Preparation for DJS, advice needed

[kubabuk]

Hi, it's my first post here. I've seen some really detailed and well written answers on this forum, so I thought writing here would be a good idea.
I'm preparing myself for DJS and would be very grateful for some advice. If you could share links to some good reading materials so I could educate myself better, that would be great too.

History:
I'm 24yo male and have micrognathia. At 16-17yo I had braces to camouflage my overbite and fix teeth crowding and had one upper molar extracted on each side.

Goals:
I would like to have DJS to fix my recessed jaws (both mandible and maxilla). The most noticable defect is my small mandible, but the maxilliary recession is also a problem. I would like to  remove the deep chin fold, decrease the nosalabial angle and have more teeth show at rest. If my nose becomes more upturned that would be good too (you can notice it droops clearly on ceph photo)
A minor goal could be to widen the maxilla a little bit. Maybe a 3-piece DJS would be a good idea?
After the surgery I will probably need to shave my chin-bone, but it's something I'll worry about in the future.

Problems:
I have resorbed roots in my upper incisors. It's not too bad (the roots are still long enough), but I wouldn't want to move my upper teeth too much anymore. I think reversing the camoulfage (that is: reopening the gaps and putting implants in place of missing molars) would not be an option for me.
On the other hand my teeth are positioned in such a way now, that there is not much place to move mandible forward with respect to maxilla. So my teeth/jaws are in good position relatively to each other, but I still have a little overbite and both my jaws are recessed.



My only option right now is to have insurance-covered operation (Lefort 1). As far as I know surgeons in my country perform CCW rotation of maxilla.

Based on all the info could you tell me what should I aim for? F.i. should I try to convince my surgeon to do a CCW rotation, or maybe it's not a good idea in my case? How much do you think I should move my jaws forward, if you could give some rough estimate („a lot”, „a little”, etc.)?
Also, what are the posible issues with this sort of operation? Should I be worried about something, f.i. recession of other parts of my face after moving both jaws forward?
And lastly – do my airways look small based on the ceph? I know it's a common issue in people with micrognathia.


I would be really grateful for some help, since the topic is still quite new and foreign to me.



Photos:

https://imgur.com/a/HmnZwQ7

ceph:

https://imgur.com/a/rw01Mtd

[GJ]

First off, thanks for a well-written post. Very easy to follow the issues and concerns.

Do you have an x-ray showing the root resorption? This would help see if you can do ortho safely. You want at least a 1:1 tooth to root ratio.

Just some observations:

- The right side of your face is a little longer. Looks to be creating a cant. It's not major and whether you address it in a surgery or not is probably optional and dependent on the surgeon's skill.

- Your current tooth show is pretty ideal. I'd be concerned about losing that.

- I don't see major recession here. Your lower jaw is behind the upper, but it has that classic "Morgan Dollar" profile, which is clearly ideal since it's on a coin. It's not uber masculine, but it's nice. Yours might be ever so slightly more recessed than that. I'm not sure it's worth all the risk.

- If it's worth the risk, then I think a linear movement with chin reduction as the best option. Your bite plane is flat as-is, and your chin prominent. If you increase POG, then the chin will be too far out. Hence the need for reduction. This gets dicey, IMO. CCW would bring the chin/POG out even further, and it would also make your flat bite plan even flatter if not inverted (not sure the term for this if the angle actually goes the other way).

All considered, I think doing nothing is your best option, and for me it would be an easy decision.

There is a guy on YouTube (Vinny jaw break or something like this) who had a similar profile to yours and looks great after, but he had lower only and they created an exaggerated overbite to make that work. Given you had uppers pulled, it limits that option, which would have been a good one.

[kubabuk]

Thanks for the answer. I thought about it long and hard and I really want to fix my jaws. My decision is pretty much final, but now I'm not sure what exactly can be done in my case.

I still have some questions and small objections, I would be grateful if you could adress them.

The roots are longer than the crown, so they are long enough, but I seem to have tendency to resorption. I think I need to be careful and take it into consideration before another ortho treatment.

My face seems asymetrical, but I think it's my crooked nose rather than anything else.

My tooth show at rest is not really that good. You can only see my bottom teeth if anything at all. I think it's caused by recessed maxilla. Check my profile photo where I'm smiling - you can see how far behind my upper incisors are compared to my upper lip. I'm also concerned about all the soft tissue around the lips not having enough bone support.

Do you think linear movement of BOTH jaws would give me the desired results? Why would chin reduction be dicey? And how could I lose my current tooth show? I would imagine any kind of movement forward with maxilla would increase my tooth show? I don't know, maybe my intuition is wrong here.

Maybe my bite plan seems flat because my head is not in a neutral position? What do you think - could that be the case? I do have a tendency to tilt my head up to hide the recessed jaws a little bit.

I think the photos I posted make me look better than I really look. I will post some more photos, maybe it will give you a better idea of what's the problem.

[kubabuk]

Profile picture, different lighting and head tilted down compared to the previous pictures. I think that's my "neutral head position":
https://imgur.com/a/iKPjSKS

Profile picture showing my maxilliary recession. I hold my upper lip closer to my teeth on this pic:
https://imgur.com/a/c1zYmDY

On these photos you can also see all the soft tissue sagging that I would love to fix.

[GJ]

Profile picture, different lighting and head tilted down compared to the previous pictures. I think that's my "neutral head position":
https://imgur.com/a/iKPjSKS

Profile picture showing my maxilliary recession. I hold my upper lip closer to my teeth on this pic:
https://imgur.com/a/c1zYmDY

On these photos you can also see all the soft tissue sagging that I would love to fix.

These photos show recession better.

I still think a linear movement might be better than CCW in this case. Your chin is so prominent it complicates the issue. If you had all your teeth, the best plan would probably be extract two lower premolars and advance lower only. Given your current situation, I guess you are stuck moving both jaws. I lean toward a linear movement. Chin reduction likely necessary after that.

[kubabuk]

I think I would move the maxilla forward either way - my ortho and dentist both said it's recessed; besides I think you can see it clearly on one of the last photos.

Why would my chin be a problem? You can always shave the bone and it's not a complicated procedure; or is there something I'm missing here?

If hypothetically the ceph is tilted and in reality my bite plane is not that flat (I'm not sure whether that's the case or not) would CCW rotation have some advantages over linear movement?

[GJ]

If hypothetically the ceph is tilted and in reality my bite plane is not that flat (I'm not sure whether that's the case or not) would CCW rotation have some advantages over linear movement?

Yes, it would allow the lower jaw to come out more than a linear movement. Kavan could probably explain this better in terms of the geometry, but I think that extra movement would be "tangential." Basically whatever that curve is from the rotation should be added to the projection. I think this would look strange, and maybe function poorly, given your current setup since your bite plane is almost flat.

Regarding the chin, it's so large relative to the jaw, that I think it's a dicey situation trying to get that to look natural. Sure, anyone can shave it, but getting a large bone like that to look natural after reduction is something that would concern me.

These are my opinions. You'll get more since you provided good records and well-written thoughts.

[kubabuk]

Thanks for your help, I think you gave me some really valuable advice.

[kavan]

Your chin is in a good position (relative to the lower lip) in it's 'own right. But you have bimax recession and chin would look better with lower jaw advance (after a rotation pushes it backwards and down). You're a 'low angle' MPA (mandibular plane angle), your OP (occusal plane) is flat (not steep). So, you are NOT a CCW case. (more like the opposite of CCW)

You are  in the venue of CW (clockwise rotation) around the insisor point. That rotation will bring your nose base area forward and the chin backwards. It will also give you more tooth show and address what they call 'short chin' which you have. This rotation is done via a lefort 1. This would be bimax surgery because they would probably want to bring the lower jaw forward (upper too) which will be brought 'forward' along a STEEPER MPA which will improve your LOW ANGLE MPA. Nothing need be done separately to the chin. Although it is brought backwards with the CW-r, it would come forward with the mandible advancement.

Included is a diagram about rotations.

ETA: Linear advancement is a term used when there are NO rotations and both jaws brought forward, often by same amount, along the same 'line' of inclination you already have. High or LOW angle patients usually benefit from a rotation. CCW for HIGH angle patients and CW for LOW angle patients.

Geometrically speaking however, displacements (movements) of the maxilla and/or mandible always move along the inclination of their 'line' orientation whether or not the orientation of the line they are to move along is the same one they started with, as is the case with 'linear advancement' with no rotations, or advancement when inclination of line is changed via a rotation.

[kubabuk]

Thanks for such a detailed response.
You are talking about mandibular advancement, but how would that work in my case? As I wrote my jaws can't be moved relatively to each other because of the previous orthodontic treatment (camouflage with extractions). Did you mean both mandibular and maxilliary advancement?

[kavan]

Thanks for such a detailed response.
You are talking about mandibular advancement, but how would that work in my case? As I wrote my jaws can't be moved relatively to each other because of the previous orthodontic treatment (camouflage with extractions). Did you mean both mandibular and maxilliary advancement?

Yes.

[kubabuk]

All right, so the idea would be to tilt my jaws CW and then advance both of them along this new, steeper plane. This way the chin itself would stay in place and would not need to be cut/shaved.

Could you tell me what are the advantages of CW over simply moving my jaws linearly? Intuitively, it seems like CW would give me an even more receeded-looking mandible. Besides, maybe moving my jaws linearly and shaving the chin-bone would actually be a good idea from the aesthetic point of view, since my mandibular incisors look so far behind the chin (I would like to make the labiomental groove a little bit smaller than it currently is). On the other hand I agree that my chin looks short from the front, so maybe it would look even shorter after shaving the bone?

It's hard to tell without some kind of visualisation, so maybe I will have to wait for my appointement with the surgeon. By the way - what do you think about reliability of computer-aided planning?

One more quesstion: would jutting my jaw forward give me some vague idea of how I would look like after the operation? I know that the jaw movements would be different (both jaws would go forward and they would not change their position relatively to each other), but maybe the visual effect could be roughly simulated by jutting the mandible forward? What do you think?

[GJ]

IMO CW does result in an angle that would result in more bony recession, which is why I said linear. I'm not sure if Kavan sees something else or has a different opinion on that.

[kavan]

OK, strictly speaking, if I drop a vertical from your lower lip, your chin is prominent because the chin point goes beyond the vertical drop down line from the lower lip. But 'in it's own right', that type of prominence would not be considered 'bad' for a male chin.

GJ is telling you that your chin is prominent and will become MORE prominent with linear advancement (true) and prominent enough that you will most likely need to compensate for the excess chin prominence that would arise with linear advancement via chin REDUCTION; (true) a separate surgery to the chin. So, yes, I would agree that linear advancement would make your chin overly prominent and require a separate surgery to the chin to reduce the extra prominence you'd see with the chin.

So, part of the matter is one of HOW to REDUCE chin PROMINENCE with double jaw surgery. Is it not? 2 ways to reduce the chin prominece:

1: Linear advancement with separate surgery to chin that will have increased prominence with linear advancement and therby will need to be reduced due to that.

2: CW-r which will rotate the chin point (Pog) down and back and thereby reduce the chin prominence and without a separate surgery to the chin to reduce prominence.

The other part of the matter is that when I look at other angles of the face, such as SNA and SNB, the SNA (associated with maxilla orientation) is a little above the norm and SNB (associated with mandible orientation) is also a little above the norm. SNA is more above the norm than is SNB. So now, I'm not that convinced the maxilla is recessive and I'm now questioning if the mandible is recessive. I disclose I didn't CROSS REFERENCE your SNA and SNB angles with your self assessments of recession to BOTH JAWS.

Although your initial entry was 'easy to follow' for GJ, it wasn't for me. For example, you were preparing for DOUBLE JAW surgery but with ONLY option of the Lefort 1 (single upper jaw surgery). Also, you wanted to know if you 'should try to convince' your surgeon to do something. To me, that type of question conveys you want to be a 'back seat driver' telling your surgeon what he/she needs to do. But don't know the directions yourself. Although you're not expected to know HOW to DIRECT your surgeon, another 'back seat' driver from here (even if it's me) can't be expected to proxy to direct him/her for you to convince of those directions.

So, basically, I'm saying I most certainly don't see you as a CCW candidate. As to linear advancement vs. CW, the former will depend on if you really DO have bimax recession to be addressed by advancing BOTH jaws in addition to chin REDUCTION and the latter will depend on if you really DON'T have bimax recession and have ample prominence of the chin point where rotating it CW would balance out/look better by rotating it backwards and down to decrease it's shortness and prominence.

What would be easier for me to follow would be a displacement PLAN from your surgeon.

As to jutting your jaw forward, it doesn't mimic the results of surgery.

[GJ]

So now, I'm not that convinced the maxilla is recessive and I'm now questioning if the mandible is recessive.

I agree with that...at first I didn't think he was recessed.

The second set of photos seem to show he is recessed "in the flesh", but now it's a question of which is accurate. Ceph and first set of photos look like Morgan Dollar profile, which isn't necessarily recessive just a bit more feminine than some like.