CW Rotation vs. CCW Rotation

[jcan7]

Hi All,

I have been doing a lot of research on how a clockwise (CW) rotation of the upper jaw affects the face vs a counterclockwise rotation (CCW) of the upper jaw and I can't seem to find exact answers.

From my research it seems that a CW rotation can shorten the face appearance and add to the cheek area. Can someone explain to me how this works exactly? Or am I even correct with my findings?

Also, how does a CCW rotation affect the face?

Thank you!

[molestrip]

CW rotation brings the rear of the maxilla up, CCW rotation brings it down. By itself, it does nothing to the face. If you have a posterior open bite, then it could close that bite. The more interesting case is when you have a normal bite. In that case, moving the maxilla like that also typically results in moving the mandible the same amount to maintain occlusion. In that case, CCW steepens the jaw line while CW lengthens it. The fulcrum is the upper incisors I believe so the chin projection will be a tad more forward with rotation resulting in a slight shortening of the lower 3rd. In long faces, because excess horizontal growth was vertical instead a sliding genioplasty may also be necessary to make you really normal, though under 3mm isn't detectable by others.

[terry947]

doesnt CCW shorten the lower third of the face because the mandible short of rotates forward slightly, making the lower third look less recessed? also I though CCW rotation was done by a wedge shaped impaction, causing the front to rise upwards making the occlusion less steep. It doesnt make sense to be that they'd drop the posterior of the maxilla... wouldnt that technically lengthen the face because now you have to add grafts into the spaces that were created?

[notrain]

CW Rotation makes the face longer.

CCW Rotation makes it shorter.

[Nataliepryor]

That has to be right, because I'm getting CCW and have longish face shape. Should look hot when it's all healed  ...kidding

[jcan7]

Does a CW rotation manage to fill out the cheeks at all though?

And I can see how a CCW rotation would shorten the face but how does a CW rotation lengthen the face? Since the front part of the upper jaw remains in the same position, I figured there wouldn't be much of an affect on face length.

[molestrip]

@jawbone It's a good point, I shouldn't have said the back. It's the net movement that matters. However, you're wrong about the CCW with no impaction, the main reason being forgot to take into account forward movement and you're assuming that one started with a stable occlusion. In a case like mine, I have a normal maxilla and a long mandible, hence the open bite. First they're going to bring both forward and rotate the mandible up to meet the maxilla. Then they're going to do a CCW rotation on the posterior maxilla to allow an even greater rotation of the mandible while keeping the anterior maxilla unchanged in vertical position. To really fix the deformity, a sliding genioplasty is necessary to restore the vertical height of the mandible.

[terry947]

oh so molestrip your occlusion is basically flat? I forgot what your ceph looked like.

I guess in my case since my occlusion is sort of steep they have to impact the front to rotate it and make it look more straight?

[molestrip]

Yes my maxilla is flat, my mandible is long. If it weren't for the sleep apnea, then they wouldn't need to touch the maxilla. I was given that option actually, to CW rotate the maxilla to close my open bite (BAD idea, I know). A BSSO to close the open bite might even be enough to cure my sleep apnea for a while, given that my airway is 9mm at smallest right now.

[strongjawman]

I think both can lengthen or shorten face, it depends on whether you do downgrafting or impaction of the maxilla in conjunction with CCW or CW rotation. If you are doing CW rotation by moving the back of the maxilla up, that is shortening the face. If you're doing CW rotation by moving the maxilla down at front... that would lengthen the face.

CCW rotation with no impaction would lengthen the face, with impaction it's shortening the face.

If impacting shortens the face, then why would no impaction lengthen the face? Sure it would remain neutral, no?

[kjohnt]

If impacting shortens the face, then why would no impaction lengthen the face? Sure it would remain neutral, no?

You're correct per my understanding.

CCW w/ anterior impaction = face shortens
CCW w/ posterior downgrafting = neutral
CW w/ anterior downgrafting = face lengthens
CW w/ posterior impaction = neutral

Of course, combinations of impaction + downgrafting are likely.  It's tough to find actual medical papers describing the process.

[PloskoPlus]

Of course, combinations of impaction + downgrafting are likely.  It's tough to find actual medical papers describing the process.

Isn't that what A&G do all the time - anterior impaction, posterior down grafting/

[notrain]

Isn't that what A&G do all the time - anterior impaction, posterior down grafting/

yes, and that is because it nets the greatest possible ccw rotation effect while at the same time being the easiest possible surgical techique for achieving this. It also makes it possible to reduce the amount of necessary posterior downgrafting. Way back when I browsed for before and afters, I noticed that class 2 LFS always had the best CCW results. Now I know why: Their anterior excess allowed for a huge CCW movement without going beneath that critical face height threshold.

[molestrip]

Anterior impaction isn't a given. Long face syndrome comes in two flavors, very steep planes where the anterior is in the right spot or mild-moderate planes with gummy smiles. It only makes sense to impact when a gummy smile is present.

[strongjawman]

Anterior impaction isn't a given. Long face syndrome comes in two flavors, very steep planes where the anterior is in the right spot or mild-moderate planes with gummy smiles. It only makes sense to impact when a gummy smile is present.

Interesting. So if ones gum show is ideal, but with a steep plane, does this mean CCW with no posterior impaction? Would this also mean more rotation of the mandible for the teeth to meet properly?