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I’ve been thinking, if the mechanism of allowing saggital expansion with MSE is the distraction of the circummaxillary sutures, wouldn’t having more distraction over time allow for more saggital expansion for adults?
By increasing the time of distraction by turning the MSE screw forward then backward over more time (though more forward then back), I would suppose that doing so, while using facemask, would allow for more time having the sutures open thus more forward (saggital) movement.
Suppose one needs 10mm transverse expansion using MSE, and needs as much forward expansion as possible. Instead of turning the screw forward over X number of weeks, after reaching 2mm, reverse at the same rate back to 1mm, then expand again at the same rate up to 3mm, then reverse to 2mm, and repeat until 10mm is reached. The X number of weeks would end up being about 2X.
I remember Won Moon said that adults could expect as much as 3mm saggital expansion by combining MSE with facemask. Ideally, could combining expansion and contraction with MSE result in potentially more than 3mm?
I am still looking for one well documented case of MSE + FM treatment. I will be getting MSE soon so maybe it will be me. As for your question, it would be hard to test because everyone expands at different rates, but theoretically it seems things would be looser for longer.
I’m also curious to read this citation, which suggests that alternating between expansion and constriction could help disarticulate perimaxillary sutures:
Wang YC, Chang PM, Liou EJ. Opening of circumaxillary sutures by alternate rapid maxillary expansions and constrictions. Angle Orthod. 2009;79(2):230–234.
http://www.angle.org/doi/pdf/10.2319/031208-141.1
The study, alternating between expanding and constricting the midpalatal sutures of cats as an animal model, found that sagitally-running circummaxillary sutures disarticulated significantly more than coronally-running circummaxillary sutures that required more than 5 weeks to increase opening. This makes sense that opening the midpalatal suture sideways would induce separation of other sutures around the maxilla sideways, but would be less effective at separating circummaxillary sutures in a forward direction.
Applies to less sophisticated forms of MARPE. MSE does this just fine without.
For about a month, I’ve been alternating between weeks of turning backward and forward after completing all of the turns on my MSE and not being satisfied with my protraction results. So far I haven’t noticed dramatic change. The most obvious case I’ve seen of an adult who treated his class III malocclusion with MSE+FM incorporated some weeks of reverse turning, but that was just one case report and there’s no consensus about it’s utility. Dr. Ting mentioned using some backward turns in one of his interviews with JawHacks. I’ve been waiting to recommend it here until I see what it does for me. I think it might be worth trying, but it’s not necessarily going to pop open all of your circummaxillary sutures or give you the kind of results seen in children.
@apollo do you mean that you don’t get much expansion or forwards grow? I thought the MSE appliance was only for the expansion?
I know I’ve read articles from the MSE gurus (Won Moon, Peter Ngan, etc.) in the past about how using a facemask (a.k.a. reverse headgear or facebow) while actively using MSE in adults has resulted in measurable forward protraction (in addition to the sideways expansion you get from the MSE by itself). Anyone know where such articles could be found?
@mr_man So let’s say one were 14 and we planning MSE+FM for substantial increase in maxillary development in the saggital and tranverse dimensions and were class 2. Would that be a promising treatment to fix the maloclussion and have profound efffects functionally and aesthetically? Thoughts?
I know I’ve read articles from the MSE gurus (Won Moon, Peter Ngan, etc.) in the past about how using a facemask (a.k.a. reverse headgear or facebow) while actively using MSE in adults has resulted in measurable forward protraction (in addition to the sideways expansion you get from the MSE by itself). Anyone know where such articles could be found?
I’ve been earnestly looking for such articles also, haven’t found much tbh
I think at age 14, you’d have quite a good chance of achieving both. I’m no expert but I’m basing thjd on what I’ve read
@mr_man could you expatiate you seem pretty knowledgable. With the fm anchored in the the mse how much forward protraction do you think I could achieve. How would I encourage my mandible to advance with my mandible to fix my class 2.
I think at age 14, you’d have quite a good chance of achieving both.
Expatiate? Isnt age 14 a bit too late do you think or no.
@apollo do you mean that you don’t get much expansion or forwards grow? I thought the MSE appliance was only for the expansion?
On its own, the MSE gives transverse expansion, plus it often gives some slight forward expansion. We discussed why this might be in this thread ( https://the-great-work.org/community/main-forum/mse-asymmetry-and-protraction/ ). In adult cases, facemask protraction can help give a little more forward expansion, but not much. The alternating expansion and contraction protocol is intended to further mobilize the sutures to facilitate protraction, but there’s not a lot of evidence that it gives dramatic results. In my case, the MSE successfully gave me good transverse expansion and I think I got a couple millimeters of forward expansion, but I really need a little more protraction to get my occlusion right. I’ve been experimenting with alternating expansion and contraction for a few weeks now. I can’t tell if it’s doing anything yet.
I know I’ve read articles from the MSE gurus (Won Moon, Peter Ngan, etc.) in the past about how using a facemask (a.k.a. reverse headgear or facebow) while actively using MSE in adults has resulted in measurable forward protraction (in addition to the sideways expansion you get from the MSE by itself). Anyone know where such articles could be found?
Dr. Moon mentions the use of MSE+FM in mature patients in the article “Class III treatment by combining facemask (FM) and maxillary skeletal expander (MSE)” and in a couple lecture videos, but I’m not aware of any research studies.
Maybe that’s what I’m thinking of; perhaps there are no actual research papers on the topic.
I would think that 14 years old, while too old for the tooth-anchored expanders (which one of my children actually used at age 9), is still rather young for MSE. My skeletal bones didn’t stop growing until about 19, so I’d imagine that whatever bone expansion an adult would get with MSE, a 14 year-old would get more. I would guess maybe something like 4mm (just guessing).
I actually don’t have any experience yet with MSE. If you read some of my older posts, I talk about how I had a Lefort I (upper jaw expanded and advanced) and bsso (moved lower jaw slightly back) when I was 19; now I’m almost 44. The operation improved my forward and transverse deficiencies, but despite that, I’m still deficient in both (10mm transverse and betwween 5 and 8 mm forward).
The last place I consulted with does perform MSE in general, but they said it wasn’t an option in my case. They want to do a 2-piece Lefort I but said they probably can’t expand enough horizontally to reach the same width as my lower arch. I don’t necessarily want to proceed since I don’t want to go through all of that unless they can expand enough horizontally.
That is why I want to find a place that is willing to use MSE on me, so that I do have enough width to my upper arch and can decide later if I want to do a simple LeFort I advancement. Plus, I’d like to try MSE+FM to see if that at least gives me enough advancement to be somewhat satisfied.
I don’t know much about protraction of the lower jaw (which I don’t need anyway) but worst case you could do a bsso advancement when you’re 18 or older, which I found was not too bad of a procedure.
@mr_man when do you need protraction for thr lower jaw?
And for a BSSO advancement they remove the back molars of the lower jaw right but why they do that why can’t they just keep them and do the surgery or does that create an under bite?
I don’t know the answers to either of those, but in my case my lower jaw is already plenty big. I already had removed my wisdom teeth so no extractions were done in preparation.
My SNB angle is 83° (it’s only 78° for the SNA, for the upper jaw). This is all after my 1997 operation. My SNB used to be more than 83° and SNA used to be less than 78° (I wish I could find my old cephalometric analysis from before 1997 but don’t have it).
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