Class II elastics question - just teeth or jaw too?

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#1 Post by **Lisa65** » Wed Aug 08, 2007 6:39 am

I've tried looking this up but without success, so I'm hoping Meryaten's research or somebody like Rory might know for sure.

When I put in my class II elastics, my lower jaw feels like it's being pulled forwards so that my teeth "want" to bite together differently. Is the aim of elastics purely to move the teeth in relation to each other, or are they also intended to retrain the jaw muscles? I seem to remember reading somewhere that when you have a class II malocclusion, the lower jaw muscles get kind of lazy and that can make the mandible sit in an even more retrusive position. My profile looks better with the elastics in (I have more of a chin), so will this gradually become the norm once I've worn them for a while?

Hope somebody knows the answer.

#2 Post by **PoliGirl** » Wed Aug 08, 2007 8:16 am

Oh I hope a Dr. can answer this because I have the same question and have seen conflicting reports.

#3 Post by **Clo** » Wed Aug 08, 2007 9:39 am

No, this won't become the norm. It would be fanastic though, wouldn't it ? It
would be an alternative for a BSSO in cases that are not that bad. I had class 2
elastics for more than 2 years, full time wear and also very heavy ones. I too
experienced what you tell, but once they were removed, and after some "settling",
my jaw was there again were it always had been. And I also lost all improvement
of what those elastics achieved, one reason why I now have to have braces again.
But that is a whole different story ...

#4 Post by **SandraJones** » Wed Aug 08, 2007 10:42 am

The topic of class II elastics came up in a recent thread:

viewtopic.php?t=14198

I think the answer to your question is: both.

For an adult, they will affect both teeth positioning (upper and lower) and also mandible position, but not mandible length.

I think the mandible is very accommodating and can will "learn" to close into the best position for dental occlusion, with certain limitations of course.

#5 Post by **Lisa65** » Wed Aug 08, 2007 11:28 am

Thanks for finding that post Sandra, I had a feeling there'd been one fairly recently. At the age of 42 my lower jaw certainly isn't going to grow

I guess class II elastics and other bite jumping devices do different jobs depending on whether the jaw is still actively growing or not.

I wonder if the type of class II (whether it is skeletal as in Clo's case or mainly dental as in my case) would influence the efficacy or the outcome? My ortho originally said that if I didn't want implant screws or if they rejected, then using class II elastics and IPR he would still have been able to get me a reasonable result from treatment. So that was what got me wondering as to how much class II elastics alone could accomplish in a dental class II malocclusion, using the "bite-jumping" effect.

#6 Post by **SandraJones** » Wed Aug 08, 2007 12:10 pm

This has been on my mind a lot !! I don't really want my lower teeth pulled forward, but in order to pull the upper teeth back, what else can you use for leverage ? Implants sound nasty but that's probably the best way to do it. Or headgear ? Is there such a thing as class II headgear ? So much to learn !!! I spend hours and hours reading and I still have so many questions. My poor orthodontist is going to get hammered with them.

I've decided since while seeing her she will be working on my braces much of the time and I won't be able to talk, I'm going to type up my questions and have her look at them and tell me the answers while she's working on me.

I just hope I don't drive her crazy.

#7 Post by **Lisa65** » Wed Aug 08, 2007 12:27 pm

Anchorage is certainly a problem, as without a fixed anchor, all movement is going to be subject to Newton's 3rd Law.

Cervical or high-pull headgear can be used to pull the top molars back using the patient's head as an absolute anchor. A lot of people are reluctant to wear it though, and it needs to be worn as prescribed otherwise it doesn't work. Screw implants are another option as they do not need the patient to be compliant, plus there's the aesthetic advantage.

I just got an e-mail back from my ortho. I sent him my question earlier and he's usually pretty good at answering anything I ask him. I quote (my underlines)

"Dear Lisa, the class II elastics are mainly intended to work on moving the teeth through the bone, in your case to move the lower molars forwards to close the lower space. There is of course a smaller and unpredictible effect on the jaws, but generally this is not the intended action. Please do not be tempted to over wear the elastics as this will simply move all of your lower teeth forwards in the jaw once the lower space has closed and the lower incisor gum may be harmed by this. As you have upper implants in the elastics will have no effect in moving the upper teeth backwards in the jaw. Another reason not to over wear them."

Question answered, I think.

#8 Post by **SandraJones** » Wed Aug 08, 2007 1:47 pm

Hey Lisa, I'm looking at your blog and your pics from the beginning of treatment show a teeth arrangement much like mine. One lateral incisor pushed back ... for me the other lateral incisor is advanced, while yours was in fairly good position. I need to thoroughly read all of your posts because I can see at a glance that you have TONS of great info in there ! I might have some questions for you later, I hope you don't mind !

(Update: I'm on page 6 and can't turn away from it !! This is better than a Harry Potter book !) (Not that I have read any Harry Potter books, but I've heard that they are engrossing.

)

#9 Post by **LynnHowell** » Wed Aug 08, 2007 1:59 pm

When I had elastics, I was told that it's normal to feel the jaw muscles being pulled and that's what they were working toward.

After you've worn your elastics long enough (and the muscles have been 'retaught') you won't really notice they're there and you won't have that pulling sensation. On the upside, it should bring your chin out a little more and make your profile better.

#10 Post by **Lisa65** » Wed Aug 08, 2007 10:49 pm

I knew they moved the teeth - what I was hoping to find out was whether they also had an impact on jaw positioning.

#11 Post by **Clo** » Thu Aug 09, 2007 12:07 am

You know what, Lisa, I really like your ortho. I think he is very skilled. His
approach is what I like the most. Can't you lend this doc to me from time to
time ? I know what he means by this unpredictable effect on the jaws. At
least I think that. It is wear or a deformation of the condyles of the jaw joint.
Making this joint work differently. The jaw specialist who saw my scans told me
this is a bit what I have now. Believe me, as your ortho said it as "not the
intended action", this is not what you are looking for. But you are lucky. I
know these screws were sometimes not easy, but they are far more effective
than elastics will ever be. It would not surprise me at all that, maybe within
many years, orthos will not use elastics anymore to do big movements or create
a bite. They are great for minor movements, and to create that final good occlusion
like box elastics do. But moving whole arches, nah .... Just my opinion, soon to
be known as Clo's Ortholaw 1 ...

#12 Post by **Lisa65** » Thu Aug 09, 2007 5:07 am

Clo, I wish I could lend my ortho to you, or clone him and send the clone to Belgium for you. I told him a little bit about your case and he was shocked at the damage that's been done to your bite. The screws were sometimes difficult to deal with, but at least they have achieved the desired movement without causing damage to my jaw joint or messing up my bite. Hopefully the bone anchors will work for you.

I am lucky that my teeth move fast and after 2 nights of wear I can tell the lower gaps are already smaller.

Meryaten, I also wonder about the use of bite-jumping appliances in adults. I asked my ortho a while back about ways of reducing the class II and asked if something like a Herbst would do the job, and he said that once jaw growth is complete then the use of bite-jumping devices is really of no help.

#13 Post by **eggraid101** » Thu Aug 09, 2007 7:12 am

I would agree that Class II elastics (or class III elastics) have most of their effect on the teeth rather than the jaws. There may be some change in the jaw, but it is very small, and would have a correlation with the length of time you wear your elastics, too. Even using a Herbst or another appliance like a Herbst only has a small effect on the jaws; there is still a lot of change in the teeth with those as well, even in a kid. Keep up the elastic wear, it sounds like you're doing exactly what you should be doing!

#14 Post by **Bluerain** » Sat Aug 11, 2007 2:48 pm

I have class 11 which is mainly from dental not skelatel.

We are currently try to pull back the top teeth to close the gap (overbite/deepbite which is isn't that bad). The elastics are attached to bottom back m molar and go to top canine where a loop was made so as to put pressure on entire wire therfore puuling back all the teeth at once as far as is allowable by the bone up there.

Someone mention that both top and bootom will move and i guess that is true but... The bottom will move very little as 2nd lolars are the biggest teeth and move much slower.

Think of it this way..it's easier to push a smaller blocks into a bigger ones(Top teeth ) then a bigger blocks into a smaller blocks.(Botton teeth)

I'm afraid i'm not getting alot of movement (Some but small) due to the fact that i clench my teeth (Not grind) almost all my waking hours (Most). Which cause the bottom teeth blocking the top from moving back due to my deepbite/overbite.

I think if i had a button behind top center teeth this would help by stopping me from deepbite until they moved back.

I had anchors (2 screws with abbutment /fake tooth attached)) one on each side (Top) where wisdom teeth use to be. The reason i had this i refused to get any teeth pulled (Premolars) to make room. Had wisdom teeth removed and top second molars to make room and use anchors to to make space by pulling into space created by removing molars and wisdom teeth. When all is said and done anchors /implants will be use to replace molars that were pulled.

The reason i bring this up i was wondering why aren't they still using my anchors to pull back top teeth to fix deep/overbite using the loops like they have on the canines on top?

I have to bring this up Tuesday .

Blue

Sat Jul 31, 2010 11:10 am

I know I'm bringing this back, and I'm sorry, but I found some studies about actual jaw movements and new profile changes that I thought you guys would find interesting.
http://www.ormco.com/index/damon-casest ... traction-2

Both of these adult patients got profile changes, and one of the studies includes a report 3 years later which shows that there wasn't any relapse.