Author Topic: Looking for advice on CBCTs  (Read 1453 times)

accgram

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Looking for advice on CBCTs
« on: November 20, 2021, 11:29:34 AM »
Reposting from the aesthetics section for more visibility as I am also doing this for functional reasons. I would like to get input on movement recommendations so I am as informed as possible for my upcoming consultations.

https://imgur.com/a/RFlBpOU

Note: The web ceph is done by an AI, so I am not sure if it is 100% accurate.

GJ

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Re: Looking for advice on CBCTs
« Reply #1 on: November 20, 2021, 01:27:08 PM »
Are those wisdom teeth? What is the plan there - are you going to have them extracted prior to surgery?

In terms of movements, this is a rare case where I think extracting two lower premolars, closing the space orthodontically, and then advancing the lower jaw only makes the most sense. The reason I say this is your maxilla does not look to be in a bad position, and your bite plane is fairly level. This would eliminate unaesthetic changes around the nose area, too, which are very common when moving the maxilla.
Millimeters are miles on the face.

accgram

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Re: Looking for advice on CBCTs
« Reply #2 on: November 20, 2021, 01:44:18 PM »
Are those wisdom teeth? What is the plan there - are you going to have them extracted prior to surgery?

In terms of movements, this is a rare case where I think extracting two lower premolars, closing the space orthodontically, and then advancing the lower jaw only makes the most sense. The reason I say this is your maxilla does not look to be in a bad position, and your bite plane is fairly level. This would eliminate unaesthetic changes around the nose area, too, which are very common when moving the maxilla.

I do have some wisdom teeth, however not all of them are fully grown in, although they don't cause any problems. I would rather have the least extractions as possible, are premolars getting extracted required for BSSO? I understand that sometimes these will have to be done no matter what to get the required movements. Also is there a good way to tell how much vertical movement one should get for genioplasty?

As for the maxilla, what do you think about lower lefort cuts that don't impact the nose? Would whatever few mm maxilla movements be worth it aesthetically? Thanks.
« Last Edit: November 21, 2021, 01:12:45 AM by accgram »

kavan

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Re: Looking for advice on CBCTs
« Reply #3 on: November 20, 2021, 04:29:29 PM »
Are those wisdom teeth? What is the plan there - are you going to have them extracted prior to surgery?

In terms of movements, this is a rare case where I think extracting two lower premolars, closing the space orthodontically, and then advancing the lower jaw only makes the most sense. The reason I say this is your maxilla does not look to be in a bad position, and your bite plane is fairly level. This would eliminate unaesthetic changes around the nose area, too, which are very common when moving the maxilla.

I tend to agree with your suggestion. I've drawn a white TVL ('true vertical line') passing through the base of nose which makes it easier to see the mandible and chin point is too far behind that line relative to maxilla. The ANB conveys that too and also class 2. So it does basically look like a case where the overjet would need to be increased (with braces) via 'bucking out' the front teeth more and pushing backwards the lower front teeth (extraction of pre-molars to make room for the push back). That looks to yield the space to move the lower jaw forward, quite possibly in single jaw surgery.

NOTE: AI programs are pretty accurate in identifying the POINTS (landmarks in the bone), connecting the points to make lines or 'planes' and connecting the lines to form ANGLES and comparing those distance relationships to normative ones to see what the deviations are.
Illustration included in this post.

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accgram

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Re: Looking for advice on CBCTs
« Reply #4 on: November 21, 2021, 01:05:18 AM »

I tend to agree with your suggestion. I've drawn a white TVL ('true vertical line') passing through the base of nose which makes it easier to see the mandible and chin point is too far behind that line relative to maxilla. The ANB conveys that too and also class 2. So it does basically look like a case where the overjet would need to be increased (with braces) via 'bucking out' the front teeth more and pushing backwards the lower front teeth (extraction of pre-molars to make room for the push back). That looks to yield the space to move the lower jaw forward, quite possibly in single jaw surgery.

NOTE: AI programs are pretty accurate in identifying the POINTS (landmarks in the bone), connecting the points to make lines or 'planes' and connecting the lines to form ANGLES and comparing those distance relationships to normative ones to see what the deviations are.
Illustration included in this post.

Would getting wisdom teeth removed create enough space to move the lower jaw? If I can choose between wisdom and pre molar I would like to choose whichever one has the least effect on my face, if any.

GJ

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Re: Looking for advice on CBCTs
« Reply #5 on: November 21, 2021, 06:48:52 AM »
No the wisdom teeth shouldn't have any effect. Maybe some short-term swelling.

Two lower premolars shouldn't have a dramatic effect, either. Upper bicuspid extractions are worse. It's never ideal to extract bicuspids, but it seems like a rare case where it's the best option. Make sure to say nothing about this on your consults so you don't color the surgeon's opinion. You want objective opinions from the people analyzing you in the flesh. We're just going by what we see in 2D on a computer.
Millimeters are miles on the face.

kavan

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Re: Looking for advice on CBCTs
« Reply #6 on: November 21, 2021, 11:28:39 AM »
Would getting wisdom teeth removed create enough space to move the lower jaw? If I can choose between wisdom and pre molar I would like to choose whichever one has the least effect on my face, if any.

Removal of wisdom teeth is done to create a 'SAFE SPACE' for the surgeon to perform the BSSO cut. It's done to prevent a BAD SPLIT (unfavorable fracture) to the mandible.

Removal of the lower pre-molars is done to make SPACE for the lower front teeth to be pushed backwards with braces, which in turn, creates MORE DISTANCE for the surgeon to advance the lower jaw forward.

Now, those 2 KEY pieces of information should suffice to address your own basic question of 'IF' you can choose which teeth to extract.

That said, ASSUMING your GOAL is to address the RECESSION of your lower jaw, what is the answer to the following question:

'IF a surgeon wants the wisdom teeth in lower jaw to be removed to PREVENT a BAD SPLIT when performing the BSSO and also wants the (lower jaw) pre-molars removed in order to create more distance to advance the lower jaw forward, do you have a choice as to which teeth he should remove?

YES or NO.
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accgram

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Re: Looking for advice on CBCTs
« Reply #7 on: November 21, 2021, 12:19:22 PM »
Ok, thanks to both of you for the info. If they all say I need to remove the premolars and wisdom I understand that there is no way around it and has to be done. I will make sure to consult multiple surgeons to get a common general consensus on them.

accgram

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Re: Looking for advice on CBCTs
« Reply #8 on: December 14, 2021, 08:15:32 PM »
Does anyone know how much mandibular advancement after decompensation I can expect with about 3-4mm of overjet? Also, is there a good way to measure how much vertical/horizontal genioplasty would be needed?