2021 UPDATE: If you want to learn more about Splints, check out the SPLINTEMBER Series I recently did:
The use of anterior mid-point stop appliances (AMPSAs) in Dentistry is surrounded with controversies and misconceptions, so I am joined by Dr Barry Glassman in this episode to answer this much debated question.
In this Episode with Dr Barry Glassman we discuss:
- To what extent are occlusions designed for Function?
- How much does Occlusion matter?
- Why canine guidance?
- Do Anterior midpoint stop appliances cause posterior teeth to over-erupt?
- When to avoid using AMPSAs?
- What mechanism is behind patients developing AOB after splint therapy?
TLDL (Too Long Didn’t Listen): Jump to 22 mins and 30 seconds if you want the main question answered.
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Click below for full episode transcript:Opening Snippet: Most of us, unfortunately go to lectures to have what we already know. Justified. So as long as long as someone is telling me what I know and is what I'm doing is right has been right, then I can take on a new parole or something and add to it. I'm comfortable with that. If someone's telling me that what I've been doing may not be right, that's upsetting. And what I've been saying, Jaz, for years is that I'm not saying that what you've been doing is right...
Jaz’s Introduction: Do anterior midpoints stop appliances cause anterior open bites? Right, so if you’re unfamiliar with these appliances, it’s basically a night guard that only covers that say, 2-2 or 3-3 or 5-5. And there’s many combinations and you know, opposing and whatnot, a larger, smaller, but essentially they don’t cover all the teeth. They are segmental appliances. And the classic version of it, for example would be like an NTI or in the UK is known as a SCi, sleep clench inhibitor. Other versions are available bite soft, FOS which is something I use quite a bit or B splints, there’s loads of different types. So if you’re listening to this podcasts, and you’ve sort of clicked on to find out if these sorts of appliances, cause anterior open bite probably you’ve come across or seen photos, or perhaps you use these cautiously, or perhaps you use this freely, let’s find out. Basically, if the back teeth don’t touch the muscles switch off. That’s essentially how it works. So you’re biting together on the night guard, you’re biting only at the front, the back teeth don’t touch the muscles cannot contract efficiently with the power that they can do when back teeth contact. Why did I do this episode? It’s a huge discussion point full of controversy. Basically people are convinced that these sorts of appliances, imagine one example covering 2-2 will cause an anterior open bite by the posterior teeth over erupting. So I invited an expert in this field in oral facial pain, Dr. Barry Glassman to speak on this topic to give clarity on where these appliance do actually cause such issues. Today’s Protrusive Dental pearl, BRB technique, okay, this is for class four composites or any sort of build up in composite. It’s not the ‘Be Right Back technique because a brb might be, it’s actually called, but Bertholdo/Ricci/ Barrotte (BRB) technique, and it’s shortened to BRB, if you have someone who has had a class four fracture, let’s say and you need to do a nice build up and you want to do a layered approach. Usually, classically, you’d have to do some sort of a wax up and then may take a putty stent on both wax up and then transfer it on, therefore you’ve got your palatal thickness, and therefore you can build the anatomy into the putty index now. So with the brb technique, you’re basically negating the need for wax up, you take a puttyy index to include the fracture tooth, you’re just taking the putty index of the situation you have in front of you, including the adjacent teeth so that you know later you get a positive seat of the stent. And then what you do is with a pencil you draw on the putty where you would like the incisal edge to be, you basically use the adjacent teeth as a guide. And then using a round ended tungsten carbide bur, you remove the silicon putty where you’ve demarcated with a pencil. So essentially, you’re creating the wax up with the bur into the putty. And there we are, you have your instant wax up within the putty to actually build the class four fracture to the correct shape and morphology using a layered approach. So it’s a neat little trick, and I’m going to share that on the blog www.jaz.dental. And you’ll be under this episode in the show notes which you can download as a PDF. So let’s listen to the interview with Dr. Barry Glassman. And for the record of the time of production, I have no financial interest with s4s or Dr. Glassman seminars, some of the terminology and ideas that Dr. Glassman shares can be quite difficult to grasp over audio at the first listen anyway. And quite high, I thought was quite high level expert knowledge he shares with us and some of it went beyond me as well. But I’m hoping that this will settle the debate about anterior midpoints stop appliances and whether they cause anterior open bite.
Main Interview: [Jaz] Thanks so much for agreeing for this honesty it was like I don’t know if you’re into sports and football but it felt like in the last minute of the transfer window in football when you manage to to sign a new player and everyone’s really excited. So that’s how it felt like to me.[Dr. Glassman]
Well, that’s crazy, but that’s great. No, problem. [Jaz]
I don’t want to say off the bat. Your lecture that I went to last year at the BDA in London was actually life changing for me in the sense that you know I’m really into occlusion Okay? So that’s why the whole year this podcast called the Protrusive Dental podcast is not just about occlusion, it’s about all sorts of things in dentistry, but it sort of has a flavor I’m into it. But then your perspective on it, I thought was so, so powerful. And I’m so glad that, you know, hopefully, we can share that with our listeners today. [Dr. Glassman]
Surely. So let’s start with that. How did it change your perspective? [Jaz]
Really, you rewired my brain. And I know you know exactly what I mean, because we just don’t get taught to think about it the way you explained it. So basically, the what I took out from it was when we design you know “occlusal harmony”, when we have everything in canine guidance, when we have everything and in class one, that only, it only really happens when the teeth are together. And that’s obviously the gist of what you’re saying. But when we design occlusions, we design them. And please tell me if I misinterpreted what you said, We design these occlusions for parafunction, we don’t design them for function, but we design them with parafunction in mind. And actually, the only time it matters is when the teeth are together. And maybe the crux of the problem is parafunction is the fact that the teeth are together for too long. What do you think about that? [Dr. Glassman]
I feel like there’s absolutely that is if I were hoping that someone would walk out of the lecture with something that there are two things you’ve said that make me feel as though you that I was successful in that lecture. The two things were Yes, that we design occlusions for parafunction not for function, that when we look at the amount of time that teeth are actually together, and whether they’re actually together when we function, and when we think about it, we don’t really, we don’t ask patients at the end of restorative visit that the next time were they able to eat meat the next visit. Very rarely a complaint that patients have, I can’t eat as well as I did. The show that so it’s really, when we look and see where are those teeth contact during function. What we know is that it’s unpredictable it has nothing to do with what we could evaluate on an articulator. And as you know, you can’t look at a case and say, Well, this is where it’s going to hit when we’re functioning, we have no idea, if it’s going to hit our or where it will hit or what inclines and etc. And it has a lot to do with our, you know, the masticatory cycle and the bolus and the kinds of things that you know, this amazing body that God or Darwin has put together has created and it’s overwhelming the amount of proprioceptive and mechanical receptors, information that goes into the buttons of our nucleus and into our central nervous system. [Jaz]
I recently learned to appreciate that what you’re saying there is I read a book a handbook by someone called Jay Levy, I think I believe is based in the states and his sort of research was, just how much sensory feedback is contained in teeth, sensational amounts [Dr. Glassman]
I mean, the spirit of the whole mandibular function it just it we can’t even pretend that we can no and this doesn’t make us any different than medicine. It’s not like medicine knows. When we look at a car accident we look at where someone gets injured and we’ll try to we try to figure out the force vectors.We can we know that you know, there’s there’s no relationship between the amount of force and the amount and of cracks and the amount of damage done to an individual. It all has to do with magnitude and direction of force vectors that are too difficult for us to analyze. [Jaz]
Absolutely. But before we delve in any any more Dr. Glassman, I just want to say for because some people may be listening and they don’t know who you are. And I feel like we got so into it because I was I was sharing my excitement of having you on. So again, thank you so much for joining us. I noticed that your you know your diplomat of so many things diplomat of the board of the American Academy of Craniofacial pain, the Headache Society, Orofacial pain, I’m just picking a few of what you are. Tell me [Dr. Glassman]
Jaz, I don’t really know that all that you know, to be honest with you, I appreciate that. I don’t know that there isn’t any of those that make me feel you know that make me qualified enough to speak on the subject as much as my intense interest in science that I find this fascinating is rivaled by so many others like yourself. So it’s Yeah, I appreciate all that. And I know that that looks. You know, people look at those things. But you and I both know that that’s there are lots of that. If I look at some of the restorative gurus and I look at some of the things that they you know what they’ve accomplished. You would think that there end therefore will carry weight. And I listened to what they say. And I shudder. [Jaz]
Well, listen, you’re very humble. For anyone who wants to read it. There’s a list of, you know, your credentials if you like. But, look, I can say that when I went out lecture last year, it really resonated with me. And then I read a chapter of yours in a book by Steve Hudson, that you did. I’m trying to remember that is, I think, is it messages from dental masters? I think it was that one. Anyway. And it was you were discussing about the whole teeth occluding together and whatnot in which we’re going to come on to this in the podcast, but definitely, you’ve had a massive impact on my career, my treatment planning, my thought process. So thank you so much for that. And I want to be able to share that with everyone. So yes. How did you get into being interested in this field in particular, ie, I guess the wide term would be a occlusion, but you might want to call it something else orofacial? What do you want to, How do you want to describe that? [Dr. Glassman]
Pain management, joint dysfunction? [Jaz]
So how did you get into that? [Dr. Glassman]
Yeah, it’s the way that I think many of us get into it, I took what one of the reasons I teach Jaz is that I tried to avoid for everyone else in our profession, the treacherous path that I wound up taking, I got into in the late 70s, before many of you were born, I was cheating a young woman in her mid 30s, that I truly believed and trusted, who had specific maxillary bicuspid pain. And no matter what anyone ended on this, they eventually had the tooth extracted, eventually had the bridge placed and nothing could resolve her pain and someone came. And at that point, a flyer came across my desk to be to go take a course with Niles Guichet, who was teaching the what was called this occlusa studies, society for occlusal studies. And his basic concept was that everybody should have their condyle up and back in a reproducible position. [Jaz]
Where I ever heard that one before? [Dr. Glassman]
Yeah, exactly. [Jaz]
Then happen? [Dr. Glassman]
And well, I don’t want to go through the whole I, the reality, is that I went from camp to camp I studied with Harold Gal for seven years, I studied with neuromuscular with bio research for years. And I was just, you know, looking for more answers. That, and believing everything I was told, when, in fact, all this much of that information. And as much as I have respect for many of these, what I call pioneers, people who, created a path for the science that we now have, just like those pioneers were fabulous, we certainly wouldn’t want to be using the maps created by the original pioneers in the United States. And unfortunately, those pioneers were very happy to see growth and change in their map. Unfortunately, our gurus don’t want to see growth and change because it seems, to they seem to be very protective of their legacies. And so when science comes around and demonstrates that maybe some of the things that they were teaching wasn’t accurate. For example, interference is causing hyperactivity and lateral pterygoid spasms, which we now know doesn’t happen, [Jaz]
All the myths that are out there, as someone who you know, I, religiously, but I go to a lot of occlusion courses, it’s my thing I really enjoy, I really do enjoy, you know, the whole temporomandibular disorders, doing more complex rehabilitation and stuff. So I you when you’re designing an occlusion from scratch, when you’re trying to protect your restorative work, I suppose, then you do, I do follow those principles of you know anterior guidance and that sort of stuff, the sort of thing, which only really matters when your teeth are together. But I think when you’re doing a rehabilitation, you sort of have to begin from somewhere. [Dr. Glassman]
If you have a choice between having more forces during parafunction, or less choices, why would you take more? So the answer is, of course, that’s exactly right. There’s nothing [Jaz]
and I feel some people are misunderstood you Dr Glassman I don’t know if you know, but I feel as though some people think that what you have to teach is saying that you can do anything you want and you don’t have to follow strict protocols, or do you know the way that we’re supposed to a full mouth rehab? I think they’ve misunderstood what you’re trying to do and what your messages and that’s what I’m hoping to send out today. [Dr. Glassman]
Well, I get that in all the words I get a lot of interpretation. I will I’ll say occlusion doesn’t matter unless you’re occluding, and people only hear the first part. And so they only hear that occlusion doesn’t matter. And the problem, Jaz, with that is is that it and the reason they hear that is because everyone’s telling them how important that occlusion is the key. It’s the answer. And if and so as soon as I say occlusion doesn’t matter. It just turns people off. I’ve learned it You know, it’s funny, I will not accept an invitation to speak at a study group for an hour on occlusion. Because I know at the end of the hour, I don’t have enough time to do what you said in the very beginning, the first thing you said to me was you were rewired to think differently. Well think about that, Jaz. In order to be rewired, you have to get rid of the existing wiring. And then you have to rewire. [Jaz]
Yes, you have to open yourself up. And I’m sure people come to lectures and didn’t have an open enough mind. And they were just very set in their ways. I’m sure we have stories, people, maybe I don’t know, Has anyone ever walked out? [Dr. Glassman]
Oh thrown stuff at me, you know, and I and no question I get, there are people that had to do when, many of us go to lectures, for many reasons, no one in in the UK, I’m gonna say going to the UK, it’s not as much fun because everyone’s so polite, but I have always very respectful. And I have no idea how angry some people are. Because I, you know, because of the tendency to be respectful. In the United States, they’re not quite as respectable, so that we’ll go ahead. And I mean, you know, we’ve got Trump as president for God’s sake. So, they’ll go ahead and throw it off and interesting to me, you know, whatever. But so what I’m saying is that people go to lectures for various reasons. And the most of us, unfortunately, go to lectures to have what we already know, justified. So as long as someone is telling me, what I know, and is what I’m doing is right has been right, then I can take on a new pearl or something and add to it, I’m comfortable with that. If someone’s telling me that what I’ve been doing may not be right, that’s upsetting. And what I’ve been saying, Jaz, for years is that I’m not saying that what you’ve been doing is a right. If you’ve been receiving success, and doing whatever you’re doing no one who would, whom I say it isn’t right. What I am suggesting, is that maybe it was right for other reasons that you suspected, maybe it’s right, because the mechanisms that are at play, the contributing factors that we’re touching, are different than you suspect that they are. And if we are truly understood better, both the contributing factors that we were controlling, as well as the differences that exist from patient to patient, then we could put our treatment into better perspective and help more people more conservatively. [Jaz]
Brilliant. Well, I think people are listening to this now and I feel some people may be saying well hang on what is the crux of where are we going to. So the main reason I want to get you on is because I you know you’re someone who based on that lecture I went to, I can speak to you for days and days and days you know I’m really really love the devotion you put into this to come up with something so simple. But obviously your lecture, you’re coming to London and Sheffield soon you’re lecturing about it. And I can give people the details, but I wanted to just homed in on one specific thing and that was anterior midpoint stop appliances. I see on you know, I’m sure you get your I know you get tagged on Facebook and stuff all the time and people getting into that debate and use it I’m sure you’re sick of it, seeing it all the time. Okay? Basically, when I was at dental school, though, that these appliances are the devil’s work, because they will cause over eruption of the posterior teeth. And you will get an anterior open bite and all sorts of terrible things will happen to you. So can you please tell me or tell the audience I know already from going in lecture, but why this may not be the case or it may be the case but and perhaps in a different mechanism? [Dr. Glassman]
Okay, so let’s talk about first of all, why we use anterior midpoint stop appliances? So the or what the purpose of any appliances? So I would ask you as a dentist, you’ve got a patient and you’ve got let’s say something very specific. We’ve got a patient with some joint pain upon wakening and a suspicion of an early internal derangement of some sort, whether it be an inflammatory state, whether it be this slightly compromised, tethering of the disk and some clicking. So we’ve got some low level clicking and significant joint pain upon awakening. Okay? So that’s what we’ve got a patient that that dentistry will say has some TMJ or TMD, which, as you know, drives me crazy. But nevertheless, but we can’t get into everything. So I say to a dentist, general dentists, what are you going to do? He says, or you know, I’ve got a patient that and you know that they brux their teeth, you can look you can see wear patterns etc. So what are you going to make? He says, Well, I’m gonna make a night guard, great. I said, so and you tell me as a dentist, as someone before you took my course and someone said, I want to make a night guard. And I would say to you, what’s the mechanism? How is that night guard going to help? [Jaz]
So before I’ve done your course, I would have said, I’ll make a bite raising appliance or wherever it is. So maybe a soft bite night or maybe a Michigan splint, if I was feeling fancy if the patient afford it, and the mechanism that would work would be raise the bite, therefore, it will take the condyle slightly away from the fossa and allow, you know, the inflammatory exudates, to be cleared and reset the system. So they will stop bruxing. That’s what I probably would have said beforehand to which I, you know, [Dr. Glassman]
Well, no, that’s a great answer. That’s a great answer. Because that’s, you know, and everything in that answer is wrong. So there is some, in fact, to be honest with you guys, that’s a better answer, then I usually get when I asked Dennis. So obviously, your interest is greater than many and many who may be listening may not have come up with all that, or maybe some of you would have that’s great. The reality is that yes, we know that there is no true what we were taught in dental school, remember that we’re taught about the first 20 millimeters is pure rotation. And we know that isn’t true. So we know that there’s a meeting. [Jaz]
That’s correct. Well, that’s why I understand not only from your course, and I went on I read further and I delve further into it. So yes, I now accept that it’s not purely rotation. Yes, it isn’t an articulator but not in the mouth. Right? [Dr. Glassman]
Right. In articulate has nothing to do with actual the way condyle actually function. Yes, so now we, so as soon as we put something between the teeth, now when the elevators contract and bring our teeth up against it, we can’t close as far as we could have. And consequently, our condyle when we’re done, we’ll be further anterior than it would have been if we had not that piece of plastic in our in between our teeth. So yes, we bring that condyle, down and forward. And if there’s an inflammatory state, and there’s there’s a potential, reducing it, what we haven’t done is we haven’t significantly altered. So the force magnitude, the magnitude, what we know is, and we show this in the courses, remember, we actually have a video where we show you that when there is dental contact, we all know this as dentist, we all know that what’s the purpose of lateral excursions, canine rise and lateral excursions it is in both countries would say it shuts off musculature. What does that even? [Jaz]
That’s right, Bob? And I would like to say please correct me because I, you know, please correct me if I’m wrong, but what I’ve been understanding is that on your canines, it goes down to 30% of maximum? [Dr. Glassman]
I don’t know that. That may be it, what we do know is we look at the studies of Victoria and others, the further posterior the contact, the greater the forces in terms of magnitude. So your canine contact is better than bicuspid contact. But I’d rather not have canine contact, canines, what we’ve learned our posterior teeth-functionally, but anterior teeth-aesthetically. So giving a patient canine rise in their natural dentition, as you earlier explained, is the best parafunctional control that we can obtain in a natural dentition. And oftentimes, Jaz, that’s more than adequate to keep our patients within their adaptive capacity, I’d actually have our patients heal if they didn’t have that level of protection prior to us giving it to them. So, whether we give it to him with an appliance on Michigan, whether we give it to him within our calibration, we have the potential to help patients in that regard, no question about it. So when people say, I say that you can’t help people with you know that you need to have anterior midpoint stop appliance, they never said that. That’s not what I’m saying. What I am saying is that in even superior way to reduce those forces, if we look at the study of May in 2000, where they looked at EMGs, and they looked at specifically at condylar compression, we find that in anterior midpoint stop despite what we’re taught that it’s going to increase the force because of the lack of posterior support, we find out that that’s not true, that it actually decreases the compression and that when you combine the magnitude and direction of the, because of the direction of the masseters, anteriorly and the anterior temporalis was as in the anterior component, there’s nothing driving that condyle back the way we were taught into retrodiscal tissues. [Jaz]
It’s like a nutcracker, but your furthest away from the hinge part of the Nutcracker. Right? [Dr. Glassman]
So you’re describing, interestingly enough, what you just described is the alteration in the force, in the magnitude of the force. So yeah, so as the more anterior we come the further we get away from a class one lever, the forces decrease. But more importantly, also were as importantly, is that not only those forces decreased, but they don’t incorporate what we’re taught that those forces will incorporate with an anterior midpoints. They don’t incorporate a posterization of the condyle, leading to pressure against the retrodiscal tissue, and pain. If so that the purpose then of the anterior midpoint stop is to create the best environment, or altering the force direction and decreasing the force magnitude during a parafunctional event that has no known cause [Jaz]
Perfect. So then why don’t they cause an anterior open bite, that’s the next thing you’ll find that, you know, written around people. The main reason why people don’t use it. I was scared for the first three years when I was qualified of using these appliances, even though I taught, been reading about it, but I was scared to use it because I think I’m gonna get sued, it’s gonna happen. This is not the right way. So I was scared because of that, the myth that it’s gonna cause an anterior open bite because your posteriors will start over erupting. So, can you please bust this myth? [Dr. Glassman]
Yes, they don’t overerupt. [Jaz]
there we are, it’s finished. [Dr. Glassman]
So, what, it is facile. So your concern is appropriate, and you should be concerned. So, let’s make a couple of statements. Number one, posterior teeth don’t over erupt. Over erupt cause there’s an anterior midpoint stop appliance in place any more than they will over up without an anterior midpoint stop in place. So when Avaya said you jazz, are you wearing an appliance at night? Say No. No. Good. Good answer. What made you say that? Okay, so are you wearing appliance tonight? No. So then if you’re not wearing an appliance at night, what keeps your teeth from over erupting? And someone would say well, the dental contact that’s what are you talking about? There is no dental contact is as you go deeper into sleep, there’s more and more muscular relaxation, your use you swallow tooth 3000 times a day, but you only swallow two to nine times an hour, you swallow with less veracity, the EMG levels are less and the likelihood of reaching MIP during those walls is next to zero [Jaz]
In a non parafunctional person, right? [Dr. Glassman]
Next to zero in the swallow. Okay. That Yes, in the swallow. So, what is it that keeping your teeth from erupting? What is that? How is it very different than if I put an anterior midpoint stop appliance in? So why? Why aren’t we getting supraeruption normally, so the reality is this, but you and I have dentist and we have seen when we lose an opposing tooth, we get super eruption. And and when we look at the studies of Robert and the studies of others, what we see is that after 16 hours, there are true bicular changes that lead to the super eruptive activity. So consequently, as long as these teeth are in function, the likelihood of supraeruption becomes next to zero. So I have patients for example, Jaz that wear their nighttime appliances. They were a daytime appliance, which we call a maxillary anterior passive appliance that they wear at during the day to stop their bruxism, especially dentists, just sayin. So they wear their daytime appliance, they wear their nighttime appliance. And as long as they remove these appliances to eat, the likelihood of developing an anterior bite goes extremely low. Now, when interestingly enough, when these anterior open bites do occur, and they do when they do occur, if you then and we’ve done this over and over, I worked with Keller labs who makes the their work in the United States or NTI is in the UK there are SCis. And I’ve worked with Keller lab that made these NTIs and we did a whole bunch of studies with patients who developed it to your overbites and I did them with my own patients. And what we found is that if we took them two models of those patients and put those models, they fit together perfectly. Clearly this was not then supraeruption, there was something different happening. Now I explained this in the course and I don’t mean I don’t want to make light of this or skip over it because It’s awfully complicated, but what [Jaz]
It is. And I think that the course gave it the Justice and the time it deserves, because this gets discussed about so much. And it’s such a big issue in appliance selection that people are worried about. So it does deserve more time. But I think people appreciate that, you know, we’re trying to keep it concise. Yeah, yeah, [Dr. Glassman]
We talked about what we’re looking at is literally a change in Chi forces, and the change in the trajectory pattern in the neck. So the bottom line is this is that you never want the punishment to be worse than the crime. So we would never suggest that you use an anterior midpoint stop appliance in an asymptomatic patient with specially if the overbite is a as less than a millimeter, because that’s the patient that could open up on you and and you go, Oh, my God, what happened? And now the patient can bite off letters or something, and which is no big deal. My pain patients, they could care less. But if they didn’t have pain in the beginning, then the punishments worse than the crime and they’re not happy and they shouldn’t be at. [Jaz]
That’s a fantastic way to say it. You know, I still remember that saying that. And I say to my patients, you know, what you said, and you know what the other thing I say to my patients what you told me? Okay, and you said these three words already to me? [Dr. Glassman]
I don’t know. [Jaz]
Okay, yes, it is exactly. You said, I don’t know. Cuz I said 30% of the canine thing. And you’re like, I don’t know. And, you know, I think we had a moment at that lecture, where you just, for the first time said, Look, it’s okay not to know, don’t just say, I don’t know, just learn to say it and [Dr. Glassman]
We actually have everyone say it together. Because here’s the reality, I got sick and tired of going to all these gurus that knew everything. And when they didn’t know, Jaz, they made stuff up. They just made it up to connect the dots. Because God forbid, you know, you paid the money, they should know the answers. And the answer is often is I don’t know. So I got over the, you know, a lot of people got really upset with me, because it’s a guy, you know, I paid a lot of money to hear what you don’t know. So I changed it to. It’s not No. [Jaz]
It’s not No, but you know what, it’s still though that was a great thing. So thank you for changing that about my life as well. So right, so we said, What anterior midpoint stop appliance are, we talked about scenario patient. We talked about how through mechanisms, they cannot cause an overeruption, but they can cause AOBs due to condylar repositioning? Is that the best term? [Dr. Glassman]
I know, I would say they it’s possible for the use of an anterior midpoint stop to contribute to an anterior open bite with altered trajectory as a result of usually an improvement in the cervical kyphosis or cervical lordosis. So that’s a little it’s really not condylar position, as much as it is the altered trajectory. [Jaz]
Can you make that a bit more tangible? Because some of those terms i’m not i’m still unfamiliar with. Can you make it idiot proof for someone like me? [Dr. Glassman]
Sure. Take your lower jaw and rest it. Close together. All right. Now, if you just take your lower jaw and rest it now, and move your jaw slightly forward, or just forward just or from that position, don’t moving forward, just change the way you close to alter the trajectory. So now you’re only hitting your anterior teeth. Alright, you starting in the same position, your condyle is in the same position, what your trajectory changed. Now just imagine you can’t do this, just imagine you change your trajectory. So that your, whole mandible closes with a with a back teeth touching are going to hit first. Now because with that change in trajectory, you’ve got an anterior open bite, your teeth are exactly the same. You haven’t changed but the trajectory changes, the musculature and combined with the posture and your and your and your head, neck. Now if you change you know, it’s it. Think about this, you How many times have I seen a dentist spend an hour two hours perfecting an occlusion, just making everything perfect and the patient’s lying down in the supine position and they’re gone tap, tap, tap, tap, tap, tap, and they’re making I know now they’ve got that perfect all the dots are lined up and it just great, you know, and they think oh, wow, I’ve completed this and what I want to say to them now sit the patient up, I’m closed. What’s gonna happen? [Jaz]
It’s gonna change his posture related as well. [Dr. Glassman]
Of course, so the trajectory changed. If you didn’t change your teeth. You didn’t change the position in your in a condyle of in the fossa. Your trajectory just changed So if were your posture changes in terms of your head and your entire head and neck, this was brought to us when we had Mariano Rocabado, from Chile, spent a week in my office and went over this. And he explained it in detail and showed us and we actually took cervical films of my patients with before and after treatment, and because I had taken them all before, and now these patients with open bite came, they took new ones and all of a sudden, each and every one of them, we saw an improvement in their in from their khyphotic curve toward more normal lordotic curve, and all of them had the anterior open bite. [Jaz]
That’s amazing. And that’s another great thing you’ve taught me because I actually learned about the Rocabado Pain Map. Maybe in February actually. So it’s amazing how that’s coming back. Is that something you use in your practice [Dr. Glassman]
We use Mariano’s exercise program, or attempting to strengthen ligaments? It’s brilliant. And some of Mariano has concepts in terms of joints. He spent a little more time lately with some of our neuromuscular friends. And I think he’s, well, I’ll leave it there. [Jaz]
Okay, thank you. Okay, so it comes to conclusion that through the mechanisms, you described, changing trajectories that AOBs can happen, but the mechanism is not over eruption. [Dr. Glassman]
And keep it as also keep in mind that the anterior open bites have been recorded and happened with forward arch, I mean, they just [Jaz]
Oh, yeah, my principal, though, the worst one my principal ever had it on was a significant one from a Michigan splint. So it can happen from any splint, really. The types of patients I avoid delivering AMPSAs to are people who yet have a minimal overbite, already asymptomatic that, just like you said, and also the other one I like to put in there and tell, you know, tell me what you think about this is people who, when you tell them bite together, they say which bite like they have, like, they don’t have a well defined MIP they quite warm, they sort of don’t have sort of a good interlocking. Is that something that it could be a thing? Because that’s something that I love, you know, try and avoid, because I somehow think that in that patient, you might get more of the sort of slipping up like always changing trajectory, as you describe it. But I would have before this conversation, I would have said condylar repositioning, but obviously I see what you mean. But is that one to be avoided? Is that? [Dr. Glassman]
I don’t know. I did so, I don’t know, that raises a really good, that’s a whole another discussion that we can have in you know, in our course, we spend a little bit of a significant amount of time talking about occlusal dysphasia. And, and the concern for, which means a patient who has become hypersensitive or aware of their bite, and how we create that. And you know, so how do you deal? How do you deal with the patient that comes in and says, Dr. Jaz, I have two bites, can you help me? Or Dr. Jaz, my bite’s not comfortable, can you help me? I’m only I know that we really don’t have time to go into that, Jaz in detail. But I always say the last thing you want to do with either of these patients is even look at their bite, even evaluate their bite and God forbid, change their bite. So and yet you can’t help them. So we go over we teach that because that’s really an important extremely important there’s not a dentist that I know that hasn’t dealt with somebody hasn’t walked in and said you can you help me doc, my bite’s just not comfortable. And how you deal with that. I don’t mean to be you know me, I’m not this is not I don’t believe in mama drama, I hate it. But I will tell you how you deal with that has the potential to save someone’s life. That’s how important this can be. [Jaz]
Brilliant. And I just asked two more questions not because I think we’ve answered the main question about anterior midpoint stop appliances, over eruption which keeps on coming on and on and on. But I want to say is an anterior midpoint stop appliance, Are you concerned about its long term use? [Dr. Glassman]
So that’s a real, that’s really interesting, because we [Jaz]
by long term like years. [Dr. Glassman]
It is true and we hear this all the time. You know, some really good instructors in prosthetics. And it’s very common for them to say, well, you can only use it in a muscle issue, not a joint primary joint issue. And of course, Jaz. Why do they say that? Why would they say you can’t use it in a joint primary joint problem? [Jaz]
Because they think that it will impinge on the retrodiscal tissues eventually, if they think that the condyles will be driven backwards, right? [Dr. Glassman]
So to please do me a favor, and don’t let the guys at s4s Matt Neel, know how much you know Because otherwise they would never pay that straightened me all the way over, they would just hire you. Yeah, absolutely. So there could there they’re there the literally concerned about. So they can’t use it in a primary joint for that reason and as a temporary a plan. So why do they say a temporary appliance? Because otherwise long term, we’re going to develop the supra eruption, and in their way, [Jaz]
and also I’ll add to this, that it’s a temporary appliance, because then you won’t get through the ffull mouth rehabilitation to get it? I mean, I know, I know, that’s really naughty. But I feel as though you know, that is the other side of it. The ugly side of it is that, you know, these splints could be done in patients in pain instead of Oh, I think there’s full mouth rehabilitation, pain, well, actually the splint will has it’s role as well. And maybe, you know, [Dr. Glassman]
So let me address that because I think you just hit something extremely important. And that is, we are talking what I call the restorative pain, disconnect. Now, this is not mean, people, again, so readily misinterpret this and think that I’m saying that there’s no relationship between occlusion and occluding, and pain dysfunction. Of course, there’s a relationship, the all my goal is the keystone of my treatment is not not let those teeth touch at all. So yeah, if I’m trying to keep the teeth apart, then clearly them being together creates a problem, though, our problem in dentistry is that we assume they are always together, we think of teeth, were trained to think of teeth as together. So we want to look at when they are together, and then keep them from getting together and then reducing the forces and allowing God or Darwin to heal. So but what often happens is that there’s this, this connection, I’m going to put in an appliance that’s going to tell me where this jaw has to be. And now I can do 36 crowns. In order to put the jaw were supposed to be now you people often say very, that’s ridiculous. They’re only 32 teeth. And I said, I know. But if they can do 36 crowns, they will. So yeah, there’s so our concept is that we don’t do restorative therapy to help our patients. We help our patients so that we can do the restorative therapy they want or need. [Jaz]
That’s perfect. And I think that’s worth repeating, I will sort of copy and paste that snippet and say it again, because that is the real crux of it. That’s awesome. And I just want one more question now. There are a couple of occlusal camps whereby Some people say that actually, all these studies show that during mastication, and while we consume our foods, our teeth do touch together. And there’s another camp that say that actually, when we’re producing the bolus itself, our teeth do not touch together. And I still don’t know the answer. Do you know the answer? [Dr. Glassman]
So they do together? [Dr. Glassman]
No, you asked me if I knew the answer. [Jaz]
Okay, so can you please shed the light on that? Because, you know, what is the answer? Because I hate this, two viewpoints. I’m pretty sure I can give you two papers where they argue different things. [Dr. Glassman]
Right, exactly. So here’s my question, no matter what the answer is, explain to me how it matters. [Jaz]
Okay, that’s a really good question. Let me think about this. It matters so that next time this debate comes up that I’ll have the right the right answer. Otherwise, [Dr. Glassman]
Let’s go back here. So let’s assume that they do talk. The question is, what does that mean, then, and how do they touch? And how does it matter? So one thing I will tell you, let me ask you this. If they touch will they touch in MIP? [Jaz]
See that I I’m pretty sure myself I mean, from what I read is no, we don’t fully get into MIP, Am I right there? [Dr. Glassman]
MIP!, If you had a P in your in your on your right side, you’re no longer in MIP. [Jaz] Correct. So if there’s any if there’s something between the teeth you can’t reach it might be now you take a normal bolus and you put a normal bolus in between your teeth. No, And not only that, you’re when you look at the masticatory cycle, you look at an elliptical pattern of 19 to 21 millimeters that has that doesn’t even approach you know, this concept of fencing, functional fence. When you think about it, the role the teeth play in our masticatory cycle is next to zero. Whether you’ve got flat cusps, whether you got deep cusps, you’re going to chew like a cow or like a rat. Oh, you kidding. There’s, there’s a must, there’s a functional generator that controls our pattern has nothing to do with our teeth. And then as soon as you add bolus, the angles of those cusps are next to meaningless. So the answer is yes, they can touch in some inclined plane is somewhere along the line, they don’t touch with any force or with any duration to they can’t do that create the damage that is done during parafunction. And so so while it depends upon the patient’s adaptive capacity, if their capacity is so low that any contact, any increase in EMG levels, can set them off in terms of any of the components of the structures, sure it on those patients, we tell them, you know, you got to eat softer foods. But the vast majority of are patients with temporomandibular joint issues, we tell them, you can eat whatever you want,as long as it doesn’t hurt you. If it hurts you that signal to tell you, you shouldn’t be eating it. But what you can’t do is sleep without my appliance, because that you can’t control and those forces are far worse than the forces you’ll be experiencing during function. [Jaz]
Excellent. And what percentage of people display or exhibit paraunction at nine times? You know this one? [Dr. Glassman]
Yes. So if we look at the literature will get anywhere between 8 and 80. So you get so so so the literature is very, very dispersed on this, here’s my question to you, you’ve got the hardest structure in the body on the upper arch. And then on the lower arch. You see wear patterns when these teeth. You tell me what happened? How can we lose the tip of a canine? How is that possible? When we know God, or Darwin put one there. So if one is missing, or we see wear patterns in teeth, there’s a firm suspicion that that patient either is bruxing, or has bruxed, remember, there is no timestamp here. So it doesn’t repair itself. So the patient may have bruxed and may or may have stopped. But we know somewhere along the line, there was there’s a history of parafunction, you can’t use a you don’t have the intensity or the duration to alter two surfaces. Now, in the United States, there’s this whole thing called occlusal disease, this discussion of you know, the United States and blaming all of us dentists were all horrible people because we are not diagnosing occlusal disease. And we’ve got to restore and repair all this occlusal disease. And you know, in our course, we spend a lot of time looking at all the factors of the craniomandibular system, and putting the teeth in perspective. And understanding that, you know, you can get wear patterns on teeth and if you don’t have any other signs or symptoms, and you’re not concerned about the wear patterns, and the patient’s not concerned about the wear patterns. So be it. You know, if we don’t, you know, with that’s not you haven’t done a horrible thing, by discussing it with a patient. And if the patient doesn’t want anything to do with it, you know, isn’t concern, we shouldn’t I don’t know of many people that have died of tooth wear, and, or even aesthetically, major issues. And if you want, and if you want to restore the patient wants to restore them, then we can do that. But darn, we better do all we can to protect what we have restored from the forces that created the problem in the first place. [Jaz]
Brilliant. Dr. Glassman, thank you so much. I think I’ve got lots of awesome content here. And I think that’ll really answer the question about the anterior midpoint stop appliances and over eruption. Is there anything, any final comments? Obviously, I’m gonna include information about your course, which I think everyone should go to, because I think it will really rewire your brain. And it was so powerful for me and my career trajectory. Is there anything that you’d like to add? [Dr. Glassman]
The only thing is that I want to make it clear that because we’re looking at things that are different, doesn’t mean that there’s the fear that what we’ve been doing up to this point has been wrong. It may be that it has been right. But it may be right for reasons different than we once believed. And that we shouldn’t be afraid to ask the questions so that we can get better at solving more problems more conservatively for more people. What I’ve learned is what general dentists are capable of doing is massive that for a long time what I realized is that when I started using these anterior midpoint stop appliances, what I found was that patients would come to me and with a series of symptoms and problems, and we would start them on their appliance therapy and three weeks, four weeks later, they’d come back and we say, Okay, now we’re going to start with all the other supportive therapy that we had mine. And they look at me and they say why? I’m better. And what I realized is that dentists can do that. And then they can refer to people like myself and other oral especially oral facial pain, people who have learned their practice oral facial pain, and then for support of therapy, they can go there for that. So that support therapy, but it’s amazing how much they can accomplish in their own offices, once they get over the fear of failure.
Jaz’s Outro: So thank you very much for listening, everyone. As you can see, I really enjoyed having Dr. Glassman on the show today, was really useful, great knowledge. And so we have the answer. Anterior midpoint stop appliances will not cause anterior open bites because of posterior over eruption per se. However, in a small percentage of cases, with any appliance and including anterior midpoint stop appliances, you can get anterior open bites. And the mechanism is not posterior over eruption, it’s a change in the trajectory of how your teeth come together. And there are certain sort of risk factors that might predispose you to having an anterior open bite, and that’s covered really well, obviously in our conversation with Dr. Glassman. And the thing to remember, I suppose, is as Dr. Glassman says the punishment should not be worse than the crime. So try not to use it in asymptomatic cases or those with minimal overbites. I tend to use them for my pain patients or those I want to deprogram diagnostically. Well, thanks so much for listening. I just want to mention before you go about the Dentinal Tubules Congress in October, if you haven’t already booked, what are you waiting for? It’s something that you know, I look forward to every year and I hope to see you there. It’s got some great workshops including occlusion, complete dentures, preparation where they sort of scan the teeth at the same time you get like instant feedback. So all these workshops still aren’t available at time of recording. So check out Dentinal Tubules Congress in October, and I look forward to seeing you there. I’ll put the link in the bio. Thank you.