Author Topic: Comparison of two bimax simulations  (Read 172 times)

VincentGT

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Comparison of two bimax simulations
« on: April 25, 2025, 08:29:28 AM »
So here I am again.

Attached you find the pictures of my face.

A few months ago I cancelled a surgery because my surgeon would only do a BSSO and not bimax, although it was always explaind as a bimax. His reasoning: bimax would mean the mandible needs to be advanced (even) more and this would result in flaring mandible corners, which you don't want. The original simulation you find here.

A few weeks after the cancelled appointment, he agreed to make a simulation of bimax ("just to show how little of a difference there is"). So I'm not even sure he would be willing to perform this plan. This bimax simulation you find here.

And although compared like that the difference doesn't seem that great, it actually is if you draw a straight line, like so.

In the meantime I've seen another surgeon who simulated bimax. He understood my wished for a slightly advanced maxilla. You find his simulation right here.

What do we think of these simulations? Any suggestions or opinions?
I think the last one contains some CCW, which would probably be benefifical. But although I have more than enough teeth show, I don't really have a gummy smile today. So I hope this CCW wouldn't change my teeth show drastically.
I don't think I necessarily need genio as there is quite a bit of chin bone. It's always possible afterwards too.

GJ

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Re: Comparison of two bimax simulations
« Reply #1 on: April 25, 2025, 09:16:56 AM »
Tough call. You appear to have a large enough overjet where I'd only do the lower jaw. Moving the upper jaw is where all the problems happen (nose, chimp look, too long/short, etc)...you're in a grey zone. I'd do lower jaw and maybe a small genio.
Millimeters are miles on the face.

VincentGT

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Re: Comparison of two bimax simulations
« Reply #2 on: April 25, 2025, 10:28:40 AM »
The thing is: my upper jaw IS a few mm recessed; every surgeon confirmed this. It’s hard to pass on it then. Here you see a picture of my facewhere I jut my lower jaw forward. I think the maxilla recession is obvious this way. On the right side you a morph with upper jaw advancement.. way better I think.

GJ

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Re: Comparison of two bimax simulations
« Reply #3 on: April 25, 2025, 04:02:01 PM »
To me that's a lot of risk for that slight improvement (if it even is one). The left looks good, and you won't have a wider nose or other risks that come with moving the upper jaw, which will more than offset any gain in the profile. Also, jutting the jaw forward isn't how the surgery will actually look. Most of the problems of jaw surgery come from moving the upper jaw.

If you think the risk it worth it then do it, though.
Millimeters are miles on the face.

kavan

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Re: Comparison of two bimax simulations
« Reply #4 on: April 25, 2025, 06:27:49 PM »
I think you would be OK with the double jaw surgery. Although the upper jaw looks RELATIVELY more advanced than the lower jaw, the upper jaw might not be 'over advanced' in its own right. A bit more advancement would tend to give more support to the base of the nose and give a straighter nose (dorsal) profile and with less downward tip rotation. Also, to get a good advancement to the lower jaw via CCW, they have to cut into the maxilla to affect a rotation. So, it's not as if cutting into the maxilla to provide a CCW-r and with a small amount of advancement is going to risk a bad base of the nose. I mean, a lower jaw advancement can be effected with just the CCW-r and no maxilla advancement. But again, to get a good lower jaw advancement via CCW-r, one does need a Lefort 1 cut to the maxilla to initiate the rotation even if there is no maxillary advancement. From those photos (front), I don't think the prospect of the gonial angles flaring out is going to be any aesthetic detriment either given that you have wide prominent cheek bones.

Basically, I don't see this as an AESTHETIC 'risk' for you to get the double jaw surgery. Looks more to me in the venue of an aesthetic 'pay-off' if you get a little upper jaw advancement and of course the CCW-r for which the maxilla needs to be cut into whether or not you get any advancement. No aesthetic risk either for getting more outward flare to gonial angles. Might even be possible to get a good advancement of the chin point with the BSSO because it can be taken out further with the CCW-r, in which case, you might not need a chin cut for a genio.

Feel free to cross reference what I told you here with the doctor/s who WANT to provide the double jaw surgery given you don't want the guy who just wants to do ONLY the lower jaw.
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GJ

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Re: Comparison of two bimax simulations
« Reply #5 on: April 26, 2025, 10:18:07 AM »
I think you would be OK with the double jaw surgery. Although the upper jaw looks RELATIVELY more advanced than the lower jaw, the upper jaw might not be 'over advanced' in its own right. A bit more advancement would tend to give more support to the base of the nose and give a straighter nose (dorsal) profile and with less downward tip rotation. Also, to get a good advancement to the lower jaw via CCW, they have to cut into the maxilla to affect a rotation. So, it's not as if cutting into the maxilla to provide a CCW-r and with a small amount of advancement is going to risk a bad base of the nose. I mean, a lower jaw advancement can be effected with just the CCW-r and no maxilla advancement. But again, to get a good lower jaw advancement via CCW-r, one does need a Lefort 1 cut to the maxilla to initiate the rotation even if there is no maxillary advancement. From those photos (front), I don't think the prospect of the gonial angles flaring out is going to be any aesthetic detriment either given that you have wide prominent cheek bones.

Basically, I don't see this as an AESTHETIC 'risk' for you to get the double jaw surgery. Looks more to me in the venue of an aesthetic 'pay-off' if you get a little upper jaw advancement and of course the CCW-r for which the maxilla needs to be cut into whether or not you get any advancement. No aesthetic risk either for getting more outward flare to gonial angles. Might even be possible to get a good advancement of the chin point with the BSSO because it can be taken out further with the CCW-r, in which case, you might not need a chin cut for a genio.

Feel free to cross reference what I told you here with the doctor/s who WANT to provide the double jaw surgery given you don't want the guy who just wants to do ONLY the lower jaw.


If the nose widening wasn't a near 100% guarantee I'd agree with this, but I don't think it's worth it given he will most certainly get that. His nose is already on the large side and flares when he smiles. I think this will be bad, but...we shall see.
Millimeters are miles on the face.

kavan

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Re: Comparison of two bimax simulations
« Reply #6 on: April 26, 2025, 02:17:10 PM »

If the nose widening wasn't a near 100% guarantee I'd agree with this, but I don't think it's worth it given he will most certainly get that. His nose is already on the large side and flares when he smiles. I think this will be bad, but...we shall see.

He would not need that much maxillary advancement at all, not to the extent associated with linear advancement when they advance both jaws equally and the upper jaw gets over advanced in the process of getting a good lower jaw advancement (often done in some sleep apnea surgeries). A modest amount would tend to support the base of his nose better and straighten out somewhat the dorsum. Besides to get CCW-r, the maxilla needs to be cut into to effect a rotation and in turn allow for a greater lower jaw advancement.

I've said that before in my post to him and you've said what you've said before. So, both of us have said our say 2X. So, now he has 2 perspectives repeated twice and he can choose between the 2.
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VincentGT

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Re: Comparison of two bimax simulations
« Reply #7 on: April 26, 2025, 03:31:36 PM »
Thanks for both of your opinions. Your views are definitely interesting and a genuine help.

@kavan: can I conclude that you prefer the second simulation (with the CCW-r and without the genio)?

The only things I really worry about with this plan (= the second simulation)?are these:
  • Won’t the CCW change my teeth show too much? According to most surgeons, my teeth show is perfect now (although I would never want any more teeth show — personally, I think I’m flirting with a gummy smile at times).
  • Will the upper lip look thinner and the philtrum longer? Or can this mostly be mitigated through a V-Y suture? Would you assume this V-Y suture is necessary?
  • The nose concerns of GJ are legit, but according to the plan, the maxilla will only be advanced 3 mm. They could also use an alar cinch? I need the septum fixed too, so this will be done at the same time. Also, my nose is quite large in profile, but not that wide — look at the current alar base.

kavan

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Re: Comparison of two bimax simulations
« Reply #8 on: April 26, 2025, 06:51:21 PM »
Thanks for both of your opinions. Your views are definitely interesting and a genuine help.

@kavan: can I conclude that you prefer the second simulation (with the CCW-r and without the genio)?

The only things I really worry about with this plan (= the second simulation)?are these:
  • Won’t the CCW change my teeth show too much? According to most surgeons, my teeth show is perfect now (although I would never want any more teeth show — personally, I think I’m flirting with a gummy smile at times).
  • Will the upper lip look thinner and the philtrum longer? Or can this mostly be mitigated through a V-Y suture? Would you assume this V-Y suture is necessary?
  • The nose concerns of GJ are legit, but according to the plan, the maxilla will only be advanced 3 mm. They could also use an alar cinch? I need the septum fixed too, so this will be done at the same time. Also, my nose is quite large in profile, but not that wide — look at the current alar base.

Sorry, I can't keep track of which plan is which when plans are not all together on the same page and described.

I'm just saying that I think your nose would also benefit by some modest maxillary advancement. You have a slightly convex (slightly) and slightly downward rotation of the tip and the dorsum of the nose stands to get somewhat straightened out and the tip somewhat de-rotated with maxillary advancement. That is to say, in PROFILE perspective, your nose contour is consistent with what you say you have and what other doctors said you had which was somewhat of a recessive maxilla. Also, since you now say that your nose is NOT wide at the alar base, all that is CONSISTANT  with my saying I think your nose would veer in direction of benefit vs detriment--and YES, an alar cinch can be used to mitigate excess unwanted width. If you had a conCAVE nose (a dip in the dorsum) and a turned up tip, that's the type of nose that can experience un aesthetic sequella with maxillary advancement. OK.

CCW-r is associated with getting a larger lower jaw advancement than you would otherwise get without CCW-r assuming the CCW-r in question is a posterior downgraft. If the rotation point is at the ANS, that type of rotation doesn't affect the upper tooth show. The type of CCW-r that can affect the upper tooth show in the sense that it REDUCES a gummy smile is anterior impaction; a slice removed from the anterior maxilla. However, what can increase the tooth show (or gum show) is the maxillary advancement. So, if you want more of a lower jaw advancement than you would get WITHOUT CCW-r posterior downgraft than you would have to weight that in with the possible trade-off of more gum show with the maxillary advancement. So, I would say, the maxillary advancement would benefit your nose profile contour and the cut to do it would allow for CCW rotation to get a good lower jaw advancement. So, you would have to decide if the 2 possible 'pay offs' are worth the 1 possible 'trade-off'.

The upper lip can go 'both ways'. For example if someone gets a LARGE maxillary advancement, the philtral upper lip area can kind of get 'squeezed on' and could look thinner or it could get pushed out too much along an unfavorable native orientation of the ANS-PNS plane (maxillary plane) and start looking conVEX. The other way is that since the upper lip is being brought more forward in the FORGROUND of the picture plane (or the mirror), the upper lip can look more prominent. But to the best of my knowledge, we are talking about a MODEST maxillary advancement that doesn't come with the same boat load of worries that some LARGE ones can come with. So, you would need to ask your surgeon as to any 'need' for V-Y sutures.

Here, I am just going with the flow of your DESIRE to have the maxillary advancement as part of the double jaw surgery and I can buttress some of the reasons behind your desire to have the maxillary advancement. But now you have all these concerns/worries about having that?

Again, I can tell you how things work and you can apply the concepts to weigh the pay offs vs. the trade-offs. I think there are more pay-offs than trade-offs (gains vs. losses) with the maxilla included in the surgery. Best I can do is what I have done via explaining why I think that is so. But I'm not going to 'sell you on' getting the maxillary aspect of the surgery, the very surgery you WANTED to have, gave reason to have which were reasonable to want soon after I validate some of the reasons to have it and then you express a lot of concerns about the very thing you wanted to have.

If you are looking for CERTAINTY, then certainly there is no chance of ANY unfavorable nose changes, no chance of ANY unfavorable changes to tooth/gum show, philtral changes etc. with NO surgery to the maxilla. But then again there's no chance of any favorable changes either with no surgery to the maxilla.


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VincentGT

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Re: Comparison of two bimax simulations
« Reply #9 on: Today at 04:08:01 AM »
Sorry, I can't keep track of which plan is which when plans are not all together on the same page and described.

I'm just saying that I think your nose would also benefit by some modest maxillary advancement. You have a slightly convex (slightly) and slightly downward rotation of the tip and the dorsum of the nose stands to get somewhat straightened out and the tip somewhat de-rotated with maxillary advancement. That is to say, in PROFILE perspective, your nose contour is consistent with what you say you have and what other doctors said you had which was somewhat of a recessive maxilla. Also, since you now say that your nose is NOT wide at the alar base, all that is CONSISTANT  with my saying I think your nose would veer in direction of benefit vs detriment--and YES, an alar cinch can be used to mitigate excess unwanted width. If you had a conCAVE nose (a dip in the dorsum) and a turned up tip, that's the type of nose that can experience un aesthetic sequella with maxillary advancement. OK.

CCW-r is associated with getting a larger lower jaw advancement than you would otherwise get without CCW-r assuming the CCW-r in question is a posterior downgraft. If the rotation point is at the ANS, that type of rotation doesn't affect the upper tooth show. The type of CCW-r that can affect the upper tooth show in the sense that it REDUCES a gummy smile is anterior impaction; a slice removed from the anterior maxilla. However, what can increase the tooth show (or gum show) is the maxillary advancement. So, if you want more of a lower jaw advancement than you would get WITHOUT CCW-r posterior downgraft than you would have to weight that in with the possible trade-off of more gum show with the maxillary advancement. So, I would say, the maxillary advancement would benefit your nose profile contour and the cut to do it would allow for CCW rotation to get a good lower jaw advancement. So, you would have to decide if the 2 possible 'pay offs' are worth the 1 possible 'trade-off'.

The upper lip can go 'both ways'. For example if someone gets a LARGE maxillary advancement, the philtral upper lip area can kind of get 'squeezed on' and could look thinner or it could get pushed out too much along an unfavorable native orientation of the ANS-PNS plane (maxillary plane) and start looking conVEX. The other way is that since the upper lip is being brought more forward in the FORGROUND of the picture plane (or the mirror), the upper lip can look more prominent. But to the best of my knowledge, we are talking about a MODEST maxillary advancement that doesn't come with the same boat load of worries that some LARGE ones can come with. So, you would need to ask your surgeon as to any 'need' for V-Y sutures.

Here, I am just going with the flow of your DESIRE to have the maxillary advancement as part of the double jaw surgery and I can buttress some of the reasons behind your desire to have the maxillary advancement. But now you have all these concerns/worries about having that?

Again, I can tell you how things work and you can apply the concepts to weigh the pay offs vs. the trade-offs. I think there are more pay-offs than trade-offs (gains vs. losses) with the maxilla included in the surgery. Best I can do is what I have done via explaining why I think that is so. But I'm not going to 'sell you on' getting the maxillary aspect of the surgery, the very surgery you WANTED to have, gave reason to have which were reasonable to want soon after I validate some of the reasons to have it and then you express a lot of concerns about the very thing you wanted to have.

If you are looking for CERTAINTY, then certainly there is no chance of ANY unfavorable nose changes, no chance of ANY unfavorable changes to tooth/gum show, philtral changes etc. with NO surgery to the maxilla. But then again there's no chance of any favorable changes either with no surgery to the maxilla.

Thanks, Kavan.

I see what you are saying. The part marked in bold makes sense, but I'm not too sure that I draw the right conclusions from the given simulation.

In this simulation: I can tell that both jaws are advanced and given the slight rise of the mandible there should be some rotation, right? It's hard to tell though whether this is through an interior impaction or a posterior downgraft? The rotation seems modest, but this is likely desirable given that the degree of the gonial angles is already good and the fact that we are talking about only a slight maxilla movement (apparently 3mm). Teeth show doesn't need to change (much) so a modest move makes sense. I did get a few measurements of this simulation by the way: click here.

I think and hope that you are right that the impact of perceived philtrum length will be negligible because of the modest maxilla movement.

Do you think it's problematic that the upper and lower lip don't really line up in the profile view of the simulation? I know lips are notoriously difficult to simulate though.

GJ

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Re: Comparison of two bimax simulations
« Reply #10 on: Today at 05:18:38 AM »
I've said that before in my post to him and you've said what you've said before. So, both of us have said our say 2X. So, now he has 2 perspectives repeated twice and he can choose between the 2.

Yeah. I'm going for a third. Haha.

My concern would be widening more than anything else with the nose. His nose already appears wide, especially when smiling. It will add about 1-2mm of width no matter what cut is made, which will look strange on him.

Considering 99% of our interactions are from the front, I don't think any profile gains would offset that. When he looks in the mirror he will see his nose. When others see him, they will see his nose. Nobody will think "nice jaw in profile"...

They could also use an alar cinch?

Yeah, if they don't you are really screwed. My 1-2mm widening assumed an alar cinch.

---

But, this is your life, your face, and your decision.

I had double jaw surgery. If I had the option for lower only I would have taken that all day long, and if I was slightly recessed after, so be it. It's still a great improvement without messing with the midface. There are also other higher risks of other complications when cutting the maxilla. E.g. Loss of blood/death of the bone (especially if segmented), open bite, a cant, non-union, etc.

Maybe get more opinions. Relle is a good one to see if you can. He's a mix of conservative and more aggressive (when needed), in my experience with him. Take it slow until there's clarity. You don't want to do this twice or regret doing too much/not enough.
« Last Edit: Today at 06:48:29 AM by GJ »
Millimeters are miles on the face.

kavan

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Re: Comparison of two bimax simulations
« Reply #11 on: Today at 12:58:35 PM »
Thanks, Kavan.

I see what you are saying. The part marked in bold makes sense, but I'm not too sure that I draw the right conclusions from the given simulation.

In this simulation: I can tell that both jaws are advanced and given the slight rise of the mandible there should be some rotation, right? It's hard to tell though whether this is through an interior impaction or a posterior downgraft? The rotation seems modest, but this is likely desirable given that the degree of the gonial angles is already good and the fact that we are talking about only a slight maxilla movement (apparently 3mm). Teeth show doesn't need to change (much) so a modest move makes sense. I did get a few measurements of this simulation by the way: click here.

I think and hope that you are right that the impact of perceived philtrum length will be negligible because of the modest maxilla movement.

Do you think it's problematic that the upper and lower lip don't really line up in the profile view of the simulation? I know lips are notoriously difficult to simulate though.

Your presentation is logistically problematically confusing to me for the following reason:
Instead of putting the image files you wanted to be looked at ALL on ONE imgur link and annotating each one (in text) with your observations/perceptions about it, you elected a type of presentation, that is hard (confusing to me) to keep track of.

ORGANIZATION: 3 different tabs must be opened and kept track of to know which one called what in your TEXT link corresponds to what. One called 'this simulation', the next called 'click here' and the other called, 'profile view on the simulation'. When going back to the text in your post and also having the 3 tabs I clicked on, each one says 'imgur, magic of internet'. So, this type of presentation gets confusing to me because it requires me to keep track of which different tab needed to be opened cross references with your question. For example: 'this simulation'= a/G56XSJt.  'click here'=Tu82k9R and 'profile view on the simulation'= a/G56XSJt which is the same as 'this simulation'.

After going through all that, I find that 'click here'=Tu82k9R is (or looks like) the (soft tissue) after proposal of 'this simulation'= a/G56XSJt. Yet 'click here'=Tu82k9R includes a type of displacement read-out that I'm not familiar with. The ones I am familiar with as they apply to CCW-r (posterior down graft) have displacement measures for PNS (posterior nasal spine dropped down). So, I don't see that on the displacement proposal of 'click here'=Tu82k9R.

What I see on the displacement proposal of 'click here'=Tu82k9R is/are listings of 0 rotation for the mandible whereas a CCW-r of the maxilla (via posterior downgrafting) effects an auto rotation of the mandible and also a translation (line distance, 'advancement') BUT under the listing for 'translation' for the mandible, it doesn't list any measures for the proposed advancement. Since he has a field listing for 'auto-rotation' for the mandible where it says 'no movement', from that I would conclude there is no CCW type posterior downgraft rotation in the proposal.

That said, your presentation which was hard to keep track of via the way you organized it in addition to the doctor's ceph read out, that lacks in much clarity is not something I can use to predict a specific outcome. For example, what I said about the different possibilities of unfavorable philtral/upper lip changes being MORE applicable to LARGER advancements to modest ones is generally true. But I can't predict with precision that my mentioning those types RELATIONSHIPS are a predictive guarantee of a person liking what they see in the mirror.

All I can conclude from this presentation is that the  visual found on 'click here'=Tu82k9R which is the SAME (after) visual found on 'this simulation'= a/G56XSJt and also 'profile view on the simulation'= a/G56XSJt shows an improvement to the jaw to jaw relationship given that both the upper and lower jaw recession are addressed. Although it doesn't show nose changes, nose changes do come about via the double jaw surgery. Even with only lower jaw changes, the perception of a nose change can come about given that the nose can look different on the face when another part of the face has been changed.

IF you just FOCUS on the SALIENT visual information the surgeon gave you, the before vs. the proposed after, there is an improvement to be seen (well I see a profile improvement). It's not 'problematic' to me that the upper lip doesn't line up (exactly) with the lower. But consider the doctor wants you to look at the proposed (profile) changes yourself and decide whether or not they are 'problematic' to YOU given that you requested to have maxillary advancement included with your surgery.

In closing, I see DOUBLE JAW recession and good possibility of some profile improvement to the dorsum (bridge) and tip to the nose with the maxillary advancement and also the possibility of getting the alar cinch to mitigate extent of nostril widening. As to the 'BIGness' of your nose that GJ pointed out, the lower jaw advancement helps mitigate some bigness by RELATIVE COMPARISON. For example, when plastic surgeons chart out a rhino, if a person, say, has recession at the chin, a chin advancement is offered to 'balance'. So, in the event, you did get some nostril widening in frontal perspective but also some improvement to the bridge (dorsum) and the tip in profile perspective, there is a type of rhino where they do a wedge resection to the alar rims to reduce excess width. So, what I'm saying is that there is a contingency plan in the event of the possibility that GJ is concerned about. However, if you are concerned about the possibility of nose base width increase as much as he is, then of course the option is there to just go with the single (lower jaw) surgery. What I can tell you is that there is a type of rhino operation (alar resection) in that event.


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kavan

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Re: Comparison of two bimax simulations
« Reply #12 on: Today at 01:28:05 PM »
Yeah. I'm going for a third. Haha.

My concern would be widening more than anything else with the nose. His nose already appears wide, especially when smiling. It will add about 1-2mm of width no matter what cut is made, which will look strange on him.

Considering 99% of our interactions are from the front, I don't think any profile gains would offset that. When he looks in the mirror he will see his nose. When others see him, they will see his nose. Nobody will think "nice jaw in profile"...

They could also use an alar cinch?

Yeah, if they don't you are really screwed. My 1-2mm widening assumed an alar cinch.

---

But, this is your life, your face, and your decision.

I had double jaw surgery. If I had the option for lower only I would have taken that all day long, and if I was slightly recessed after, so be it. It's still a great improvement without messing with the midface. There are also other higher risks of other complications when cutting the maxilla. E.g. Loss of blood/death of the bone (especially if segmented), open bite, a cant, non-union, etc.

Maybe get more opinions. Relle is a good one to see if you can. He's a mix of conservative and more aggressive (when needed), in my experience with him. Take it slow until there's clarity. You don't want to do this twice or regret doing too much/not enough.

Well, if the main concern is the nostril widening, then he would have to be braced for the contingency plan for that which is a rhinoplasty technique called 'alar wedge resection'. They cut out a wedge from where the alar rim meets the face, sew it back medially to reduce excess width. It all depends on how strong his desire is for maxillary advancement is given he cancelled the prior surgery because it didn't include maxillary advancement. However, I don't deny that surgical risks are increased when both jaws are operated on (or even one), I think the doctor should provide the info about those types of risks on a case by case basis.

Please. No PMs for private advice. Board issues only.