Author Topic: Insufficient correction of retrognathic mandible  (Read 19703 times)

timang

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Insufficient correction of retrognathic mandible
« on: August 08, 2014, 10:46:37 PM »
Post-op these patients still have small lower jaws. A bone structure that prevented significant lower jaw advancement or bad surgical planning?




Tiny

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Re: Insufficient correction of retrognathic mandible
« Reply #1 on: August 09, 2014, 12:18:26 PM »
IMO these results are not too bad.  The lips line up fine and the chins are well within normal range.  Maybe they had BSSOs but no genios? Maybe they didn't want prominent chins?  They also both are carrying excess chin fat.

There is a limit to how much advancement can be done.  The upper limit seems to be around 15mm (10mm BSSO 5mm genio) at least in women, maybe a bit more for men

Also, if someone has had upper extractions to "correct" an overbite but the plane of their bite means they can't have CCW with le fort, then the only way to create sufficient space is lower extractions which not everyone will want

notrain

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Re: Insufficient correction of retrognathic mandible
« Reply #2 on: August 09, 2014, 01:07:57 PM »
Also, if someone has had upper extractions to "correct" an overbite but the plane of their bite means they can't have CCW with le fort, then the only way to create sufficient space is lower extractions which not everyone will want

No, you can re-open the extraction sites and place implants there. This is time consuming of course, but you can pretty much reverse any orthodontic treatment you ever had. The best way to do it is have surgery without any prior orthodontic compensation obviously.

Tiny

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Re: Insufficient correction of retrognathic mandible
« Reply #3 on: August 09, 2014, 01:54:41 PM »
No, you can re-open the extraction sites and place implants there.

Sure you can, but it rarely seems to be done...

notrain

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Re: Insufficient correction of retrognathic mandible
« Reply #4 on: August 09, 2014, 02:18:07 PM »
it is done if there isn't another solution available. this guy in germany had his extraction spaces reopened (he had teen ortho and surgery as an adult): https://www.youtube.com/watch?v=qsEax4GmfS0&list=PLB214A3BC35593937#t=281

Alue

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Re: Insufficient correction of retrognathic mandible
« Reply #5 on: August 09, 2014, 03:22:26 PM »
No, you can re-open the extraction sites and place implants there. This is time consuming of course, but you can pretty much reverse any orthodontic treatment you ever had. The best way to do it is have surgery without any prior orthodontic compensation obviously.

I'm not sure how well your gums would hold up to all that movement.  It seems like a gamble to me. 

timang

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Re: Insufficient correction of retrognathic mandible
« Reply #6 on: August 09, 2014, 08:51:09 PM »
Maybe they had BSSOs but no genios? Maybe they didn't want prominent chins?

The first patient had maxillary impaction to correct gummy smile, BSSO to advance mandible and genioplasty. Her chin is fine as it is. More agressive genio would have made her looks worse imho so that wouldn't have been a good option to address her small lower jaw.


Lazlo

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Re: Insufficient correction of retrognathic mandible
« Reply #7 on: August 09, 2014, 11:18:29 PM »
it's not a satisfying result to me. gunson and arnett to much better jobs on jaws just as recessed.

timang

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Re: Insufficient correction of retrognathic mandible
« Reply #8 on: August 10, 2014, 04:44:43 AM »
it's not a satisfying result to me. gunson and arnett to much better jobs on jaws just as recessed.

Are you able to elaborate how their surgical plans would have been different?

ForeverDet

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Re: Insufficient correction of retrognathic mandible
« Reply #9 on: August 12, 2014, 09:11:23 PM »
There is a limit to how much advancement can be done.  The upper limit seems to be around 15mm (10mm BSSO 5mm genio) at least in women, maybe a bit more for men

Where are you getting those upper limit figures?

There are no limits (except in the sense that even if a person has no almost chin that the advancement wouldn't exceed say 40ish mm to bring it to a class 1 position) as many surgeons, usually using counter-clockwise rotation, have advanced the chin point up to 40mm. My chin came forward 21mm after double jaw surgery and a genio. Now when you get above 20mm, that much advancement is for extreme cases obviously but without almost exception, cases where there is still recession after surgery is due to the surgeon's not utilizing CCW rotation.

Are you able to elaborate how their surgical plans would have been different?

Using CCW rotation most likely. It is necessary because it not only addresses where the abnormal growth occurred but also it allows for large advancements. 

With that said, those two cases above do still show some residual recession and steep mandibular places but they look fine. I wouldn't call it bad surgical planning but it wasn't optimal.

goodula

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Re: Insufficient correction of retrognathic mandible
« Reply #10 on: October 19, 2015, 04:50:15 AM »
Thing is the first pacient there not only had a recessive mandible and chin, but she also had a gummy smile, which limited the planning possibilities. In her case, I think that her face height was fine, so doing a normal counterclockwise movement was not that big of an option. You can't always make a CCW rotation as we all want, because you must also make the pacient functional (this was explained to me by the very same doctor who operated this woman). In my case for example, they rulled out a CCW rotation, because my palate was too low, face was to short and upper teeth too proclined, so instead they did a clockwise rotation which in turn elevated my palate and made my face longer. In the end it ended up fine, and profile looks straight (not recessive anymore) allthough they made a clockwise rotation (they compensated by bringing the lower jaw forward on an artificially created overbite - premolars where extracted in lower jaw - and a genioplasty).

To me it looks this woman has the same problem; if they would have rotated too much CCW of course she would have got a better chin, but her upper jaw would have looked very messed up (upper teeth would have been proclined, and could have ended up protruding through the lips).

So it is true that sometimes you are limited by the skeleton, but actually the results in the pictures are good, within normal values. Take notice that as opposed to men, women look better with a slightly reccesive chin, while in men we expect a straight profile, even a slightly concave one (with protruding chin).

jesterofmalice

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Re: Insufficient correction of retrognathic mandible
« Reply #11 on: October 19, 2015, 06:07:53 AM »
I think the first one in particular is a fairly good result, really.
She looks quit good and I think her chin looks fine.
I see the problem in her 'after' is that she still doesn't have a jaw line. You can't see the mandible at all.
I'm assuming this is due to having narrow jaws (and a narrow chin?), and that simply moving the jaws forward doesn't really affect this much?
If so, I'm not sure what she would need to give her a more defined jawline? She needs more 'width'.

jesterofmalice

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Re: Insufficient correction of retrognathic mandible
« Reply #12 on: October 22, 2015, 02:20:50 PM »
ramus height

But it needs to come out more, no?  Not just longer. It needs width so that it can can create some definition...

kjohnt

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Re: Insufficient correction of retrognathic mandible
« Reply #13 on: November 30, 2015, 07:21:23 PM »
It appears both women have short ramuses (plural form of ramus?) and narrow mandibles, though width would be easier to see from the front.  Projection isn't the only thing that leads to jaw definition.  It's too bad there isn't an easy fix to a narrow mandible, because width at the angles is more important than ramus length in my personal opinion.  With that said, I think both of these cases could have used more chin projection from genioplasty, maybe 3-4 mm. 

Thing is the first pacient there not only had a recessive mandible and chin, but she also had a gummy smile, which limited the planning possibilities. In her case, I think that her face height was fine, so doing a normal counterclockwise movement was not that big of an option. You can't always make a CCW rotation as we all want, because you must also make the pacient functional (this was explained to me by the very same doctor who operated this woman). In my case for example, they rulled out a CCW rotation, because my palate was too low, face was to short and upper teeth too proclined, so instead they did a clockwise rotation which in turn elevated my palate and made my face longer. In the end it ended up fine, and profile looks straight (not recessive anymore) allthough they made a clockwise rotation (they compensated by bringing the lower jaw forward on an artificially created overbite - premolars where extracted in lower jaw - and a genioplasty).

To me it looks this woman has the same problem; if they would have rotated too much CCW of course she would have got a better chin, but her upper jaw would have looked very messed up (upper teeth would have been proclined, and could have ended up protruding through the lips).

So it is true that sometimes you are limited by the skeleton, but actually the results in the pictures are good, within normal values. Take notice that as opposed to men, women look better with a slightly reccesive chin, while in men we expect a straight profile, even a slightly concave one (with protruding chin).

I've said it elsewhere, but the notion that men and women have different structural ideals concerning the jaws (i.e. that men should have more relative width at the jaw angles and more protruding chins while women look better with slightly recessed chins and rounded mandibular angles) isn't true at all.  I see this being written everywhere and I don't know who came up with it, nor do I understand why people believe it.  Search pictures of the hottest women and they have strong, defined jawlines.  It has nothing to do with masculinity, testosterone, etc.