high and that an anterior differential impaction of 3-4mm would result in poor nasal aesthetic outcomes and a flat appearance. We couldn't do a VSP on the spot as it is out sourced, but he did give some preliminary numbers to work with. He feels that a 3mm level impaction with maybe 1mm anterior differential and then bsso and small max adv + 4-6mm sliding genio to follow would be sufficient. Because of my plane he feels downgrafting is also unnecessary (but he is trained to do this).

He explained that when you make the standard lefort 1 cuts at the ANS, because the cut is not horizontal bur rather diagonal, maxillary advancement alone will cause superior movement of the maxilla, and when you add impaction on top of that it can be too much in some cases, especially for the nasal region. He also said that anterior impaction doesn't autorotate the mandible as much as posterior impaction does. I didn't fully comprehend the explanation on this reasoning though.

I asked him about my 5mm lip incompetency and he said the level impaction and if I wanted a V–Y closure (this part I might've confused with something else, there was a lot of information) would help. I have a large beard so hopefully he's not being influenced by that when looking at aesthetics in person lol (it hides most of my recession). Very passionate and friendly surgeon!

This was surprising news as I thought I for sure had a steep mandibular plane, albeit not as bad as others on this forum. I booked an appointment with him and a VSP tech/engineer(?) to go over numbers in more detail. Thoughts? Red flags? Underwhelming numbers? I'm seeing another surgeon in 2 weeks.

[kavan]

IMO, the salient concept here is that your mandible would need to swing up to help close the bite, especially since one of the problems listed in the ceph trace you provided was skeletal open bite which is Anterior Open bite.

Now the mandible CAN auto rotate up with the anterior impaction which could be used to also cut down on the gummy smile one sees in front. But, off course, too much anterior impaction coupled with maxillary advancement can bring on unfavorable aesthetic sequella. So, it does not sound like the doctor precluded anterior impaction (given he relayed some approx. mm measures for it along with some max advancement). It just sounds like he's not going to go all out with it as to depend on that entirely. So far, so good.

Regarding: "Because of my plane he feels that down grafting is unnecessary".

OK, that sounds consistent with what I conveyed in my initial post. The 'plane' being referred to would be the MAXILLARY plane given the context is downgrafting= not needed.

Regarding: "He explained that when you make the standard lefort 1 cuts at the ANS, because the cut is not horizontal bur rather diagonal, maxillary advancement alone will cause superior movement of the maxilla, and when you add impaction on top of that it can be too much in some cases, especially for the nasal region... "

I'm perplexed by the statement that the maxillary CUT and advancement is 'diagonal' in all cases. Perhaps I'm missing something here but to the best of my knowledge, the Lefort 1 max cut is along the PLANE of the maxilla= ANS-PNS orientation. When ANS is higher than PNS, than that would be a cut along a diagonal plane (due to the inherent orientation) and with no rotation, advancement of the maxilla would cause superior movement because movement is on upward diagonal.

Your ceph tracing (and ceph) show your ANS-PNS (maxilla), orientation is aligned HORIZONTALLY. So, I'm a loss to explain why a 'diagonal cut' applies to you. PERHAPS, something got 'lost in the translation' and he is trying to convey to you that with CCW-r of the maxilla--too much of it via anterior impaction--would change the orientation of your maxilla and put it on on an UPWARD DIAGONAL path and advancement along that type of 'vector' would not look good. IF that is what he is meaning to convey, than that is true. 

Regarding: "....He also said that anterior impaction doesn't autorotate the mandible as much as posterior impaction does. I didn't fully comprehend the explanation on this reasoning though."

I'm also perplexed by this statement IF the statement is meant to be universally true in all cases. To the best of my knowledge, it would depend on the extent of the impaction in one place vs. the other and also which one the particular patient needed the most. The salient info is that BOTH can assist in auto-rotating the mandible to swing up and BOTH can DECREASE the INCLINATION of the MPA (mandibular plane angle) whether or not he tells you he doesn't think it's excessively high.

In your case, you CLEARLY have (evidenced by the ceph tracing, the lower face profile and the mention of such) as SKELETAL OPEN BITE which is AOB (anterior open bite). A key factor with that is that the posterior maxilla is TOO LONG and the excess length there FORCES the lower jaw downward into an unfavorable position where said unfavorable position is making the MPA look too STEEP. The mandible can't swing up to help CLOSE the bite when the posterior teeth are oriented too far down. OK. Hence posterior impaction to the back of the maxilla helps to allow the mandible to swing upward. When it does, the BSSO advancement can displace along a LESS STEEP MPA. The BSSO advancement will take the chin along 'for the ride' and of course, the chin can also be displaced to address to address lip incompetence.

As to the 'steep mandibular plane', perhaps this is a matter of semantics (or subterfuge on the part of how the doctor explained things). VISUALLY, you DO have a steep MPA. Why? Because excess length to the posterior maxilla FORCES it into a steep ORIENTATION. However TECHNICALLY you don't have a steep MPA and it just looks that way BECAUSE the EXCESS to the POSTERIOR maxilla is FORCING it into a downwardly steep orientation. Hence POSTERIOR IMPACTION is going to REDUCE the STEEPNESS that is VISUALLY noticible.

His suggestion resolves to combined impaction and is somewhat consistent with what I said in the first place. The fact that I had to make great efforts to 'translate' what he COULD HAVE meant makes me wonder why he didn't 'talk straight'. However, perhaps he had to battle with or otherwise counter some of your own assessments such as implied preference for posterior downgrafting.

[Class2]

IMO, the salient concept here is that your mandible would need to swing up to help close the bite, especially since one of the problems listed in the ceph trace you provided was skeletal open bite which is Anterior Open bite.

Now the mandible CAN auto rotate up with the anterior impaction which could be used to also cut down on the gummy smile one sees in front. But, off course, too much anterior impaction coupled with maxillary advancement can bring on unfavorable aesthetic sequella. So, it does not sound like the doctor precluded anterior impaction (given he relayed some approx. mm measures for it along with some max advancement). It just sounds like he's not going to go all out with it as to depend on that entirely. So far, so good.

Regarding: "Because of my plane he feels that down grafting is unnecessary".

OK, that sounds consistent with what I conveyed in my initial post. The 'plane' being referred to would be the MAXILLARY plane given the context is downgrafting= not needed.

Regarding: "He explained that when you make the standard lefort 1 cuts at the ANS, because the cut is not horizontal bur rather diagonal, maxillary advancement alone will cause superior movement of the maxilla, and when you add impaction on top of that it can be too much in some cases, especially for the nasal region... "

I'm perplexed by the statement that the maxillary CUT and advancement is 'diagonal' in all cases. Perhaps I'm missing something here but to the best of my knowledge, the Lefort 1 max cut is along the PLANE of the maxilla= ANS-PNS orientation. When ANS is higher than PNS, than that would be a cut along a diagonal plane (due to the inherent orientation) and with no rotation, advancement of the maxilla would cause superior movement because movement is on upward diagonal.

Your ceph tracing (and ceph) show your ANS-PNS (maxilla), orientation is aligned HORIZONTALLY. So, I'm a loss to explain why a 'diagonal cut' applies to you. PERHAPS, something got 'lost in the translation' and he is trying to convey to you that with CCW-r of the maxilla--too much of it via anterior impaction--would change the orientation of your maxilla and put it on on an UPWARD DIAGONAL path and advancement along that type of 'vector' would not look good. IF that is what he is meaning to convey, than that is true. 

Regarding: "....He also said that anterior impaction doesn't autorotate the mandible as much as posterior impaction does. I didn't fully comprehend the explanation on this reasoning though."

I'm also perplexed by this statement IF the statement is meant to be universally true in all cases. To the best of my knowledge, it would depend on the extent of the impaction in one place vs. the other and also which one the particular patient needed the most. The salient info is that BOTH can assist in auto-rotating the mandible to swing up and BOTH can DECREASE the INCLINATION of the MPA (mandibular plane angle) whether or not he tells you he doesn't think it's excessively high.

In your case, you CLEARLY have (evidenced by the ceph tracing, the lower face profile and the mention of such) as SKELETAL OPEN BITE which is AOB (anterior open bite). A key factor with that is that the posterior maxilla is TOO LONG and the excess length there FORCES the lower jaw downward into an unfavorable position where said unfavorable position is making the MPA look too STEEP. The mandible can't swing up to help CLOSE the bite when the posterior teeth are oriented too far down. OK. Hence posterior impaction to the back of the maxilla helps to allow the mandible to swing upward. When it does, the BSSO advancement can displace along a LESS STEEP MPA. The BSSO advancement will take the chin along 'for the ride' and of course, the chin can also be displaced to address to address lip incompetence.

As to the 'steep mandibular plane', perhaps this is a matter of semantics (or subterfuge on the part of how the doctor explained things). VISUALLY, you DO have a steep MPA. Why? Because excess length to the posterior maxilla FORCES it into a steep ORIENTATION. However TECHNICALLY you don't have a steep MPA and it just looks that way BECAUSE the EXCESS to the POSTERIOR maxilla is FORCING it into a downwardly steep orientation. Hence POSTERIOR IMPACTION is going to REDUCE the STEEPNESS that is VISUALLY noticible.

His suggestion resolves to combined impaction and is somewhat consistent with what I said in the first place. The fact that I had to make great efforts to 'translate' what he COULD HAVE meant makes me wonder why he didn't 'talk straight'. However, perhaps he had to battle with or otherwise counter some of your own assessments such as implied preference for posterior downgrafting.

I really appreciate the thorough explanation! A lot of what you say makes sense. My preference was some degree of ccw-r even though this was against your initial assessment, whether that be from anterior impaction or posterior downgrafting (more preferred option). I have a better understanding as to why posterior impaction will help with the MPA now. It's difficult to talk about everything in the short amount of time we have before his next patient, so we're talking quickly and some things get lost. He offered to continue at another time though.

I'm perplexed by the statement that the maxillary CUT and advancement is 'diagonal' in all cases. Perhaps I'm missing something here but to the best of my knowledge, the Lefort 1 max cut is along the PLANE of the maxilla= ANS-PNS orientation. When ANS is higher than PNS, than that would be a cut along a diagonal plane (due to the inherent orientation) and with no rotation, advancement of the maxilla would cause superior movement because movement is on upward diagonal.

For this, he used a skull that had the lefort 1 and bsso cuts made into it to explain. See diagrams below. It is my understanding that he's referring to the cut just at the ANS and applies to all skulls. I was surprised too, and perhaps I'm misunderstanding him. Or he's saying the ANS will always be higher than the PNS due to the anatomy at the ANS. His skull model lefort 1 was particularly angled like in the first photo, but I have seen 'more horizontal' ones too. I'll need to clarify this with him.

https://upload.wikimedia.org/wikipedia/commons/2/26/SchaedelSchraegLeFort123.png

https://media.aofoundation.org/-/jssmedia/surgery/95/95_p360_i320.png?w=620

https://www.mdpi.com/jcm/jcm-11-00562/article_deploy/html/images/jcm-11-00562-g001.png

https://media.healthdirect.org.au/images/inline/original/maxillary-le-fort-illustration-92a268.png

https://paulmittermillermd.com/wp-content/uploads/2021/10/c9830-doublejawsurgeryplanwithosteotomies.png?w=874

[kavan]

I really appreciate the thorough explanation! A lot of what you say makes sense. My preference was some degree of ccw-r even though this was against your initial assessment, whether that be from anterior impaction or posterior downgrafting (more preferred option). I have a better understanding as to why posterior impaction will help with the MPA now. It's difficult to talk about everything in the short amount of time we have before his next patient, so we're talking quickly and some things get lost. He offered to continue at another time though.

Something is getting lost in the translation here. CCW-r via some anterior impaction was not 'against' my initial assessment.However, I was pointing out that posterior excess associated with anterior open bite (which your ceph read out mentions) is not treated via the (OTHER) type of CCW-r which is the posterior downgraft.

Excess length to the frontal aspect of the maxilla can force lower jaw backwards and downwards. Excess length to the back part of the maxilla can do some of that too as in anterior open bite......Your smile ....shows you have maxillary excess to both anterior aspect of maxilla and posterior. So, impaction would most likely be to over all maxilla to shorten excess length which would be a combo of anterior and posterior impaction. A combo of both anterior and posterior impaction yields a NET rotation. If more removed from anterior than posterior then net would be CCW-r. Conversely, if more is removed from posterior than anterior then net would be CW-r. Anyway, with an overall impaction, that is NOT a 'downgraft'.

For this, he used a skull that had the lefort 1 and bsso cuts made into it to explain. See diagrams below. It is my understanding that he's referring to the cut just at the ANS and applies to all skulls. I was surprised too, and perhaps I'm misunderstanding him. Or he's saying the ANS will always be higher than the PNS due to the anatomy at the ANS. His skull model lefort 1 was particularly angled like in the first photo, but I have seen 'more horizontal' ones too. I'll need to clarify this with him.

https://upload.wikimedia.org/wikipedia/commons/2/26/SchaedelSchraegLeFort123.png

https://media.aofoundation.org/-/jssmedia/surgery/95/95_p360_i320.png?w=620

https://www.mdpi.com/jcm/jcm-11-00562/article_deploy/html/images/jcm-11-00562-g001.png

https://media.healthdirect.org.au/images/inline/original/maxillary-le-fort-illustration-92a268.png

https://paulmittermillermd.com/wp-content/uploads/2021/10/c9830-doublejawsurgeryplanwithosteotomies.png?w=874

Now as to the illustrations your surgeon showed you, well they do show the shape of the cuts from the outside of skull and it is true that just about every Lefort 1 cut is above the anterior nasal spine which will be displaced during the surgery. But my reference was to the orientation of the ANS-PNS as one looks at that on a ceph X-ray. This is also termed the maxillary plane. Maxillary planes have different orientations to them. Some diagonally upward, or downward or pretty much horizontal. So, in a 'forward' displacement of the maxilla (ANS-PNS), 'forward' could mean along a horizontal displacement vector or a diagonal displacement vector, either outwards and upwards or outwards and downwards depending on the orientation of ANS-PNS.

Anyway, since we are both perplexed about what your doctor meant by this 'diagonal' displacement, I would suggest you just ask him something like the following:

'My ceph has my maxilla area horizontal with very little inclination. Would this be displaced 'diagonally' forward IF NO rotation at all was introduced by ANY type of impaction to it or would it be displaced along a horizontal vector?'

[TWGOAT]

Occlusal plane is around 12 degrees, i just dont see how surgeon will achieve enough rotation with a 1mm differential.

[kavan]

Occlusal plane is around 12 degrees, i just dont see how surgeon will achieve enough rotation with a 1mm differential.

Thing is that with decompensation (to prepare for surgery) he will have 2 occlusal plans because people with AOB have 2 occlusal planes because their (front) teeth don't actually meet to close the bite for one occlusal plane.

[TWGOAT]

Thing is that with decompensation (to prepare for surgery) he will have 2 occlusal plans because people with AOB have 2 occlusal planes because their (front) teeth don't actually meet to close the bite for one occlusal plane.

Yes but im talking about maxillary plane, its too steep and needs rotation, like 7 degrees which is at least 4-5mm rotation

[kavan]

Yes but im talking about maxillary plane, its too steep and needs rotation, like 7 degrees which is at least 4-5mm rotation

You SAID the 'OCCLUSAL' plane in your prior statement. The maxillary plane is ANS-PNS. Any more confusion you would like to add here?

[Class2]

Thing is that with decompensation (to prepare for surgery) he will have 2 occlusal plans because people with AOB have 2 occlusal planes because their (front) teeth don't actually meet to close the bite for one occlusal plane.

Thanks for all the info in your previous post. I will definitely ask the proposed question to both surgeons.

I'd like to pick your brain for a second. Hopefully I'm just missing something fundamental that you'll make known.

I understand 2 occlusal planes for AOB as seen here: https://pocketdentistry.com/wp-content/uploads/285/c00009_f009-005ad-97814557508561.jpg

In larger AOB cases such as this one: https://thejawsurgeons.com/wp-content/uploads/2021/01/Picture3.png
Posterior impaction makes sense. But what I'm seeing here is a clear inclination of the maxillary plane, where the ANS is higher than the PNS, which makes sense because of the posterior vertical excess.

According to one orthodontist, my AOB is ~0.5mm. I took this photo today which is similar to the ceph/tracing you're referencing from a few months ago: https://i.imgur.com/BtSljSg.jpeg
As you can see, an AOB is not even visually noticeable. I don't think I've ever had a noticeable open bite precompensation, so I don't know how much a decompensation would help now. In the the age 11 photos from my original post, I only see an overbite.

I believe small AOB's like mine can be corrected via molar intrusion. Some mandibular autorotation will occur, and from there, a better idea of what sort of ccw-r would be required.

I don't want my potential ccw-r to be limited by vertical excess, if the rotation can help my airway, aesthetics, and avoiding extracting premolars.

If the lefort 1 cut is truly made to follow the maxillary plane, and mine is of little inclination (or even steep), then I don't see why a larger anterior differential impaction wouldn't achieve the aforementioned benefits of ccw-r.

A posterior impaction would visually improve my MPA by allowing the mandible to swing upward as you had explained earlier, but wouldn't that be limited to the point where AOB is corrected, at which point where there is one OP? Once the AOB is good, the rest is a level impaction to address the excessive gum show. The movement that treats the AOB is the only part of the treatment that would benefit the MPA, but the rest doesn't. Rather, doing the minimum required to address the AOB, and the rest capitalizes on ccw-r in some fashion, rather than just a level impaction to address gum show. ~1mm (or whatever amount to address AOB surgically) posterior impaction with a 4mm anterior impaction for example. On second thought, I stand corrected and if I'm interpreting this study correctly: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8687026/  the remaining 'even' impaction continues to autorotate the mandible in the absence of a differential (due to continued superior movement of the maxilla), and therefore no further ccw-r might be required. But this doesn't 'improve' the maxillary plane, if that plane is to benefit from rotation. However given that both you and my surgeon indicate downgrafting is not needed, the maxillary plane is supposedly satisfactory. I should add, as far as I know my surgeon only had time to glance at the latest ceph without tracing or any numbers, so his preliminary movements were based on in-person visuals and eye balling the ceph.

So assuming I totally didn't miss the mark with the above, it seems to come down to:

A) Mostly combined impaction to treat AOB surgically, reduce gum show, flatten MPA via autorotation and maybe a small 1mm differential ccw-r if the maxillary plane angle is within normal. BSSO and the rest to follow. Drawback is limited bsso advancement if I don't want teeth extracted and therefore smaller b point than with a larger rotation.

or

B) Mostly anterior impaction with a small posterior impaction to treat AOB surgically, reduce gum show (less so in the posterior compared to the above), flatten MPA via autorotation and larger ccw-r if the maxillary plane stands to benefit from being flattened. BSSO and the rest to follow. Potential issues here are if the autorotation and ccw-r combined flattens my face too much, and unfavourable nasal changes.

I found this photo from 13 years one where I was caught laughing at an angle: https://i.imgur.com/aEO3UOj.jpg

It may help illustrate that the vertical excess is more dominant in the anterior rather than the posterior, and where I (incorrectly) may be deducing that rotating the maxillary plane with a larger anterior differential might be the preferred option.

Perhaps you already agree with all of this, and semantics are in the numbers. But you disagree with a posterior downgraft entirely due to the presence of excessive posterior gum show/current maxillary plane angle, and the discussion should only be focused on the degree of level compared to differential impaction.

If you could agree that (1) the gum show is visually mostly anterior, (2) my maxillary plane in the ceph could benefit from more rotation than the 1mm of anterior differential impaction the surgeon suggests could provide, (3) I did not care about my posterior gum show aesthetically, (4) I want to avoid potential negative nasal changes from larger anterior impaction + max adv, (5) the AOB was corrected via posterior molar intrusion (for the sake of simplicity), could you argue in favour of a small posterior downgraft and a small anterior differential impaction?

I'm sorry for my rambling, and thank you for your time!

[kavan]

Thanks for all the info in your previous post. I will definitely ask the proposed question to both surgeons.

I'd like to pick your brain for a second. Hopefully I'm just missing something fundamental that you'll make known.

I understand 2 occlusal planes for AOB as seen here: https://pocketdentistry.com/wp-content/uploads/285/c00009_f009-005ad-97814557508561.jpg

In larger AOB cases such as this one: https://thejawsurgeons.com/wp-content/uploads/2021/01/Picture3.png
Posterior impaction makes sense. But what I'm seeing here is a clear inclination of the maxillary plane, where the ANS is higher than the PNS, which makes sense because of the posterior vertical excess.

According to one orthodontist, my AOB is ~0.5mm. I took this photo today which is similar to the ceph/tracing you're referencing from a few months ago: https://i.imgur.com/BtSljSg.jpeg
As you can see, an AOB is not even visually noticeable. I don't think I've ever had a noticeable open bite precompensation, so I don't know how much a decompensation would help now. In the the age 11 photos from my original post, I only see an overbite.

I believe small AOB's like mine can be corrected via molar intrusion. Some mandibular autorotation will occur, and from there, a better idea of what sort of ccw-r would be required.

I don't want my potential ccw-r to be limited by vertical excess, if the rotation can help my airway, aesthetics, and avoiding extracting premolars.

If the lefort 1 cut is truly made to follow the maxillary plane, and mine is of little inclination (or even steep), then I don't see why a larger anterior differential impaction wouldn't achieve the aforementioned benefits of ccw-r.

A posterior impaction would visually improve my MPA by allowing the mandible to swing upward as you had explained earlier, but wouldn't that be limited to the point where AOB is corrected, at which point where there is one OP? Once the AOB is good, the rest is a level impaction to address the excessive gum show. The movement that treats the AOB is the only part of the treatment that would benefit the MPA, but the rest doesn't. Rather, doing the minimum required to address the AOB, and the rest capitalizes on ccw-r in some fashion, rather than just a level impaction to address gum show. ~1mm (or whatever amount to address AOB surgically) posterior impaction with a 4mm anterior impaction for example. On second thought, I stand corrected and if I'm interpreting this study correctly: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8687026/  the remaining 'even' impaction continues to autorotate the mandible in the absence of a differential (due to continued superior movement of the maxilla), and therefore no further ccw-r might be required. But this doesn't 'improve' the maxillary plane, if that plane is to benefit from rotation. However given that both you and my surgeon indicate downgrafting is not needed, the maxillary plane is supposedly satisfactory.

So assuming I totally didn't miss the mark with the above, it seems to come down to:

A) Mostly combined impaction to treat AOB surgically, reduce gum show, flatten MPA via autorotation and maybe a small 1mm differential ccw-r if the maxillary plane angle is within normal. BSSO and the rest to follow. Drawback is limited bsso advancement if I don't want teeth extracted and therefore smaller b point than with a larger rotation.

or

B) Mostly anterior impaction with a small posterior impaction to treat AOB surgically, reduce gum show (less so in the posterior compared to the above), flatten MPA via autorotation and larger ccw-r if the maxillary plane stands to benefit from being flattened. BSSO and the rest to follow. Potential issues here are if the autorotation and ccw-r combined flattens my face too much, and unfavourable nasal changes.

I found this photo from 13 years one where I was caught laughing at an angle: https://i.imgur.com/aEO3UOj.jpg

It may help illustrate that the vertical excess is more dominant in the anterior rather than the posterior, and where I (incorrectly) may be deducing that rotating the maxillary plane with a larger anterior differential might be the preferred option.

Perhaps you already agree with all of this, and semantics are in the numbers. But you disagree with a posterior downgraft entirely due to the presence of excessive posterior gum show/current maxillary plane angle, and the discussion should only be focused on the degree of level compared to differential impaction.

If you could agree that (1) the gum show is visually mostly anterior, (2) my maxillary plane in the ceph could benefit from more rotation than the 1mm of anterior differential impaction the surgeon suggests could provide, (3) I did not care about my posterior gum show aesthetically, (4) I want to avoid potential negative nasal changes from larger anterior impaction + max adv, (5) the AOB was corrected via posterior molar intrusion (for the sake of simplicity), could you argue in favour of a small posterior downgraft and a small anterior differential impaction?

I'm sorry for my rambling, and thank you for your time!

OK, your post requires 5 separate links/ studies to look at and I don't opine on specific mm measures  aimed at a type of pin point personal analysis. The short of it is that posterior molar intrusion is also a modality used if posterior excess is a factor in the AOB, usually for minor posterior excess. You have skeletal AOB  which is seen in the profile contours whether or not orthodonture improved on or corrected just the 'bite' aspect of it.

I tried to explain what your doctor COULD mean but it's not clear exactly what he means. Exact meanings in terms of mm measures are found on surgery proposal plans generated by sophisticated software. Generally speaking, it sounds to me that your surgeon wants to do an over all impaction to assist with the jaw swinging upward and both a combo of posterior and anterior will do that. It doesn't sound like he's suggesting a large anterior impaction or a large maxillary advancement. I think you should wait until you get a charted out surgery proposal to get a better idea of  his plan is.

[Class2]

'My ceph has my maxilla area horizontal with very little inclination. Would this be displaced 'diagonally' forward IF NO rotation at all was introduced by ANY type of impaction to it or would it be displaced along a horizontal vector?'

I had an appointment for surgical planning with sophisticated software. It was more of a draft, but I like where we are heading. I was able to get this clarified. He said when making the lefort 1 cut, he has to go around the pterygoid plates, so it can't be truly horizontal, at least for this method.