I am a full-time faculty member at the University of Illinois at Chicago. I'm an orthodontist, but for the past more than 10 years, my passion has been in dental sleep medicine. So I enjoy doing both. And it's really an honor to be invited to speak on both of my, like my, essentially what I do on a day-to-day basis. So I would like to make this as practical as possible. And at the end, you know, we'll have enough time for questions. So for the objectives that were provided for me at the end of this lecture, I would like for you to be able to discuss the expectations of known side effects with patients going through oral appliance therapy. I'd like for you to be familiar with individual patient risk for those dental changes and have some strategies under your belt to counteract any device forces and monitor any changes anticipated. I also would like to make it clear that I have nothing to disclose. All right, so what is the first thing we do whenever we provide oral appliance therapy for our patients? One of the first steps, as you all know, is obtaining an informed consent, right? And in this sheet that is, thankfully provided by and included in our AADSM membership, this part that I highlighted over here actually talks about these long-term side effects, actually short-term and long-term side effects are all outlined in this document. Therefore, we need to be familiar with them and we need to be able to discuss them with our patients at the beginning of treatment. This not only prepares us, but prepares our patients also and sets their expectations about what to expect. I have to tell you that this topic is near and dear to me because every time I attended, like in the past when I was new in dental medicine, every time I attended a CE course on this topic, the orthodontist in me always asks, well, if there are side effects, if there are dental changes, then why are we doing it, right? And is there a way to minimize this or to stop this from happening, right? I want the teeth perfect, I want the perfect class one occlusion, good overbite and overjet. What are you telling me here that there's no, there's no way to avoid this, right? Essentially, and every time I ask that, the answer is always, well, obstructive sleep apnea is a very serious disorder. And so what will you choose, right? Perfect dentition or, you know, longer, a longer life essentially is everything that was told to me each time I brought up the issue. And so I'm at peace knowing that there is, there will always be side effects, right? So that is, you know, that saying, the one thing constant is change. And so tonight we're gonna talk about what these changes are, that way we're all on the same page and then I will walk you through what I look at whenever I treat a patient for oral appliance therapy. So the first thing I wanna do is to familiarize you with how these appliances work, right? So we have all been conditioned to explain it in this simple manner of the oral appliance moves the lower jaw forward and because the tongue is the cause of the obstruction a lot of the time, and the tongue is connected to the lower jaw. Therefore, when you move the lower jaw forward, you're also advancing the tongue. And there is nothing wrong with that explanation. It's actually, you know, it makes sense and it's very, very straightforward, especially for a patient to understand what this appliance is doing. But there are a lot of nuances. The airway, as you know, is a collapsible structure and there are a lot of other parts at play, not just anatomy. But for tonight, we'll focus on the side effects, on the dental side effects. So how appliances work. Let me bring you back to me as an orthodontist, me as a professor. We usually, one of the biggest or toughest subjects in orthodontic residency is biomechanics, right? It's a discussion essentially of physics, right? The physics of tooth movement. And so in order for us to understand how appliances work, a lot of times we draw force diagrams, right? For example, this is a class two elastic setup. And for a class two, if we have a big overjet, our goal is to decrease that overjet. And so you can see here how we are pulling the upper teeth backwards and pushing the lower teeth forwards in order to correct that class two. But it's not just these AP or anteroposterior force vectors that are at play. If you remember, there is for every force, there is a corresponding moment of the force. So that's the turning tendency. So if you can picture this force going back as the elastic is pulling backwards, there is a corresponding clockwise moment, which then results in a little bit of extrusion of the upper anteriors and a little bit of extrusion of lower anteriors. So I don't wanna bore you too much with all the biomechanics in orthodontics, but it's very relevant when we bring it back to discussing how these oral appliances work. This is a helpful diagram that I found. And again, here they are talking about the change in the pharyngeal airway space, right? When you compare without an appliance to with an oral appliance. And you can see these forces that we're talking about at work, right? So it's not just bringing everything forward, but there is this force. If we are using an appliance such as a HERPS appliance or a HERPS type sleep appliance or oral appliance, mandibular advancement appliance, then we can see here that there is a force that is exerted on the lower anterior teeth, pushing them forward. And there is also that corresponding moment which results in this intrusion or proclination and relative intrusion of the lower incisors. And similarly, we see, because the teeth are being utilized as anchors, right? There is in mandibular advancement devices, we are using the teeth as anchors. And so all the forces that we're exerting in order to pull the lower jaw forward is being felt by or delivered to the teeth, which is why all these points that I bullet pointed here, the magnitude, so the amount of the force, right? How much force are we applying? That has to do also with how much advancement we are making, what is the direction of the force that we are applying and how long are we applying that force, right? And for our appliances, usually these are lifetime treatment for our patients and we expect them to wear it all night, every night. And when we look at the design of all of these appliances, it's quite similar in the fact that they all want to, the goal is to move the lower jaw forward. And if we are doing that and we are using the teeth as anchor, then naturally we will see effects on the teeth. So just to, I promise you, this is the one last orthodontic slide. This is a cephalometric superimposition of someone who had used functional appliances for 20 years. So as you know, the HERPS is a type of a functional appliance, right? And so in orthodontic treatment though, the difference is the duration of use is within that average two-year treatment time. After that, we remove the appliance and then the teeth settle. So here the blue, or sorry, the black is the baseline. And then the blue is post-treatment. And then the red is long-term, right? So you can see how the blue here, this is, I guess, the most significant change that you see. There is proclination of the lower incisors as well as a relative intrusion of the lower incisors. So you can see, you can picture that happening when you are using a HERPS type or like an oral appliance, a mandibular advancement device, right? This is happening. Now, the difference between this and what we do in dental sleep medicine is that after a period of time, when we take out the functional appliance, the teeth are able to settle back to, so their original angulation, so you can see that here in the red, but it's a little bit different with oral appliances. And the other difference is that there is growth typically when we are using functional appliance. And so there are overlaying effects, but I just wanted you to pay attention to mainly the dental changes. So speaking of dental changes, what does the literature say about all these side effects? As you know, in the hierarchy of evidence, the best type of literature is the systematic review. And this one, so I only chose a few for tonight, but this one is one of the ones that I chose to discuss with you because in their systematic review, they had a strict criteria of only picking randomized controlled trials. So they only wanted randomized controlled trials that were going to identify side effects of oral appliances. And they only had six studies that met the systematic review criteria that they set or that they preset. And surprise, surprise, the most common side effects were dental. Was decreased overbite and overjet. They also said that the side effects pertaining to the joint were very limited and uncommon long-term. Short-term, sure they happened, but long-term, it was very rare. So that's why the bulk of our discussion is going to be on these dental side effects. I didn't want to discount the TMD side effects too quickly. So I also wanted to focus on or to mention this paper that was recently published. And it was a really well-designed study. So what they did was they randomized. So this group, and these are all very well-respected researchers in the field of dental sleep medicine. They had 64 subjects that they randomized into three groups, a mandibular advancement group, a CPAP group, and a placebo. And it's very rare to have this designed in like this way where it's randomized and controlled. So I really liked this study. And what they did was they did a temporal mandibular joint exam before treatment or at baseline and after six months of treatment. And they also had a questionnaire on mandibular function. And what they found was no significant differences among the three groups. They also showed or found a low frequency of those joint signs and symptoms after six months, regardless of the group. So that just kind of reinforces what this systematic review had told us, right? So I think by this time, we are all comfortable now focusing on mainly the dental side effects. So this group, Dr. Doff and colleagues, what they did was they actually had two groups of patients an MAD and CPAP, and they wanted to check the dental changes. So remember, these are the most common side effects are the dental changes. So this group wanted to focus on just that. And what they did was they studied tasks for both the mandibular advancement group and the CPAP group. And what they found was there was actually more of a significant change for obvious reasons, which we discussed earlier in the mandibular advancement device group, because you're using the teeth as anchor, right? And pulling the lower jaw forward. They did notice some dental changes in the CPAP group as well, but the more significant changes were in the MAD group. And then 10 years later, so it's very unique. Every time we read a paper at the very end, you will see a limitation of this is we need more long-term studies, et cetera, et cetera, et cetera. So it's very rare to find long-term follow-ups like this. And the same group did it and published it just recently. And they did a 10-year follow-up. Unfortunately, there is always that issue of subject attrition. So people move, things happen, so you can't call on the same number of patients. But they did get about 14 people from the MAD and 17 from the CPAP. And what they noticed was there were dental changes in both CPAP and oral appliance groups. So both exhibited, just looking at the chat. So both exhibited changes, dental changes, but it is larger in the MAD than in the CPAP group. So if you, again, using the same principle or the same way we were thinking about where are the forces going? Where are we, what are the devices or appliances attached to? You can imagine that the CPAP will also have some effect on the dentition or on the oral-facial complex. And so what they found was there was also some effect in the CPAP group. But again, it was much more significant in the MAD group. Dr. Pliska and his colleagues, this is probably the most cited paper when you talk about occlusal changes associated with oral appliance therapy. And that is because they had a significant N N or population study sample size. And they also had a long treatment time or treatment follow-up. So they had 77 subjects and they followed these people for 11 years after treatment. And they plotted the changes over time in different dental characteristics. And what they found was there was significant reduction of overbite and overject, which we already mentioned a while ago. And they also found that there was a significant reduction in lower anterior crowding, or if you translate that the other way, it means there is an increase in lower anterior spacing. So there is some spacing that happens in the lower anteriors. And again, if you think about the forces, if we, if depending on the appliance, so if there is nothing keeping the teeth together and the force vector is going in that direction, then you can definitely with a proclination of the lower incisors, then you can expect such changes. So there's no surprise here. What was interesting was the overbite or actually, sorry, the overjet continually decreased over time, but the overbite, the rate of decrease tapered off the longer the patient was in treatment. Okay, so, but either way for all of these, the changes were progressive in nature. So they continued throughout the use of the device. So it really tells us what to expect, right? Already in terms of mandibular advancement device use. Another interesting thing they wanted to see, are there any predictors? Can I know which patients will suffer the most side effects? And in their study, the demographics such as age, gender, or BMI were not at all related to the amount of side effects that they saw. Dr. Markland and her colleagues, they did a review recently and included all the studies that measured these dental side effects, mainly the overjet. And you can see here the treatment years, Dr. Pliska's study is here as well. Dr. Markland had a study long-term duration, but only had nine subjects, unfortunately. But you can see that the longer, so let's pick the largest sample sizes. So the longer the duration of treatment, right? So the greater the reduction in overjet, right? So I wanted to include that here so that you're aware, but so what, right? Okay, now we know there will be changes. We understand, we expect it. We know how to explain it to our patients, but so what? There is, and there are studies that have shown that the incidence of side effects actually affect compliance. So thankfully for these dental changes that I noticed or that I mentioned, I'm sorry, the patients are not really, their compliance is not really affected by those changes that I mentioned, but in more severe side effects, such as noises, jaw discomfort, and gingival discomfort, these side effects predicted the likelihood of non-compliance. So this study found that by placing a chip to monitor oral appliance use, and so it's just something to keep at the back of our head, right? So if something is not fitting right, just like if you have a pair of shoes that really hurt, you might prop it aside and not use it because it's uncomfortable. So in this case, we as dentists need to be aware of the side effects so that we can try and minimize or counteract them, if you will, so that we can preserve the compliance of the patient. All right, and going back to the predictors that we mentioned earlier, so Dr. Pliska tried to look at those demographics and found that there was no predictive value, but this group of Dr. Minagi studied a group of patients who went through treatment for an average of four years. This was the retrospective cephalometric analysis, and they saw that the fewer the number of upper teeth and the longer you are in treatment, so these are pretty obvious things, right? So we already saw that. So also the longer or the number of days per week of use, so in his case, he actually, even if he saw significance, he said he's not even counting that as significant because everybody pretty much wore the appliance every single day. So what they saw that was kind of significant or surprising for them was that when you had less number of maxillary teeth, then you had much more decrease in overjet. So if you think about what we mentioned earlier on having an anchor, right? So you're essentially subtracting from your anchor. So that means your side effects increase if your anchor is not as stable, and that's what they found in this study. And they also found that the more advancement that was done, there was also a corresponding decrease in overjet. So again, not surprising, but good to know. So the orthodontist in me, again, is thinking, now what, right? So I want straight teeth. I wanna keep those teeth straight. At the same time, I do like when patients come back and they say, oh my goodness, what a difference this makes. Right, and so how do I evaluate my patients after learning what I've learned, what I've just imparted to you? I look at the number of teeth available, right? We just talked about that. So you all know there is, you know, labs require X number of teeth, so at least 10 and arch for you to be able to get a good candidate for oral appliance therapy. We wanna look at the history, dental history of the patient, make sure the periodontium is healthy. So earlier, Dr. Braga and I had a little bit of a discussion regarding, oh, what if you have periodontally compromised lower anteriors? Then yes, they would not be a good candidate for oral appliance therapy, because if you looked at those force vectors, they were all going to be, that force is going to be transferred to those teeth. And if the teeth don't have a healthy support, then you are compromising them, right? So patient selection is very important. The type of occlusion, so I'm gonna show you a few patients later on. Type of occlusion, I mean, molar relationship, angle classification, class one, two, or three, right? So I look at that. I wanna know who's had orthodontic treatment, and I wanna carefully explain to them, right? Those things that we just mentioned, because I want them to understand and to expect change, and to know what change to expect. Also the presence of any pyrofunctional habits. So the most common ones would be bruxism or mouth breathing or tongue thrust. And then if they have any preferences, right? So I, you know, sometimes they do, sometimes they don't, but I typically show them a couple of sample appliances, explain how they work. And sometimes, most of the time, they will say whatever you recommend, but sometimes they'll surprise you by having a preference. A lot of times because they know somebody who's using X type of applying. All right, so let's see. For this patient, how do you classify this malocclusion? So this would be a class two division one, right? So if we are to advance the lower jaw, depending on the amount of protrusion the patient can accommodate, you will see that there is room to move the mandible forward, okay? So there is room to move the mandible forward. Therefore, there is this patient, you know, provided the jaw, the joint is healthy, the periodontium is healthy, this patient would be a good candidate for oral appliance treatment, taking into account the side effects we were talking about. Okay, so I could go on and on about oral appliance treatment, you know, orthodontic issues surrounding dental sleep medicine, but today I really had only, I was given, now I'm down to 10 more minutes. So I really wanna focus just on the dental side effects. So this patient would be a good candidate, right? We have room to move, we are okay proclining, and we have overjet, so it's okay to decrease that. Now, what if I had a patient whose occlusion was this type, right? So for those of you who remember ortho, it's class two division two, right? How would I, you know, push the lower jaw? Even if this patient was class two, you can see that terrible overbite and overjet, and it would take a lot of clearance, vertical clearance in order to be able to move that lower jaw forward. And so a lot of times what happens is we would decompensate or level and align those upper interiors to provide the same overjet that this patient had, right? And obviously we are dealing with obstructive sleep apnea, we can't tell, oh, I say, hey, wait a second, I wanna level and align my teeth first so that I can use my appliance, right? In these cases, we have to use our best clinical judgment. It's best to explain to the patient why the appliance is not ideal at that point in time. And maybe this is when we have to convince them to use the CPAP temporarily while we are preparing their teeth for the oral appliance. And then finally, this is a class three patient, as you all know, it was very, very interesting. I saw this patient recently and she came to the clinic, she was a referral from a physician, and she said, I want to have, or I want to be treated in this clinic, I do not like my CPAP, I want to have, in my understanding, what she wanted was an oral appliance. And then she smiled, right? And I almost fell back because I was thinking, no way. And then I realized she did her reading, she did her research, and what she actually wanted was jaw surgery. So again, I'm including this because that is still within part of the options that we have, right? And as dentists, we need to know when is the time to utilize one option over the other. Currently, she is being treated in the orthodontic clinic to decompensate and to prepare her jaws for surgery. And we managed to convince her to utilize the CPAP prior to the surgical procedure. And so, yeah, very, very important. Note the malocclusion classification of the patient. For the most part, they come like this, right? So just the other day, I had a resident come and say, I was just diagnosed, and she just underwent orthodontic treatment. Therefore, she does not want her bite to change, right? She spent two years in braces, another year in clear aligners. She does not want this compromise. She wants to protect this occlusion. Knowing what we know, now what do you do? So there cannot be no side effect, but the best shield we have, and actually this one should have been prior to that side effect side, but the American Academy of Dental Sleep Medicine actually had a consensus conference in 2017 led by Dr. Sheets, and they published this very good guide that I suggest all of you download immediately. You're all members of AADSM, I'm sure. It spells out what to do in every single instance and every single side effect, okay? What I'm focusing on as an orthodontist, you know, are those dental changes like decreased overjet, decreased overbite, but this manuscript has everything from jaw joint discomfort to gum irritation, et cetera. So I'm really encouraging all of you to take advantage of this article. And part of that too, again, I want to inform you is the importance of informed consent. And informed consent is not just a piece of paper that our patients will sign. It's a discussion, right? Of everything that I discussed with you previously that needs to be a part of your discussion so that the patient understands that these are things to be expected when they undergo oral appliance therapy. But what I wanted to get at for that class one patient, okay, that I just showed you earlier, for my resident, okay, that just came to me last week, who was diagnosed recently, but who has a perfect occlusion, this is the best tool that we have at our disposal right now is a morning occlusal guide, okay? And, you know, we're familiar with this one. We've made it hundreds, thousands of times in our offices, but in some instances, when we're trying to protect the teeth a little bit more, if we have a reason to make it more rigid or more robust, your lab can actually make a mild morning occlusal guide. And it'll look, it will remind you like a surgical splint or here, it reminds me of the daemon splint back in the day. But this one is an example that one of my lab friends sent me, so it's essentially worn on the lower and it has an imprint of the upper teeth, okay? So what, it's just a more rigid, more fitted version of the morning occlusal guide that we're used to. But we need to reinforce the importance of wearing this in order to minimize those side effects that we are expecting to happen. All right, so now I'm gonna go, I am going to go over a few of the frequently asked questions that I get as an orthodontist doing dental sleep medicine. So sometimes I get the question, what about if my patient is a Bruxer, right? I had that, I had this happen to me not too long ago, okay? So yeah, we all learn from our mistakes, right? So it's not good to use those winged appliances when you have a patient who Bruxes, right? It's better to use something with the anterior adjustment or a telescoping rod type of appliance that will allow a figure eight motion of the mandible, right, versus something where there can be no lateral excursions per minute, right? Interestingly, what they did here in order to repair this was they incorporated a mesh on the wings, if you will, before they repaired it. So there are, you know, your lab technicians are also very knowledgeable in troubleshooting, but definitely something to consider in design would be presence of any parafunctional habit. Okay, so another one, so I'm wrapping up now. Another one that I always get asked is, what about if my patient wants to have their teeth aligned? Okay, so my last example a while ago was my student who had a perfect set of teeth, but what if it was another person with some minor tooth movement that's needed? Can I combine some clear aligner therapy with a nighttime appliance? And a few years ago, when I looked this up, I couldn't find an answer, but right now I think every lab that you use will probably be able to make you something like this. So what they did was, or what they would do is essentially have an overlay appliance fitted on top of your aligner, but relieving the area where there is movement to be expected, right? And they have ball clasps, typically, you know, see both of these designs of ball clasps that you can adjust to aid in retention. Let's see, another thing that I learned was sometimes these appliances can be utilized with a thermal liner so that every number of trace, X number of trace, you can realign that thermal liner, and then refit it on the patient. This gets tricky because you don't want it to stick on the aligners, and so you have to use a barrier in order to do it that way. But other than that, this is a doable, you know, option. This is a doable, you know, option. So it has the wings to allow for protrusion of the mandible, and there's screws here to adjust or titrate the appliance, and still allow for movement of the anterior teeth in cases of relapse. That is my last slide, so I am one minute late. Thank you. Thank you, Dr. Kallang. Thank you very much. Thank you, Dr. Callan. Thank you. We appreciate your time. If any audience member now has a question for our speaker and they're using a full screen mode, you will need to exit full screen to access the Ask button to submit a question. I'll be asking the questions from the top down, so please make sure to use the upvote feature to move your favorite questions up the list. Also, in some instances, your questions may be answered by a moderator in writing, in which case you will see a notice under your question with the phrase tap to see moderator answer. And now we have our first question. What is the relationship between four bicuspid extractions and prevalence of OSA? Also, if my patient has four bicuspids extracted, a scalloped tongue and intraproximal spaces opened up significantly. Can we assume that the tongue was making room for itself? Very interesting question. So regarding extractions and OSA. So what I always say is that the airway is a collapsible structure. Right. So sometimes I working in the medical district here in Chicago, I work with a lot of sleep physicians. And in fact, I'm like a very active in the Illinois Sleep Society where I'm one of the few dentists there. And what the physicians always tell us is you guys think it's all about anatomy. Right. And they're talking about us dentists. Right. Like dentists always think it's all about anatomy. And they are reminding us that it's not just it's not just the shape of the arch. It's not just, you know, the the the space for the tongue or where the tongue sits. It's not just the tongue. Right. There are other structures at play with obstructive sleep apnea. And so in terms of four bicuspid extractions, the study that I always quote would be the one by Larson and colleagues where they had a large sample study. And they compared patients who were who were all diagnosed with obstructive sleep apnea, but a set of patients who had four bicuspid extraction and a set of patients who didn't. And they found no difference in the prevalence of OSA in terms of the two groups. As far as the scalloping, the scalloping of the tongue. So there is there are people with lateral tongue thrust. There are people with anterior tongue thrust. It's more of the position of the tongue. I'm not quite sure the tongue. If you are talking about anterior spacing, then yes. The tongue, as one of my mentors before told me, is made of millions of muscles. And no matter where where you put it, if you put it against any set of teeth, the tongue always wins. Right. So you can see it that way if you are saying, is it making room for itself? Then perhaps, yes, you can take a look at it that way. But in terms of it being a reason or the bicuspid extraction being a reason for having sleep disordered breathing, I would politely disagree that that is the root cause. Thank you. Next question. Can orthodontics be used to reposition the mandible posteriorly to reestablish normal condyle-fossil relationship and reverse a POV if the mandible has moved anteriorly with use of MAD? Good question. So in terms of that, in terms of utilizing orthodontics to reposition the mandible backwards, I would probably be careful doing that because if the reason for that would be the MAD use, then you may be at risk of undoing the effects of your OSA therapy. Right. So in terms of in cases like this, I always think about all the people who asked me the headgear question. So I would probably disagree with pushing the joint backwards with just biting force or changing occlusion. In cases like that, there might be surgery involved or an oral surgeon might be involved in reseating the condyle. The orthodontist mainly in this adult stage will mainly be able to move the teeth into the right spot. But as far as the jaw joint is concerned, I don't think orthodontic forces alone would be able to push that condyle. Thank you. What is the value of the information we can gather on a CBCT scan when it comes to predicting OSA? Should we be only looking at the oropharyngeal space or should we look at arch width as well? That's a great question. So CBCTs have definitely been much more common now than it was years ago. And it's definitely a different way of looking at the airway. So we were, if you notice, like a lot of the studies I quoted, a lot of the studies that have been done are utilizing just lateral cephalometric radiographs. The trouble and the good thing about CBCTs is that they're three dimensional, which is what airway is. The word of caution that I want to give you in interpreting or utilizing CBCTs is that up to now, there's still no standardization on the method of taking the image. So as you all know, the airway or breathing is a dynamic process. Therefore, when we capture a 3D image, the stage in breathing is important as well as the position of the tongue, even the position of the patient. So if we're using this as a predictor, let's say of disease severity or predictor of oral appliance effects, we have to keep in mind that we typically use the oral appliance when the patient is supplying in a sleep versus a CBCT where it's upright, awake. So there are differences. So I think we can use it as a tool to help us, but not as a sole predictor. We are not yet there. There are studies that have shown that like the AP versus the transverse dimension of the airway can be utilized as a predictor. But again, we need to pay attention to how are the images taken? Were they all standardized? Was it the same position in time? Was the patient inhaling, exhaling? Was the tongue at the roof of the mouth? What were the instructions when the image was captured? Excellent. Thank you. Next question. What pitfalls should one be on the lookout for the patients who have C2D2 occlusion? Am I reading this correctly? Especially those with retrocline mandibular incisors. So for class two division two, I almost was going to ask you what C2D2 was. I'm sorry. I realized I think what they're talking about is class two division two. So for class two division two, so yeah, the classic, one of the patients that I showed earlier had that occlusion where the upper incisors are typically declined, lower incisors are very deep overbite. A lot of times incisors are impinging. The problem with that is it will take a whole lot of vertical dimension opening in order to achieve that advancement that you will need. And so this is why they would not be ideal candidate for immediate, you know, oral appliance therapy. What I would suggest would be to decompensate those incisors. It will not take too long, but again, like I said earlier, the disease will not wait for us to try and align the teeth. And so I think that will entail a lot of talking to the patient, educating the patient about the importance of possibly going a different route, even temporarily while you are prepping the teeth for oral appliance movement. Thank you. Are younger adults with using oral appliance therapy more likely to have their jaw stay forward? So as you all know, orthodontists typically use functional appliances when they correct malocclusion, but with OSA and younger population, so what I talked about earlier and all the studies we quoted earlier were all for adults, right? Because typically, mandibular advancement devices are utilized in adults who have obstructive sleep apnea in the mild to moderate range. When we're talking about children, the typical culprit that causes their sleep disordered breathing are the soft tissues, the tonsils and the adenoids. So the first line would be a consult with the ENT to make sure that those tissues are not inflamed or enlarged. And it's not typical that those are utilized at that early age for sleep disordered breathing. We usually use them for growth modification when we're trying to correct the malocclusion. So in the process, we may actually be addressing the issue as a bonus, as a windfall effect, if you will. But typically, that is not the first line of treatment for sleep disordered breathing in the younger population. Thank you. Next question. When someone has had adult ortho, even if more than 10 years ago, are they more likely to experience tooth movement than someone with no ortho background? Or is something like lack of maxillary to mandibular interdigitation a better predictor of tooth movement? That's a great, great question. So there was, I wish I could quote all of the studies or include all of the studies that I've read so far in prepping for this talk. There are studies that have found that the patients with a decreased overbite already, which I think is what you mentioned, are more prone to have more of that side effect of decreased overbite and overjet. Now, as far as a patient who has undergone orthodontic treatment 10 years ago, but by now, like let's say they had it 10 years ago, I think the odds are the same with a patient who hasn't undergone treatment. Because by 10 years after, their bite would have been much more stable than if, let's say, the orthodontic treatment was just completed like within the year or within a few months, then the teeth will have much more tendency for you. I see. Thank you. How was the TMJ exam done? Was a CT scan or panel used or was it based on subjective criteria? So that was the, I think that was the one by Dr. Lobizu. It was the Amsterdam paper. I believe they did a clinical exam. I do not think they did any imaging, but I can get back to you on that one. I'm not so sure how you guys can provide me the contact info. I would be glad to get back to the person who asked the question. I have the study here, but yeah, it'll take me time to look through it. But I believe they, if by subjective, you mean was it just palpation, then I believe so. Yeah. Thank you. Is it possible that the maxilla can be moved backwards from the pressure of oral appliance? Yes. So there is. So actually, you know what? I have, I need to, I probably should have included that. Maybe I take that back. The studies that are there that are present, they have overlaid tooth structure. So I know for a fact that there is distalization of the posterior teeth that happens. As far as the entire maxilla being retruded, I am not too familiar with that data, but I know that data exists for CPAP, for CPAP wear. Okay. So if you, if you think about, you know, the strap, the mask, right. So there is, they've shown that, you know, in patients who have Down syndrome, for example, who are prone to obstructive CPAP and they have to use a CPAP at such an early age, there is that inhibition of maxillary development. Yeah. Thank you. We have just a few questions left. For the class three patient, will it be to bring the maxillary jaw forward? Oh, good question. That, that patient a while ago that I showed you, it would have been to bring, or it, she is being prepped currently to bring the maxillary, the maxillary jaw forward. Correct. And then they actually, so the surgeons, if you read their papers, it's usually they want at least a 10 millimeter advancement for them to see any, significant change or impact on AHI. So in her case, we couldn't really bring the lower jaw too far forward anymore to get that six, to get that 10 millimeters. On the upper, they're able to get 10. For the lower, I think they're only able to move halfway for obvious reasons, right? She had that negative overjet to begin with, but they had to taper their surgical treatment plan with the facial profile of the patient. So yes, I mean, you were right. So it's advancement. So it's maxillomandibular advancement, which the literature has shown has a very high success rate as well in treatment of obstructive CPAP. Thank you. What appliance is best to avoid or minimize anterior teeth movement? So I think, like we discussed, most of these appliances do unfortunately still result in that, but what we need to control are the factors we can control, right? I know that 3D, I know I'm not supposed to mention any particular appliances, but there was this 3D printed appliance that is not being manufactured right now. It was made by the makers of the CPAP. I'm sure you all know what I'm talking about. But their appliance was so thin and it did not even cover any of the teeth, right? There was no occlusal coverage. It was very thin, like 3D printed appliance that just had a plate laying against the lower teeth. And it had these straps that you would interchange for titration. And all of the dentists that utilized it for sure saw a ton of side effects. And I think that's probably partly why they don't manufacture it anymore. For a while it was in vogue and they would order it. It was 3D printed from Europe and they would ship it back here and everyone was using it up until the time when they saw that all these dental changes were occurring because nothing was holding the teeth in place, right? It was all those forces being transferred without holding the teeth in place. So what I want is full coverage on the teeth and that way I'm able to hold them in place so it serves as kind of my retainer. And I just harp really, really constantly on the use of the morning occlusal guide. Excellent. Thank you. And the last question, what can be done for the patient who must wear an MAD with mild apnea but has significant tooth movement? So for those cases, if you look at the AA DSM paper with Dr. Sheets, you can have a period of watchful waiting in order to see if the teeth relapse or if that movement stabilizes. Primarily it will be the use of the occlusal guide. I find that a lot of times in those patients who have had a lot of tooth movement or bite change, it's mostly those that are non-compliant with the morning occlusal guide. So I would, if it's significant movement, I would take a break, maybe revisit the CPAP or a different method while the relapse is corrected orthodontically and then start from a clean slate. That's probably how I would address that. Excellent. Thank you very much.

dental sleep medicine

oral appliance therapy

sleep disorders

side effects

tooth movement

patient selection

orthodontics

extractions

CBCT scans