Asymmetry due to differing mandibular angles - how to fix?

[ceylon]

Asking about a particular kind of asymmetry that causes one side of the jaw to look larger: What's it called when the left and right halves of the mandible are the same length and thickness, but when viewed from above one angles out more than the other, causing that side to look wider when viewed from the front? Like if the mandible in overhead view is a lopsided V where the sides are the same length but at different angles. The face looks wider on one side not because that side mandible is larger or longer, but because of the more obtuse angle compared to the narrow side.

What osteotomy procedures can correct this?

[kavan]

Asking about a particular kind of asymmetry that causes one side of the jaw to look larger: What's it called when the left and right halves of the mandible are the same length and thickness, but when viewed from above one angles out more than the other, causing that side to look wider when viewed from the front? Like if the mandible in overhead view is a lopsided V where the sides are the same length but at different angles. The face looks wider on one side not because that side mandible is larger or longer, but because of the more obtuse angle compared to the narrow side.

What osteotomy procedures can correct this?

Your description of how something looks from a specific vantage point  (looking directly overhead/from above), doesn't reflect how someone would actually look at someone's face since it's not viewed from that perspective. Even if you were looking at a 3 d scan of the skull from upper view,  the jaw area wouldn't be in view from that vantage point, yet alone it's length, width or angle.
Direct overhead views don't yield information about the object's length.

So, let me take a GUESS at what you could be observing and are trying to ask.

Are you wanting to know what kind of operation can SELECTIVELY rotate an inwardly rotating posterior jaw angle more laterally outward?

[Post bimax]

You're likely talking about some form of unilateral hyperplasia.  Likely at the TMJ/condyle and is now pervasive for that side of your face. My face is sort of like this.  For example, here is the overhead view from Gunson's TMJ analysis:

https://imgur.com/a/zkJA9vr

I don't know exactly how to interpret this (and you can't see the mandible specifically), but viusally the right side of my face is definitely 'wider' than the left.  I'm guessing this is the sort of thing you're talking about.

For the record, I don't think this kind of asymmetry can be 'fixed'. Especially after growth has stopped.  Assuming this is actually what you're talking about.

[ceylon]

To clarify, in transverse cross-sectional view from above, as in a "slice" from a CT. I attached a pic of the for an example of the view, but imagine the jaw is asymmetrical with one side angled further from the bilateral midline than the other.

From the front, creating more fullness on one side similar to the patient in the other asymmetry post. (I don't know what the cause of hers was, but it seems like hyperplasia on one side in addition to chin asymmetry. They were able to correct it - how?)

Are you wanting to know what kind of operation can SELECTIVELY rotate an inwardly rotating posterior jaw angle more laterally outward?

Yes, either that or rotating the overly obtuse side in, or a combination of both. Basically, how to get both angles of the V to be equidistant from midline to restore facial symmetry?

[kavan]

The slice you showed shows a X section of the ARCH where there is a more of a 'bump out' to one LINGUAL side than the other linqual side. The contour of the BUCCAL side which is the side seen when someone is looking at the face looks OK. CT slice isn't a perspective where I look at angles. We look at angular relationships on a ceph or from a frontal photo.

As to the article the photo comes from, the authors say they corrected the asymmetry that caused her to tilt her head to compensate for it and the surgery included a Lefort 1 and BSSO but they didn't elaborate on all the specific displacements done. Besides, since ONLY one person could even answer what side she was tilting her head to (my open QUIZ), I won't be using her photo as an example here. However, that quiz where the photo is found is still open if you want to use the information the authors gave to posit which jaw her asymmetry most likely came from.

[ceylon]

You're likely talking about some form of unilateral hyperplasia.  Likely at the TMJ/condyle and is now pervasive for that side of your face. My face is sort of like this.  For example, here is the overhead view from Gunson's TMJ analysis:

https://imgur.com/a/zkJA9vr

I don't know exactly how to interpret this (and you can't see the mandible specifically), but viusally the right side of my face is definitely 'wider' than the left.  I'm guessing this is the sort of thing you're talking about.

For the record, I don't think this kind of asymmetry can be 'fixed'. Especially after growth has stopped.  Assuming this is actually what you're talking about.

Thanks! This is the kind of picture I meant but I didn't know what terms to search for. I'm still trying to learn the vocabulary, so thanks for your patience. (The pic I posted before is wrong, sorry!)

In my case the TMJs and left and right mandible are equally sized in terms of bone mass on both sides, BUT the left side "arm" is angled out further than the right at the lower back corner of the jaw (angle of mandible) - like it's flipped out and up at the corner, protruding more outward. The maxilla is symmetrical, as is the width of the face where the jaws hinge.

This may be naïve, but is it not possible to reposition that corner so it's sticking out less, so the angle of mandible on left and right are symmetrically positioned? What would that procedure be called?

I appreciate your explanations as I'm really trying to learn. It's a struggle to express what I mean when I don't have the right words. Making a plasticine model might be more effective, haha

Editing to add: Can you point me to any good articles/papers about diagnosing and surgically treating asymmetry or dysymmetry? An initial googling only showed me that there are many types and causes. I realize a starting point for self-education is what I need.

[kavan]

The best way to get help here is to post your photos and cephs and not photos you find somewhere that aren't of you.

[ceylon]

The office is sending them to me, I haven't got them yet.

[GJ]

Rare situation where a custom implant is probably the best way to address this.

[eastcoastian1]

Rare situation where a custom implant is probably the best way to address this.

I had custom done. Did not fix the asymmetry.

[kavan]

Rare situation where a custom implant is probably the best way to address this.

Well, for reasons I touched on prior, it hasn't been established what her situation actually is by the way she's trying to describe it .

[ceylon]

In this case, the asymmetry appears to be fixed through orthognathic surgery making the overly protruding side smaller - so it can't be an implant. In the after, the mandible is laterally narrower as a whole. What procedures achieved this?

It's the situation I was attempting to describe with one side appearing wider due to the angle of mandible at the jaw corner protruding (therefore the ramus on that side bowed out??), whilst the chin is reasonably central and height of ramus on both sides equal in length.

Eager to hear your thoughts.

Edit: added emphasis and rough diagram

[kavan]

In this case, the asymmetry appears to be fixed through orthognathic surgery making the overly protruding side smaller - so it can't be an implant. In the after, the mandible is laterally narrower as a whole. What procedures achieved this?

It's the situation I was attempting to describe with one side appearing wider due to the angle of mandible at the jaw corner protruding (therefore the ramus on that side bowed out??), whilst the chin is reasonably central and height of ramus on both sides equal in length.

Eager to hear your thoughts.

Edit: added emphasis and rough diagram

Inability to answer your own question arises from faulty observation and supposition. You start by positing something that might not be correct. But you don't question your own assumption. Instead you just posit it's his jaw angle (gonial angle) that's the cause of his asymmetry and try to describe it by ways the gonial angle isn't looked at.

For example, the gonial angle ('mandibular' angle) is looked at via profile view and if it's BONE you're referring to, the ceph is used. The gonial angle is not assessed from an overhead view nor a frontal view. So descriptions about how 'obtuse' one side is from views it's not evaluated don't go far.

Now because I see that you DO want to THINK about things, instead of giving the (general) answer to what he most likely had done, I'll help you think it through with some hints which should help you figure out what he most likely had done.

1: Question your assumption/supposition that his asymmetry is DUE to--as in caused by-- his jaw/gonial/mandibular angles being different. Ask yourself if he could still have the type of asymmetry he has IF his jaw/gonial angles were the SAME degree measure. Is his asymmetry 'caused' by his jaw angles OR is his jaw angle area looking the way it does the EFFECT of something else.

2: Re-evaluate your observational skills by drawing reference lines to take a closer look at what you might not be seeing without them. I've made this easy by drawing them in for you on the photos you posted. Consider that good observation as to where the asymmetry is coming from will allow you to take a good guess at what he most likely had done.

I hope this helps you (or anyone else) make a good guess and explain the reasoning.


(This exercise open to ALL who wish to answer in addition to the OP.)