Complicated Case / Meeting with Dr Zarrinbal / Any advice appreciated

[krizzobizzle]

Hi All.

I am scheduled to have an appointment with Dr Zarrinbal in a couple of months.

My case is a little bit weird, (I'll explain below)The reason I ask is that he has only responded once via email (I know he is very busy) and I just had a couple of additional questions I would have loved to ask prior to meeting him just so I felt more comfortable.

I'm a classic class 2 overbite case, that was referred for surgery when I was younger but then they decided against it.

The only issue now is that I have mandible implants either side that impinge upon the area where the BSSO cut is likely to be made ( I can explain that in a further post later ) Because of This Dr Z suggested the following in an email.

"I think BSSO is not possible with the jaw implants in place,

maybe alternatively distraction in the anterior part of your lower jaw 33-43,

with opening gaps on both sides to advance the teeth into class I occlusion,

maybe Le Fort I as a second surgery,

the gaps would be closed with the insertion of dental implants.

I found this an interesting suggestion since no one had suggested before, but one which sounds right in my case. I think maybe because I don't have much of a long face or sloped jaw and my chin is in a good position despite having a deep bite and overjet?

The only problem is that I'm unsure what a distraction looks like compared to the transitional BSSO cut and how it's done. I replied to Dr Z but I don't think he checked back, which is fair enough.

So I guess my final questions were

1 ) Would I need braces prior or after, or both?
2 ) How would distraction affect the chin? Does the chin bone move with this all in one piece? Is it similar to a subapical osteotomy?
3 ) Is distraction a common procedure I can't find any similar cases as to what's being suggested.

Heres some pics of my scans - https://imgur.com/a/jFr99Up

Happy to DM anyone private images if they are interested. Any help appreciated as I'm really confused.

Thanks

[IconVillage]

Would you be willing to remove the implants to get a standard bimax? Would be curious to see your images.

[Gadwins]

The chin would be untouched, so I mean it wouldn't be move by this procedure: https://www.semanticscholar.org/paper/Distraction-sagittale-du-bloc-incisivo-canin-Esnault/96531d98e0e9ec066fb1d3c5ce6335dafb0fe77a/figure/4

[krizzobizzle]

The chin would be untouched, so I mean it wouldn't be move by this procedure: https://www.semanticscholar.org/paper/Distraction-sagittale-du-bloc-incisivo-canin-Esnault/96531d98e0e9ec066fb1d3c5ce6335dafb0fe77a/figure/4

God that looks incredibly complicated, almost moreso than BSSO. He seems to want to include more teeth than the example I think.

Would you be willing to remove the implants to get a standard bimax? Would be curious to see your images.

Great question. I dont know. I designed these implants myself to correct a previous surgery. I dont know how complicated it would be to remove them and then do Bimax.

[kavan]

I can't answer for him. So, here I'm just plowing through what he conveyed. Where you see a question mark within my parentheses conveys what I DON'T KNOW about his proposal to you.


OK. BSSO is not possible with jaw implants already in there. That's something I know already. Upshot for BSSO would either to have implants removed before a surgery OR find a maxfax who could remove during a surgery in order to have a BSSO.


33-43 refers to teeth #27 and #22 which are the canines (lower) on each side of mandible. So between canines of each side of jaw is what is meant by 'maybe' distraction to 'anterior' part of jaw. This would leave gaps (between the the canines and the first pre-molars?) on each side.
I always have to look up that type of numbering system for the teeth because I use another one. I'm included a diagram that shows the different numbering systems for the teeth.

gaps left would be filled with dental implants (leaving you with extra teeth to lower jaw?)

then later a Lefort 1 (for what? to move backwards if distraction did not go forward enough?)

Traditional BSSO involves a cut behind the 2ncd molars (mandible). So, in front of the cut moves the lower jaw forward including the chin and teeth whereas a cut aimed at moving the teeth and a section of bone below the teeth (the distraction deal) does not move the mandible forward, just a section between the canines and below them. The chin itself is NOT moved. just a section of the bone above the chin that has the lower teeth section canine to canine. So, similar  to subapical osteotomy. But distraction usually involves a gradual process.

[krizzobizzle]

Kavan you are a star. Just digesting...

[krizzobizzle]

I added more pics with a bit higher resolution and different angles. I'll follow up with some actual pics privately once I can take them properly.

https://imgur.com/a/4Me4mrc

So yea it seems I may be able to get away with distraction because my chin is in an ok position?

But what happens to the bone when you move it forward. If you look at the gap it has to make it up, it's huge. Won't there be a big jutting piece of bone above my chin if that's the case when its moved forward??

Regarding the Le-Fort if you look at my side profile there's no way you can move that back as I would rather have more forward growth. I don't really have much if any. Maybe the le-fort would be to widen the upper arch?

Would it be to move it down or upwards? It looks maybe too counterclockwise?

I think it seems to make the most sense with what he is proposing and yes. I'm guessing the implants would be to close up the gaps.

[kavan]

I added more pics with a bit higher resolution and different angles. I'll follow up with some actual pics privately once I can take them properly.

https://imgur.com/a/4Me4mrc

So yea it seems I may be able to get away with distraction because my chin is in an ok position?

But what happens to the bone when you move it forward. If you look at the gap it has to make it up, it's huge. Won't there be a big jutting piece of bone above my chin if that's the case when its moved forward??

Regarding the Le-Fort if you look at my side profile there's no way you can move that back as I would rather have more forward growth. I don't really have much if any. Maybe the le-fort would be to widen the upper arch?

Would it be to move it down or upwards? It looks maybe too counterclockwise?

I think it seems to make the most sense with what he is proposing and yes. I'm guessing the implants would be to close up the gaps.

I can't predict his surgery for you. What I can tell you is that your chin is pretty much in good place and his objective would be to bring the 'B' point out further where it should be somewhat behind the A point, kind of like close to where I put it. The GAP left behind is about a tooth's width. That's in reference to a dental implant. As to a big jutting piece of bone above your chin, very good question. The answer is that would (most likely)  NOT be done. Only enough to bring the B point close to where it should be behind the A point.

As to 'MAYBE' a Lefort 1 afterwards, the maybe would most likely NOT be a rotation. Up or down can't be answered as that depends on tooth show relative to the LIPS and not something that can be addressed with a bone scan only. Non issue if lefort is to widen as in not something I'm addressing. Because the observation to be made here is that moving the B point outwards can't be moved ahead so much such that a big chunk of bone is sticking out near past your chin point which is why I think the Lefort 1 afterwards is one in the anterior-posterior direction so that the front teeth are not so forward. That could resolve to a Lefort 1 backwards OR a subapical osteotomy where the premolars are removed and also a segment of bone such that the front teeth and the alveolar process could be moved backwards in absence of full Lefort 1.

ETA:  If you had '2 teeth's' worth of space to move the B point further forward so the front teeth were still not that far ahead and a backwards movement to the upper teeth area was not needed, than to blend in the chunk of bone that would stick out above your chin, he would have to use some bone substrate or some kind of bone 'stuff' to blend it all in. Can't cut the area because the teeth roots are in there. Again, I don't know what he's going to do. I'm just good with geometrical balance relationships.

[krizzobizzle]

Great points Kavan.

Thanks for helping me make sense of his suggestions.

I see with your mockup how the piece can only be moved so much or it will cause issues when moved further. I'm still left with an overbite of sorts but much more manageable I'm guessing which is what I would be ok with.

Couple of things on my mind after you did that

1 ) Would it be ok to do orthodontics after the surgery, and avoid it before or is that hard to assess?

2 ) Can I ask why the maxilla portion would likely not be rotated clockwise/counter cw?

2 ) Pushing the front teeth back to me in another surgery to meet some arbitrary line seems like a risky maneuver when I don't have that much forward growth to begin with. Is it the case sometimes where you can get perfect occlusion and tick all the boxes, but it looks way worse than the problem before it?

3 ) When moving the B point as you say to meet the A point, can the bone be "angled" slightly or would that cause too much flare in the lower teeth?

[GJ]

That's a pretty creative solution.

Your front teeth look flared ala Freddy Mercury. Do you have a tongue thrust, etc?
I think Z's plan could work. Might have to graft the step off and retract the upper teeth a bit. It's creative; I'll give him that.

[krizzobizzle]

That's a pretty creative solution.

Your front teeth look flared ala Freddy Mercury. Do you have a tongue thrust, etc?
I think Z's plan could work. Might have to graft the step off and retract the upper teeth a bit. It's creative; I'll give him that.

Lol...they actually look pretty normal in that respect, I'm suprised they dont look freddie-like when I look at the scans.

Couldnt braces do the same thing without retracting the maxilla back, seems like a bad idea.

[kavan]

Great points Kavan.

Thanks for helping me make sense of his suggestions.

I see with your mockup how the piece can only be moved so much or it will cause issues when moved further. I'm still left with an overbite of sorts but much more manageable I'm guessing which is what I would be ok with.

Couple of things on my mind after you did that

1 ) Would it be ok to do orthodontics after the surgery, and avoid it before or is that hard to assess?

2 ) Can I ask why the maxilla portion would likely not be rotated clockwise/counter cw?

2 ) Pushing the front teeth back to me in another surgery to meet some arbitrary line seems like a risky maneuver when I don't have that much forward growth to begin with. Is it the case sometimes where you can get perfect occlusion and tick all the boxes, but it looks way worse than the problem before it?

3 ) When moving the B point as you say to meet the A point, can the bone be "angled" slightly or would that cause too much flare in the lower teeth?

Well, what my 'mock-up' demonstrates is the BASIC (geometric) visual of what he is most likely proposing to do. That's the most important concept that you didn't have which now you have underbelt as a basis for your upcoming consult with him. But now your questions are things that you should ask the doctor during your consult.

1: Orthodontics before or after a possible surgery you've yet to consult about in person. That's for the surgeon to address.

2: As to the MAYBE a Lefort 1 afterwards, the most SALIENT 'maybe' I'm looking at is the anterior posterior direction where that 'maybe' would be to address the upper front teeth STILL being too far ahead AFTER the B point area is moved forward. So, the mock up makes it intuitively obvious what direction the 'MAYBE a L1 afterwards' would be.

As to most likely not a rotation. I stand corrected here. I should have said, most likely not for ME to ponder at this point in time because it involves an 'if this then that' type scenario involving many possible 'ifs' to ponder and explain.

2: 'Pushing the front teeth back....forward growth....': I can't opine on your forward growth. Landmark points are absent in your scan. Lines in cephalometric analysis constructed from landmark points are not 'arbitrary'. They are based on normative relationships. The illustration I presented is limited to SHOWING a VISUAL that corresponds to his suggestions. What the example shows is that one tooth's width of distraction gives some visual information as to what the lefort 1 'MAYBE LATER' might be for the front teeth not to be that much still ahead. So, when I show a visual example of what something could mean, it's not something where my objective is to jump in and take over for Dr. Z.

3: The visual doesn't show the B point meeting the A point. It shows that even IF that were done, there would be a chunk of bone sticking out above the chin that would be needed to be blended in. It also shows that even if that were done, the front teeth would still be ahead. Albeit, 'seeing' that from the illustration depends on visualization. The rest of your question about angling the teeth bearing bone demonstrates that you can visualize that doing so (theoretically, geometrically) would tend to make less the overhang of the top front teeth. But doing so would be a function of what the DISTRACTION DEVICE does or can do which is something you would need to ask the doctor using what ever distraction device he's going to use.

[krizzobizzle]

Really appreciated the advice, albeit worded sternly sometimes. 

I'm curious. You have a fantastic knowledge of orthodontics and orthognathic surgeries and seem very well read. Have you ever considered studying it or is it just a hobby you like to help with from afar?

[kavan]

It's just something that comes easy to me in the sense of figuring out what's going on and answering some questions. I've always done well (as in off the charts in less time than they give to finish it) on capacity type tests, IQ type spacial reasoning, logic questions, geometrical relationships...stuff like that most MIT types have going on long before they ever enter. So, it's not really a matter of my having extensive knowledge about the surgeries. It's more of a matter of being able to relate to the relationships they look at.

It's NOT a thing where I would actually be good at DOING a surgery. I know my limitations. I can't put a screw in the wall without making a big hole. Nor can I cut a thanksgiving turkey correctly nor am any good at cutting and sewing. Diplomacy isn't a forte of mine either. So, here is just a volunteer hobby.

[kavan]

All, in all, to the best of my knowledge, distraction is a gradual process. So, you can observe it as it goes along and it would tend to be a 'wait and see' process regarding the 'maybe' of a later lefort 1. So, there's no need to think about the L1 right now. It doesn't seem like he's holding contingent that you have a lefort 1 later down the line if you get the distraction. The distraction alone would tend to make less the over cliff of the front teeth.  When the distraction period is over, he will have to remove the device and at that point you can decide to keep the residual overhang or go to the next surgery proposal to mitigate it more.