case 2 prompt 2

[Chad Carter (Course Director)]

Good thoughts!

So as a skeletal objective to the maxilla we have a spectrum of options:

In the growing patient we can try growth modification – holding (vertical and/or horizontal with various levels of force), reverse pull headgear, or the “headgear effect” that we get from some appliances.

In the non-growing patient we decide surgical or non-surgical.

So first question – is the protrusive or not? Based off N Perp A and the cranial base adjusted SNA, I agree that it is protrusive.

The second question – do we treat it? Is it one of our objectives? In order to answer this I consider the patient’s concern, facial esthetics and surgical options. For this patient, I like the rough esthetics of the maxilla, it is ethnically appropriate and harmonious with her face.

Surgically there is not a great option to move the maxilla posteriorly in the AP. There is an anterior segmental osteotomy procedure that is seen mostly in Korea and there is a premolar transpalatal osteotomy discussed in Proffitt’s surgical textbook. I’ve not found an oral surgeon that does either of these procedures…and I’ve had a couple cases where it could have helped! So for these reasons in the AP direction with the maxilla it’s conventionally either hold/leave it alone in the AP or Advance it.

(Side note here, in practical terms even if you say “hold” in the AP and you are downfracturing the maxilla for some other goal (rotation, cant, or expansion) then the surgeon can’t place it exactly back in the same AP – the pterygoid plates will get hung up and it’s pretty challenging to clear the bone requried. So even in a “hold” situation once the down fracture happens your going to have about a 2mm advance)

[Joti Kaler]

I have a question for case 1:

for treatment options- I don’t follow. Expander,TPA, TADS, surgery, CAT. Are these all separate options? I could see expander+TPA + TADS as one option? In general when they as for options should we be saying a non surgical and surgical option? For this I would go TADS due to age and the article supports it as long as you accept LAFH.

A general question. Narrow maxilla vs Maxillary transverse discrepancy. Is it the same? if not when do you use what? TY

[Chad Carter (Course Director)]

When I see a question asking about options I simply think of it like I’m talking to the patient (and parent if applicable). I’m giving them options of things I can do to “win” for their smile. Some of them will definitely be combinations for the best option. I could really want to do TADs + CAT but they say “No way! I’m not having no screws!”. So then some other combo. I’d treat options as your moment to shine with creativity. How many ways could you treat the case presented to ABO standards?

“A general question. Narrow maxilla vs Maxillary transverse discrepancy. Is it the same?” – Yes when I see a Narrow maxilla it’s deficient in the transverse dimension – then I figure out how I’m going to treat it.

Great work everyone on the weekend studying!

[Joti Kaler]

Let me better say that. If i write down the answer “narrow maxilla” instead of “deficient transverse dimension” are they interchangeable?

[Chad Carter (Course Director)]

I would stick with “Maxillary Transverse Deficiency” as a standard diagnostic term.

Good clarifying question!

[Leah Stetzel]

Based on prompt #1 (skeletal diagnosis), I thought our skeletal objectives would mirror the diagnosis. For example, I thought the objectives would include posterior maxillary impaction, as we noted that PNS was lower than ANS in the diagnosis. I also thought we would hold the mandible in its AP position (mandible was normal in AP dimension), but it says to advance the mandible? Can you explain?

Thanks for all of your help! I know I’ve been a lot!

[Chad Carter (Course Director)]

Leah (sorry for slow reply – been down at the conference for this week),

You are right objectives will follow the diagnosis but they are also linked a bit to treatment plan so I think the that Prompt #2 could be improved by saying “What are the skeletal treatment objectives for a surgical/orthognathic plan?” – What do you think about that that?

Posterior Maxillary Impaction will reduce tooth display as well. It’s a mild enough tip and she doesn’t have posterior VME on animation so I would personally not do it.

The mandible has to advance to correct the Class II because we can’t “set back” the maxilla to correct the Class II. (which is ethnically appropriate for esthetics as well)

Keep the questions coming folks! Discussion is great,

All the best,

Carter

[Leah Stetzel]

Hello,

Some more questions of Case #2

1. Could it be argued normal maxilla and retrusive mandible? Considering ethnic variations?

2. When a question asks to “critique” an outcome, I noticed that the answer included both things done well and also not well. I was thinking critique would mean focusing on the poor outcomes. Just like a “problem list” is different than a “diagnosis”?

3. Could you say “anteriorly rotated palatal plane” instead of “posterior tilt palatal plane”

Thank you

[Chad Carter (Course Director)]

1) Absolutely could say normal maxilla based on ethnicity.

2) A critique can include positives and negatives in my opinion – did you acheive your goals? what still needs done?. A sample question the ABO has provided is “What could be done to improve the outcome/CRE score?” – in that situation I would just include negatives for what needed further correcting and how I would plan to do it.

3) I understand your description of the palatal plane rotation. That’s why the board is graded BY orthodontists – exactly to help understand all the terms.

-Carter