I left you on a bit of a cliffhanger last episode – but now you can finish off Andy’s ‘origin story’ of Posterior Guided Occlusion (PGO) and understand how this is practically implemented on patients.
If you missed Part 1 and the ebook by Dr Andy Toy, check it out.
The Protrusive Dental Pearl for this episode is continuing on the theme of Dental Photography I have been posting about on my Instagram. When taking portrait photos for your patients with a ring flash, point the ring flash at the ceiling, rather than at the patient’s face. This creates a softer, nicer image!
If you missed out on my Butterfly Effect webinar, you can now check it out on www.protrusive.co.uk/butterfly – it’s about how seemingly small events in your career can compound and change the entire trajectory of your dental career.
I added a new book to the book list – the Danish Way of Parenting!
In this episode we discuss:
- Structural school of thought vs Functional school of thought
- The relationship between the condylar movement and the teeth
- The mathematical equation that is evidence for PGO
- I ask Andy questions to test PGO
- What does he mean by functional contacts?
- What is the healthy clench?
- We debate anterior guides vs posterior guides
- How does this apply to the patient with large masseter muscles who keeps breaking cusps?
- How many ‘centrums’ are enough?
- What Andy is prescribing in Clinchecks for the posterior occlusion
- How to finish the occlusion on an orthodontic case – and how Andy makes this ‘patient driven’
- How Andy finishes 60% of his Invisalign cases with a ‘Dahl appliance’
- Is Centric relation important to achieve?
- Andy tells us the birth of Canine Guidance
Click below for full episode transcript:Opening Snippet: The occlusion becomes more simple. You have to work less hard because all you got to do is make sure there's good posterior guides. And all that work you do not the front of the mouth. As long as you don't get too much of a clash there, okay? Then life becomes much, much more simple and you can, canine guidance isn't a bad thing. But it's not essential to a healthy functional bite. Okay?...
Jaz’s Introduction: Hey, guys, and welcome to Episode 32. This is posterior guided occlusion part two, with Dr. Andy Toy. I know I left you on a massive, massive cliffhanger last time. And I hope you can join us again, to get the complete story of how to actually apply the PGO concepts. Now something like I told you guys, it was me learning a bit about this concept for the first time like many of you, so it might take me some time to implement this, if I do end up fully going that way. But it’s just great to hear other points of views and other theories out there. So I’m so glad that Andy, Dr Andy Toy was able to share that all with us. Before we join Dr Andy on the show, again, with part two, I’m gonna give you the Protrusive Dental pearl. And this is a photography one, which has been quite big on my Instagram story recently, I sort of gave a hint that I’ve ever invested in some new sort of photography, flashes and lighting. And I’m gonna go into a lot of detail about that, because loads of people inquired about how to get that nice softer lighting. So I’m going to do a whole segment on that, I think it’d be cool for everyone, and also how I can do it for way cheaper than buying it from some other places. So I’m going to show you the sort of the DIY method of how to make the softer lighting and save you lots of money at the same time. A dental photography tip for the Protrusive Dental pearl for today, which is when you’re taking your portrait photo, which is important to do. And I think with more experience, you realize the importance of it as you go on. And if anyone’s doing orthodontics, you’re probably used to taking portrait photos anyway. So when taking portrait photo, especially with a ring flash, which is the most common flash that people have for dental photography, the lighting can be quite harsh. So if you can just very simply unclip the ring flash from the lens and pointed up towards the ceiling. Now most people have like a white ceiling pointed up to the ceiling. And this will really enhance your portrait photograph, it will make it much more softer lighting enhanced the features. So that will be my Protrusive Dental pearl point the flush to the ceiling, not directly at your patient. The other two things I want to tell you is that I’ve added one more book to my book list, which is protrusive.co.uk/books. And this is the Danish way of parenting. Again, if you already follow me on Instagram, you heard me on my story, talking about the lessons I learned from this book as a father and how Danish people are the happiest in the world. I think it’s because they have a really happy upbringing. So what lessons can we learn so I recommend that as a book on my book list, and the last thing I’m gonna talk about before we jump straight to the podcast is for those of you who missed my butterfly effect webinar that I did for the deanery. That’s now online, and you can catch it on protrusive.co.uk/butterfly. And this is about a little bit of my story about how I always wanted to be a restorative consultant, how that was my real focus. But then, you know, life happens, life comes in the way and how I’ve navigated my career path, and how I do believe that little things small influences, compounded over time can change the trajectory of your career. So it’s all about the butterfly effect that little changes and how they may result in big changes in your future. So check out that free webinar online on protrusive.co.uk/butterfly, and let’s jump straight to Andy Toy’s Part Two with PGO. Hope you enjoy.
Angles and [ ? ] and go continues on from there. Yeah [Andy]
Yeah, it’s part of the structural School of orthodontics. Okay, what I would say, and so when I try and make a difference for people, I say, well, you either, you know, this is a structural way of looking at it, we have a functional way of looking at it. Okay? [Jaz]
But Andy, most specialist would call that if you say to a specialist, well, in this case, we can accept the degree of class two in this case, they would then say okay, so you’re going for a compromise treatment plan. And that term then makes you almost undermined your entire thought process and what you’re trying to do for the patient. [Andy]
Right. And so, we have the evidence to show that the compromise, so called is actually the best way of treating this patient. Because I’m going to give you know, probably because we’ve been going on a bit but I’m going to give you what I think is the killer piece of evidence. Okay. So, Ron Presswood is busy Working through all this stuff, I tell you part of the story here that really got him onto this was he’s at a party. And a patient of his comes up to him and says to him, Ron, my son has just been to the LVI, Las Vegas Institute. He’s had his mouth restored, he’s in terrible, terrible pain. Okay? And can you do something? So Ron basically goes to see, takes the guy to his practice that evening. And in the LVI, on what they do now, to be honest, because I don’t really look at them. But what they used to do in though in those days was they would fit all these muscle monitors on there, they’d get used as a so called point of neutrality or whatever, [Jaz]
They still do that I’ve seen that firsthand in practice, [Andy]
Okay. And they invariably, then you had to open up the bite by six or seven millimeters, and you needed 28 units of crown or bridge, okay? [Jaz]
And what they done with this guy opened him up, and they locked him into this position. He was in terrible pain. So what Ron had to do was basically grind away all these, this poor sling and free him up, okay. And Ron is like, incandescent, at this point, because he knew this lad he’d been a patient of his, he’s part of the family, and his mouth has been wrecked. Because people are following this model of occlusion that the LVI were proposed at the time with so called evidence that we never see. But he says, Well, I got this other idea, but I don’t got the evidence. How can I go out there and say, you’re wrong? Well, I’m, it’s just my opinion. So that really what set him on the road to really, really work on the evidence. So you, you went over to Australia to work with anthropologists over there went there three or four times, the anthropologist in Australia got masses of evidence, but they’re not their academics. They’re not clinicians. So it doesn’t really flip over into how we translate their evidence into practice. Okay? Anyway, he’s talking about this with his son, Ron Jr. Ron Jr. is an engineer. In fact, he’s a space engineer, because he worked for NASA. Ron’s from Texas, he lives in Houston. So he’s saying to Ron Sr. saying to Ron Jr. He says, Well, you know, what, there’s this relationship between the way the condyle works and moves, and the way the teeth glide over each other. Okay. And Ron, Jr. says, Well, if that’s true, then we should be able to find the mass that describes that. So and Ron Jr, had been working on actually at that point, the docking mechanism for the space station modules, okay, which is a bit like a cusp going into a fossa, if you’ve been and through space, these two bodies are moving, okay? And they got to understand how they’re going to join up together. And there’s a mathematical relationship for that. So they go off to the University of Texas, they get 12 skulls from the anthropological department. And if Ron supposition is correct, then the occlusal surfaces of the second molars and the functional surface of the joint, okay, which is called as tubercle. And actually, they looked at the canine on the opposite side. If they are have a relationship, then you should be able to find the mathematical relationship, mathematical equation that describes that, because Ron’s idea was that as the condyle moves, you know, when you tried when you’re chewing and everything, all that is in contact as well, and you may well have a contact over on the canine as well. Everything is in harmony, okay? So they take 12 skulls, they have to build an extra powerful computer [M] days, and they did a digital scanning of those three points. They gave it to a friend of Ron Jr, who was [Ed Hankel.] He is another NASA Space engineer. And he basically did the scans. And they found the equation that links the functional surfaces of the joint to the functional surfaces of the teeth. Now, I don’t care about what your sciences but when you put an equation in there, that it to me is proof that you should have a posterior guide that it matches the condyle motion of the in the joint. So we have the equation that proves this. One of the frustrations for me is I can’t but we have gone to the articulator manufacturers, okay, especially the digital guys. I would say you know what, guys, if you gave us a cbct and we find two of the points, we can match all the other points because we have the occasion the Regional data, and it’s nonlinear maths. And the guys [at ankle] said done it, he did it all different skill sizes, he said, 12 is enough. This, you know, there’s enough synchronicity here that everything comes together. So we talked about evidence, I’ve not seeing any other model of occlusion come up with significant evidence over nevermind our own clinical experience that we get just as you’re describing. So, you know, going for a, the patient’s present occlusion, okay? The occlusion, they walk in with providing that the joint is healthy, and they can chew everything and they’re not in discomfort, I think we’re obliged to keep to that occlusion whenever we can. So it’s not a compromise. [Jaz]
That’s really fascinating. I mean, when you told me that story the first time. And then when I read your ebook, and I looked into it, and I saw the skulls. And I learned what a Centrum was because I have to admit, it’s not so much the spoons and stuff. So it is certainly very, very interesting. And the fact that you have, you know, your comparison of the evidence that you present against what the occlusion world presents the moment, I totally get it, because one thing that I was always taught, but my mentor and principal Hap Gil, who you know, a fellow a Hanky Pankey yourself. And he was telling me Look, Jaz, all this occlusion stuff, there’s actually you have to reverse the respect, there’s no evidence for this stuff. So that’s why I was also very open to what you had to say, because I know that the evidence for a lot of what we apply, doesn’t exist. [Andy]
Yeah. So always, as good clinicians, right? I know Hap’s like this as well, you have to take all this in, just like I did as well, and you’re gonna try it out on your own patient. And when you try it out with splints, then it’s an irreversible manner. And I know Hap, and you know, you were seeing that how actually, what you see is, suddenly occlusion becomes more simple. You have to work less hard, because all you got to do is make sure there’s good posterior guides. And all that work, you do not the front of the mouth. As long as you don’t get too much of a clash there. Okay? Then, life becomes much, much more simple. And you can, canine guidance isn’t a bad thing. But it’s not essential to a healthy functional bite. So that makes life a lot simpler. So good. occlusion is really very simple. Which is bad for me in one way, because if I made it really complicated, you could pay me a lot of money to come in give you five days [Jaz]
your tax bill would be would be one page, because literally the last minute of what you said there is essentially the crux of it. So I think my opening snippet to the podcast episode will be exactly that 45 second, what you said there? So is this a good time to now for me to then ask you some questions, which a lot of people might be thinking at the moment out there listening to this people who’ve never come across PGO I mean, I think I will try it out on splints, and go from there. But it’s interesting, we, you know, we mentioned about Hap Gil and one of my first experiences is when he gave me the job offer to work with him. And I went to shadow him a few times. So he was just finishing up an Invisalign case. And he, you know, removed the attachment, and now he’s checking the bite. And okay, right. Okay, I know what he’s gonna be doing here, watch. So checking the bite. And it’s a young female, and she’s now excusing left and right. And you’re a very long way away from canine guidance. There is no canine going saw. And I saw him do his thing. But of adjustments, check. Okay, everything feel smooth, good. Okay, fine. We’ll talks about retention and the patient goes away. And me, you know, I respect Hap very much even now, of course, more than ever, as our relationship has grown over the years. But I said to him very sheepishly like, ‘Hap, what about canine guidance? Aren’t you worried there was no canine guidance? And he said to me, ‘Whoever taught you all that rubbish, just forget it, you know. There’s no evidence for that stuff.’ And that’s what really got me thinking, no, I was already very much into occlusion. And I’ve been more and more and I love respecting and listening to all the schools of thought. So thank you so much for sharing the origins of PGO the origins of the structural viewpoint of occlusion which is important to know that actually, it may have started from a dream in 1884. So very fascinating to learn that. So now let’s talk about real world and how to apply it and some of the questions we have. So the first question I have is do about definitions, right? Function for me is in my map of the world, at the moment is a function is or masticatory oral function is speech, swallowing and chewing. That to me is function. So in speech, speech to chewing and swallowing. [Andy]
Yeah, of course. [Jaz]
So in swallowing Yes, that we need, we need a contact like MIP or whatever. So to build a solid says contact during swallowing, there is no contact during speech. Unless you’re, there’s some degree of parafunction going on that sense, and chewing. There are some fleeting contacts. But for my understand that there shouldn’t be any hard or significant contacts while we’re chewing. Otherwise, it’s a lot like when you’re walking up the stairs and you miss a step and suddenly feel a thud, you’d feel like that. So when I was reading your ebook, and I was reading the slide you very kindly sent me over while I was doing the last couple days. There’s a lot of and the way you mentioned it was about, okay, are the functional movements but you see in my map of world that doesn’t fit into the functional movements, because it doesn’t fit into what I just said, there. So what do you mean by these functional movements, and when you go into the, in a high force, and you grind back to the middle, that shouldn’t happen in normal function in chewing is what my belief is. [Andy]
Yes, so the, there’s two aspects of that, firstly, you do get these fleeting moments, fleeting contacts, okay? And so you want to make sure that there’s not a tooth that’s in the way. So that’s where the freedom thing comes in. But there’s an important thing, and that is something called the healthy clench. The body needs a chance to fire those muscles, without the teeth being in the way and the condyle seated properly. So the pipe, the purpose of the splint is to enable those muscles to fire and to have the healthy clench. So there is a time and I don’t know, I’ll be honest with you, I don’t know how much it is people might have done research on it is but there is so many times in the day when you do need to clench and be able to move around a little bit. Now I got an interest experienced in myself, this is a research study of one, okay, because I had my Invisalign done, I wear my vivera retainers. And I can tell you and this wasn’t a name of treatment, but I went from about 35 millimeters opening with a deviation to one side. By the time nowadays I got 40-45 millimeters opening, no deviation, no clicks, get out like one here. When I take my viveras out in the morning, I can’t feel my back teeth touching. Okay. Now then, I was just waiting for, you know, my mouth and my head to explode. Because I didn’t get my back teeth touching, they generally come back during the day. One of the things I realized is actually your, your bite changes throughout the day. And I go back to my osteopathic and chiropractic friends and I say what it’s all about, where’s your jaw, jaw posture and muscles change and fluid balance change and things like that. So one of the things about a functional approach is you don’t get too hung up about the actual contact, but you do want good function. And what I think happens is when my viveras are in during the night, I’m doing a bit of clenching. It’s really time that the muscles here the functions really improved. And the fact that I can chew without my back teeth actually touching because I could chew everything all day, no problem. And so it’s that it must be that at night, I’m just going to the gym a little bit. And I’ve got a nice posterior guided occlusion, good contact in the centrums. And everything’s fine. So I think that there is a certain amount of time during the day or night during during the 24 hour period when the patient should be able to get into that centrum, that little spoon thing there and just grind around a little bit. So we call it the healthy clench. And this is one of the other things that you know your average approach occlusion says you must stop clenching, and grinding is bad and stuff like that. So can I tell you just one little bit about bruxism then [Jaz]
Please, this is gonna stimulate debate about bruxism and parafunction because because you were hitting all the right points, you know, I’ve come from a background where parafunction is bad. The teeth shouldn’t touch is essentially the background coming and then what you’re telling me now and it makes sense, because to be fair I spoke about the episode Barry Oulton, Barry Glassman is that we’re all complaining nowadays that so many of our patients are parafunctioning. And sometimes I think Hang on a minute, maybe that should be the norm because if patients are parafunctioning, maybe it’s the 10% who on that the abnormal. [Andy]
Yeah. So for instance, or Okay, so a certain amount of wear is normal. That’s one of the things no, we don’t get this in the UK so much but In the US, you know, if you had, I don’t know, you’d lost like a millimeter enamel or something that’s a reason to restore the tooth because it’s not looking like a virginal tooth. Right? And if they can crown it, they’ll do it. That well, that’s the way they are. And [Jaz]
I’m sorry guys who listen this in the States, but it’s kind of true. [Andy]
You know, well, I’m talking about the 80s 90s you know, go to pankisi some fantastic dentists and doing brilliant preps. And this is the way we thought you know, every tooth must have that cusp to fossa relationship and all that sort of stuff. If you look at the anthropological evidence, you will see that teeth are designed to wear so some wear is normal. And if you think about what is a equilibration it’s really just advancing the wear a little bit that we should have had if we were on a proper natural diet. Okay. So there are a little bit of freedom to move around that a little bit of wear is a good thing. So that’s part of it. Where was I going to? [Jaz]
Bruxism. You mentioned bruxism? [Andy]
Bruxism. Yeah, right. Okay. Now then. Ron, I assumed that bruxism was something to do with up here. Right? I think in it’s not really anything to do with occlusion people brux is someone who some has gone on, you know, a mentally, emotionally or whatever it is. And I start talking to Ron, he says, I actually, you know, I find that when we give them the posterior guided splint, the bruxism stops. Okay? And I think it’s because what they’re bruxism because there’s something that’s in the way, and they’re trying to get rid of it. And as soon as we get rid of that noxious contact, and if you think about the way they adjust occlusions they’ll say, is there anything doesn’t feel quite right feels like it’s in the way just here so they adjust it? Yes, please. That feels better what you’re doing with equilibration, just giving them some bit of freedom. Okay? So anyway, we decided to do a study on this at [ ? ] University. And we couldn’t this is interesting, we couldn’t recruit a single student to this study, because what we want to do is give them a canine guided splint, right? With sort of moderate steepness. They’re going to wear that for 28 nights, then they’d have a rest for 28 nights. And then we give them a posterior guided splint, so no anterior rump. And just to mix it up a bit, they may start with the posterior guidance plan and finish with canine guidance splint. Anyway, [step four] is to go through a lot of students, not one single student was willing to have any dental procedure done, even though it was a split. So I had to recruit 12 FTS, right. [Jaz]
Is it because it’s not sexy to wear a splint? Is that what it is? [Andy]
They were happy to have stuff put on their muscles and different things. But they were not happy to go and have impressions and stuff like that. So I had to recruit 12 FTS. And Fortunately, we got them in. And we went through the study. We tried to show, we tried to do sort of laser imaging of this splints to show the different wear patterns. It was a failure. Okay? We couldn’t get decent data out of that. They did show like we expected that in the canine guided splint, you know, when he moved off to one side and the other the muscles switched off. So we could show that. But the other thing that we did is we took photographs of the splints. So we then compared the wear patterns on the acrylic of the canine guided splints, and the posterior guide splints, okay, because you can tell you know, once they want to spend for 28 days, if they grind in, you can see the effect of the occlusal contacts on the anatomy. And we also asked them, we gave the subjects then a questionnaire to fill in about comfort and stuff like that. So there was no evidence of bruxism on the posterior guided splint. And on every canine guided splint, they’d been grinded up and down the ramp, because you can see the acrylic had been worn in because we compared the photographs of when we fitted it to when we looked at after 28 days. And 11 of the 12 subjects reported better comfort with the posterior guided splint, and the other one was neutral. So to me, it was strong evidence for Ron’s assertion that if you will grind your teeth if you don’t have good centrums, good posterior guides, and you could well be grinding because you’re trying to get rid of something. Yeah, now I know that invariably now when I get sent a patient from a dentist to deal with their a TMD quite often they’ve had some anterior dentistry done in some way. And they’ve restricted the path of motion. And so they’re not got that contact at the backs that they used to have. And they’re starting to get problems. Okay? So it’s usually the dentistry looks too good. And it’s too anatomical and is not functional enough. So that’s one of the reasons you know, we talk about in the diploma, you know, overjet’s your friend basically, building two or three millimeters overjet, give them some freedom in centric as sort of a [Pankey.] So, there you go. So, I know I wouldn’t say hand on heart that every parafunctional situation every bruxism is due to an occlusion issue. But it’s certainly significant. And I and Ron being a Pankey dentist, he takes photographs of his patient’s splint year after year after year, and he’s got photographs of people, you know, came in with massive parafunction. 20 years later, their splint looks just the same, no grinding. [Jaz]
I respect that a lot as someone who takes photos while splints. You know, as many of my listeners know, I get a Sharpie pen, I color my splint in and I can see the patterns. And to fair 80-90% of the splints I’m doing is anterior only whether it’s b-splint, FOS, NTI. So this is why I’m excited to be exposed to this type of learning. But what you said there about how one might want to grind away that canine guidance because isn’t the way and I simply I completely see that. But it’s funny how in those lectures by the “occlusion gurus”, you see, we all seen that case where they say, Oh, this patient, we need to restore them because they’ve now lost canine guidance. And now they’re parafunctional on their posterior teeth. This is really bad, the forces are high. And the very crux of occlusion is let’s rebuild, let’s anterior rise, this occlusion, and it’s just so why is it, Why do you think that we dentist yourself even when used to do Tanners and Michigans, how can you attribute the success that we can get from doing anterior dentistry? [Andy]
Okay, so what does the tanner applaince do? And we I’m talking about a flat plane appliance, pretty flat here. That’s the way that we were taught at Pankey. I mean, it basically opens them up. And allows them to move around a little bit. And when they clench that posterior guide comes in. I’m not checking for that. Because when I was doing the side to side, it was just gliding movements. So it’s just back to be Ron’s work in 64. So the point is, 100% of people have posterior guides. That’s what we found on those dentists, even the ones that have been equilibrated. Okay, so, the reason that the splint has worked is because we open them up, and we allow them a bit of freedom, and it’s flattened it all the whole thing off. And I don’t, I’m not going to get into this right now. But there’s been a bit of work done with the denture system that’s come out of this. And this is where [John Bill] comes in the denture technician. When you open up, you know, with dentures, you can open up the vertical. Okay? I’ll tell you a little bit about it. You know, I don’t know if you make full dentures anymore. I made when [Jaz]
I make about two or three a year. [Andy]
Okay. So, you know, a good full denture On what basis is it made? Curves of spee and wilson? [Jaz]
Yeah. That’s what we tend to follow. [Andy]
That’s right. Now, what is the radius of the curves of Spee and Wilson? [Jaz]
Radius. I’m gonna say it’s based on the work of four inches Bonwill’s triangle, right? [Andy]
It’s four inches, right? So they set up a denture occlusion based on Bonwill’s work. And the denture occlusion is symmetrical. And it’s a linear movements, and you’ll put an end to a nonlinear system. So John Bill’s a denture technician in Leicester. He’s my denture technician. He’s always trying to solve problems. And one day he comes to me, because he’s working with a dentist and he was setting these dentures up in the most perfect occlusion. You could even set up he put them in the mouth at a slide from side to side, and they’re flipping all over the place. So we grind them down, grind them, we grind them down until they stopped moving. Okay? And he found it was steeper, the occlusal plane was steeper on one side and flat on the other. It was asymmetrical. He comes to me. He says, “You know about occlusion. I’m grinding them down like this from the perfect curves. And I find it steep on one side flat on the other. Is that right?” I said you got to meet Ron, because Ron had found the same things on the dentate patients. And as a result of that with Ron Jr. They developed a whole new denture system called CQR, okay? And the occlusal planes of the dentures match the patient’s own asymmetric condylar movements. And when you get that, you get absolutely stable dentures. And did I direct you to the site which showed the videos on that? We’ve got videos to show you can [Jaz]
Are you happy to, for the viewers, listeners and viewers of this podcast to I’m sure we’d be happy to share the ebook. But my listeners love downloads. So if you’ve got any videos, that sort of stuff, they will loyally watch it because I’m sure they’re you know, people listen to it are generally interested in parafunction, occlusion, different composites denistry and all [Andy]
I get that because we’re the same. And the thing about showing it on a denture is you can immediately see instability, right? And the thing to get your head around is the occlusion on a denture, functional occlusion in denture is the same as functional occlusion in the mouth, on a dentate patient. And when it’s unstable on a denture, when the occlusal planes are not in the right place, the denture moves, you can see it straight away. When it’s in the mouth, you don’t see the teeth moving is what’s happening up here that you don’t see is unstable. Or maybe there’s some fracture and forces on the teeth. Or maybe the periodontium is getting stressed, we can’t see it. But you can’t see it in a denture. That’s why I often show the denture videos to help you understand what’s happening in a dentate patient. Anyway, what John Bill understood, then when you start, we start to build these dentures with functional planes that match the patient. As you open up the vertical, the steepness of those curves changes. Because actually, you’re on a different part of the condylar surface. So what happens if so in his average sort of facial height, he said, it’s steeper on the right than the left, and we haven’t found anybody yet it was the other way around, okay. But as you open up the vertical, it becomes much flatter both sides. So what do we do when we put a splint in and put a flat plane splint in we’re basically creating that we’re allowing them to move around, and they can really then free up the muscle start working. And when they really clench that little posterior guide comes in. That way, I think the splints work. [Jaz]
I know that was a good answer. That was not like a politician at all. I asked the question, why are they successful, I think you’ve answered that in a different way. And is back to what we said earlier about a different way to explain the reason why we see success in what we do. And I appreciate that. How are we doing for time? And because I’ve got some more questions I’ll be doing okay? All right. So you mentioned about the muscles having a the correct amount of function the correct I mean, the How is it that you worded it in terms of the muscles being able to contract in a coordinated manner? And with enough volume, would you say, or, how do you? [Andy]
Volume of contraction, maximum contraction, that’s what the sEMG measures? [Jaz]
Sure. What I what I do is, as part of every new patient examination, myself is I always palpate the muscles of examination, and I make a note of the degree of hypertrophy. And I had to have either quote, say, their normal what they feel to me, or if I feel a bit of a bulge, then I said, Okay, they’re mildly hypertrophic. And if I feel a bulge of the masseter, that’s, let’s say, more than three or four millimeters now I’m being like, you know, subjective here. And you know, those patients very square Jaws, really severely hypertrophic masseter. Well, are they all normal? Or is there at what point do you say okay, this patient is, you know, some you get this very thin, slender ladies in and they bite together. Are you biting together? Yes, I am. But you can’t feel any contraction, whereas others you feel a massive buldge. So what is normal? [Andy]
Well, let’s take it away from dentistry. And look at the people walking down the street. Okay? They’re all walking perfectly happy, healthy, can do whatever they want. Some of them got tiny little muscles, some of the got big muscles. To me, that’s a structural point of view. Things from a structural viewpoint. Okay. I’m more about the function. So one of the things that I do, and generally this is with TMD patients, you know, when I’m one of the reasons we’ve not done research on patients in pain, because pain is complex. Let’s remember that pain is actually felt up here. So whilst they may feel it’s their joint, their tooth, their neck, or whatever it is, they may actually be nothing wrong with those it’s all up here could be that. So I need to sort of determine is there an occlusal element to this patient’s head or neck pain. So all I do is I get them to clench. And I do my own sEMG just like we did then, and I feel any movement. I do it up here as well. Okay. I then put some cotton rolls in and I see if the volume changes Because I’m more interested in the volume of movement, and the coordination, rather than the size of the muscle. So that’s a functional point of view, rather than a structural point of view. [Jaz]
Sure. Well, the reason why I’m so hung up on the size is because I do believe in something I feel I do observe is that for those who have larger muscles and are parafunctioning, they are destroying their teeth more, they’re able to generate more loads, I’m getting more fractures of crowns. And I’m using Zirconia instead of Emaxs or gold in those patients. So it informs my dentistry in my approach, these patients come back. And they’re the ones who are breaking the splints, for example, because they’re the strong muscles. So that’s why I can sort of relate it to maybe not function, but the power function. [Andy]
Yeah. Okay. So but what I would say was, I’m more interested in the volume of movement, rather than the size of the muscle. And it’s an it’s a useful tool as well, actually, because one of the things that we have to do particularly with a pain patient is we, we have to build trust with them. Okay. And I’m sure that the more they trust you, the more the pain goes away, frankly, that’s part of it. But I say to them, I need to try and work out whether your bite makes a difference to your to the muscles. And if it does, it’s possible, but it’s part of the problem that you have is problems with the muscles here and the joint not being stable. Okay. You tend to get pain from muscles that don’t work rather than muscles that do work. Right? So just be aware of that as well. [Jaz]
I do. I think I’ve observed that because people who’ve got these hypertrophic muscles, their muscles are not tender, you know, I do palpate them and then right, then sell them tender. [Andy]
Right. So I mean, I broke my arm in the past. And I can tell you, you have to hold it still for like, three or four weeks, I’m desperate to move those muscles and the muscles that hurt the ones that you can’t get working. And there’s good evidence to show, you know, a healthy muscle has good blood flow through it. And the painful muscle doesn’t. So that’s all another thing. We want movement, we want function, okay? So I get the patient and I say, okay, you test, let’s test, you know, you’re now getting to put their hands on the temples, because it’s usually the temporalis that doesn’t react, and I get them to bite together. And they can feel maybe it goes big, big like this, okay, or is fluttering on one side, okay. And then I put the cotton rolls in. And we see if it makes a difference that often is going to work. And they go, Oh, that made a difference. And my assumption is, when the muscles do this, then they’re going to be healthier, less pain, better function, then when it’s doing this. [Jaz]
That makes sense. Someone who respects what physios do, and like you said, osteopath, and stuff, you know, that’s very much the functional matrix. I can see that viewpoint. [Andy]
So so that’s what I’m testing all muscles. I do test with trigger points as well. One of the things I would say to I don’t know, I’ve never seen you test a muscle or work with a muscle. But one thing I’ve learned from the physical medicine people, particularly cranial osteopaths is that, you know, we need to develop a real sense of a real light sense of touching our fingers. We tend to use metal instruments. And I’ve seen dentists really squidging around here. But typically, that’s particularly rough on a TMD patient. I just go in, I’m feeling the quality of the muscle in that and you’re sort of tuning in. And if you touch them, and they feel pain, it’s pain, it doesn’t matter that it’s all up in here. It’s still pain so. And I’ve learned I’ve learned a lot from Ron Presswood here, you know, Ron is in his mid 70s now. They’ve got locked down in Houston. Do you know what he’s still working? He’s still working, because he gets two or three referrals every week from local psychiatrists, and MDs, and people are allied with people in pain. And he’s worked out I can see these people on my own. And but you watch how he and his team handle somebody with an extreme chronic facial pain. And you recognize there’s a lot around the people management, as well as what he’s actually physically doing with them with any sort of splint. So, you know, this is why we now research people in pain, because that is so complex. But, and you have to understand the nature of pain. But there are, there is a connection between the occlusion and the function of the joint. And there is a connection between the occlusion and the functional muscles, we know that we proven that we’ve got the equation, and we’ve got the data to show that so that can affect people in terms of their pain as well. And remember, I’m coming from the 80s when you know, good research has shown there’s no connection between occlusion and headaches. Right? That was the best research that was out there. Well, they’re wrong. There is. It shows inadequacy in that research. How do we get onto that? I can’t remember. Well, you’re talking about muscles and parafunction. [Jaz]
Yeah, I was talking about how strong is strong, or I know these patients I’ve got with really large masseter that worried me. They worried me because of Oh, gosh, they’ve already broken this cusp. They’ve already got a virgin premolar that’s now, a lot of photos on my drive of virgin premolars and molars that get vertical root fractures. And all these patients have one thing in common with a couple things common, they’re parafunctional patients, and they’ve got significantly hypertrophicmasseter, in particular, sometimes quite often temporalis as well. So sort of mean to that I want to switch these muscles off is what I’m trying to say to Andy like I did to let them go in it did the thought of them running free and wild on those large muscles, it to me is going to result in another vertical roof fracture with the view point [Andy]
Let’s think about it, right? First thing I’d say is, is it both sides? Or is it one side? Because if it’s one side, there’s I would say there’s some sort of contact there that they’re really working that muscle. Remember with these, okay? That the masseter work, even when there’s just anterior tooth contact. It’s actually this anti temporalis that’s not working. And if they’re fracturing teeth, I wonder whether that contact, you know, the occlusal contact is on a steep angle, and there’s no freedom to move around there. They’re trying to get that freedom. If you open them up and gain more of a Centrum to work on at the back. I wonder if that would be different. I wonder if they’d stopped bruxing, I wonder if they stopped working on you know, one side of the mouth. So they get this massive muscle on one side, that things would start to balance it. In fact, I’ve had probably I’ve got 8 to 9 Invisalign patients, I’ve had four with any sort of TMD issue, bearing in mind that I don’t treat them if they’ve got TMD, as a general rule. I had one patient come in once it was in my early on in my Invisalign days. And she said, I’ve got this terrible swelling on one side, okay. And I looked at it and there was nothing wrong in the mouth. And she’s basically got this huge masseter. And she’d been wearing aligners for about six or eight weeks. So I was looking, I thought, wow, why is that happening on that, and I saw her, flew right over to one side and really clench on it. And she had a bit of a habit. I said, Oh, okay, she was a gym bunny type as well. And she was playing on one side. So it was a time I was working with a number of people. So I showed him pictures and stuff like that. I said, Oh, what am I going to do? You know, I built this muscle up. And he said, Are you simply stop them working on it, it’ll go back to normal. So she learned not to do that. And she was fine. So they’re working that muscle, but I work. So I wonder if it’s both sides, number one, and it immediately tells me they haven’t got freedom in centric, you’ve got contact on steep occlusal planes to create that the force has to do fractures. Now, when we talk about putting the contact to the back, if I’ve got a tooth that’s heavily restored, okay? I’m not going to stick it all on a weak tooth, I’m going to bring it on other teeth as well, you got to apply a little bit of sense here. But as a general rule, if you can get two or three good contacts on the posterior teeth with a centrum, right? That spoon and they’re got freedom to slide up and down on that guide. And that is genuinely a guide is not too steep, in which case it becomes an interference, but you’re taking either, okay, then I find that they say yeah, I’m happy. That’s what I do with my splints. And also, I finished an Invisalign case. [Jaz]
How many Centrums do we want? [Andy]
I’m happy with, you know, if I can get it on two molars. So that’s four contacts on each side, basically. Okay, all four contacts so that will be enough. If the patient tells me they’re happy, I’m happy. [Jaz]
So I’m just retry that tangible. So if you talk teeth me, so for example, if we have upper left seven and lower left seven, and as the patients are going into sort of a heavy sort of clenching and in an excursive movement, and they’re now going to have a nonworking side guidance or a Centrum on the contralateral, let’s say they could have it in the first molar because it’s so the second molar may be heavily restored. So now you’ve got four teeth touching, and potentially two centrums being formed. Is that enough? [Andy]
Okay. See, I’m trying to think of the practical aspects of when I’m potentially gonna be working with splints and stuff. And then a lot of people might be thinking, Okay, I want to look for the Centrums in my own patients, where can I start looking from? [Andy]
Because I don’t feel a need to go in and alter the patient’s teeth too much. I certainly don’t want to be building up premolars to big contacts or grinding them down. Unless there’s a good need to do it because of the weakness of the teeth, or the periodontal ligament or something like that. And I come back to what we said at the beginning, you patient driven in your equilibration. Just keep going, until a patient says that feels comfortable. And you don’t need to look too hard. And frankly, Jaz, 98% of our colleagues don’t look at all, do they? Let’s face it. And if you don’t look, you haven’t got a problem, right? [Jaz]
It’s true. [Andy]
And the patients are okay. Because another thing that comes out of the anthropological evidence is the joint adopts to function. Right? So as long as you get them fairly comfortable, the joint will adapt, they’ll come back. In the old days, you know, you fit a crown on the NHS, you really short of the time is really high, you take the patient come back in three months, if it’s still a problem, they never come back. It all adjusts find God. And that’s what gets us out of trouble. But that makes me less anxious as well, because I’ve just got to make sure they’re comfortable when they leave. And I do. Personally, I do take care with them at the end of Invisalign, because I’m known for occlusion in my area, and I’ve got to do it right. The other thing is, I work in a practice in Melton Mowbray, there’s nine other dentists there. And most of my patients come from there are their patients. So anything I do is checked every six months. And if there’s ever a problem, they’re straight back to me, obviously. And I’ve been there for 10 years now. And I finished everyone with a posterior guided occlusion. And I can think of two patients have ever come back. I see their kids, I see their family, I treat them, they are happy with the occlusion I’m finishing the one. It really is simple. You don’t really have to sweat about it. [Jaz]
Well, the reason I say I respect that coming from you is because because of your diverse background in the different schools of thoughts that you’ve gone to listen to, and you’ve done probably hundreds, maybe even 1000s of let’s say Michigans, Tanners in the sort of structural school of thought, I’m sure you’ve done all that. And now you’ve made a switch some years ago to the PGO model. Are there still times where you would say Actually, I’m going to, for whatever reason, treat this patient in a structural way and give them canine guidance. Is that something that happens? [Andy]
Right, so I, you know, there are times what happens when they come away from the Centrum? They then go into canine guidance or group function. That’s okay. So, do you know Subir Banerji? [Jaz] Yeah [Andy] I mean, lovely guy. And he teaches on our diploma course. And he teaches a functional approach to occlusion while that’s why he’s there. And, you know, he’s talking about accepting what the patient’s got. And it was working with him, I suddenly realized I thought, Ah, what people aren’t understanding is that the centrum isn’t necessarily all of it, but it’s the first part of it, it’s the essential part of it. Where do they go after that? Well, I wouldn’t want them to go on to a heavy contact on a Periodont involved Central, I’d want to protect that central by them going on the canine, okay. Or if they’ve got heavily restored premolars or pre molars with fractures in, I don’t want them going onto that I’ll take them on to the canine. So there is then the next stage from that but usually then it’s only think of that stage they don’t realize there’s this initial thing all together and that is the essential. That’s the bit that’s present in nature. Right? We’re only trying to reflect what we know is present in nature. And nature does not give everybody dot dot dot stripe dot dot all. They doesn’t. [Jaz]
We know that from all our AOB patients that are breathing normally and surviving just fine I’ve got a great collection of AOB photos looks weird and wonderful ones and I do a lot I do load testing, I do the Rocabado Pain Map on them and they got nothing about his patients and and all that sort. [Andy]
What happened when they got though? [Jaz]
They probably have a PGO, they definitely have a PGO for sure. But yeah, they have these simple elements like the centrums but here’s the thing, Andy, I’ve not been looking for the Centrum. So I’m looking forward to lock down finishing and just you know, with a fresh viewpoint now might it look like it took you Andy some goes at it to you know, you followed Ron and listened to him multiple times before he said, Okay, I’m gonna give this a go. It might take me that sort of set. I might start with this video first. But I mean, I’ve always never chased canine guidance always. I’ve always said okay, for me, it was important for it to be smooth, everything should be smooth, less resistance in the muscle should be able to because the more resistance you have, if someone is locked in, that’s when the muscles really going to overdrive and I know that’s my sort of background, if you’d like as well. It’s not too far away from what you’re saying at all. Next question is you obviously a very eminent speaker in orthodontics, especially clear aligners as you talk in the diploma. So orthodontics is a full mouth in enamel, let’s say, when you’re now setting up your clincheck. I think you’ve already given a flavor that actually no, we don’t need to chase a class one and what these other orthodontist may call as a compromise, you can now accept as you’re going for a functional occlusion. Is there any tips that you could give to people setting up their clinchecks to get the right occlusal setup and occlusion at the end? [Andy]
So the first thing you do is you make sure they got a happy, healthy joint before you do anything. This is exactly what we teach. Now, you know, I teach Rahman a like, you know, he came from his school of orthodontics, which was over in Denmark. And you know, they were so wedded to class one. And we meet up together. And, you know, he talks about functional occlusion, I can remember actually, the first time I sat with him to teach occlusion, I was really worried because I come up with all this stuff. And you know, he couldn’t accept it all straight away, but it sort of made sense. And same as Subir. But one of the things that was so important to me about working with Rahman is, he think joint first. Okay? So everybody should think joint first. So the, my first touch with a patient, after I’ve listened to them on what they’re interested in giving them a mirror, and got it built a better relationship with them said, “Right, can I just check your jaw joint? Because my job to make sure that we give you a healthy functional bite at the end? It’s no good having a nice smile If you can’t chew properly.” And they go yes, you know what it is, the more times they say yes, the more they’re likely to take up their treatment. It’s the lightest touch, and I check their joint function. So that’s the first thing I do. So invariably, thank god 99% of patients have enough opening to chew, they might have a click, they might have a slight deviation, but it’s not really a problem. I mean, check in the mouth. And I’m not seeing any significant problems with occlusal wear, mobility, recession, fracture or anything like that, so that patient’s occlusion works for them. So I’m now going to try and maintain that posterior occlusion as much as I can. Because I’m unhappy with their occlusion. So I, as a general rule, I do not move second and third molars. I locked them on the clincheck. Okay? I will move first molar as if I want the width to get rid of the deficient buccal corridors, I need the width for space. And as another sort of general rule in terms of how I plan in the case, how much expansion do I want? Well, I go back to the second molars, they come in, there in [jam] where there’s a zygomatic arch comes in, and I want a smile at built that fits the face. Okay? So if they got really high cheekbones, wide, and they’re wide at the back, then I feel well, we’re gonna make it wider at the front as well. So I use the second molar as gently as my reference point for expansion. Anybody’s familiar with the four centers prescription that Rahman and I developed for Invisalign? Well, no, this is just absolutely comes in there. So I generally not move the second and third molars. And so you’re going to maintain your posterior occlusion, you can get intrusion, you know, with the molar of the aligners, [Jaz]
which is why it’s so good for AOB cases. [Andy]
There you go. What happens in at the end of my alignment, when I’m happy with a patient’s happy with their appearance, and then saying, right, we’re going to check make sure you bites okay. And I’ll ask them does anything feel like it’s in the way and it’s patient driven equilibration. Now, the one thing you got to check with orthodontic patients is their teeth immobile. So they’ll say, Yeah, I can bite okay, but what might be happening is they’re biting and the anterior teeth are moving. So they’re forcing those posterior teeth together. So I put my fingers on the front, or I get them to put the fingers on the front, and they can feel any of those front teeth moving, I don’t want that. So it tells me there’s a slight posterior open bite, even if I can’t see it. The other thing is I’ll do is I’ll put a little bit of 80 micron paper in there and get into clench. And if it catches, then that tells me That’s okay, as well. I finish about 60% of my Invisalign cases with a Dahl Appliance, because I’m not prepared for them to have any movement of the front teeth. And if I’m honest, I’m not that bothered about having any anterior tooth contact at all. And so if there’s any movement, or they don’t really feel like they can bite really well on their back teeth, or that paper comes through, I’ll get the last lower aligner, trim it distal to the canines and send them away using the upper aligner as a retainer. And usually I say it might take six to eight weeks, but over two or three weeks, those posterior teeth come together. Now, I don’t know if the anteriors have intruded, the posteriors super erupted, or whether the condyles changed, I don’t know. But they get the back teeth together and then I’m happy. Constantly asking the patient, Is it comfortable for you? That’s enough. I don’t really worry too much about what the actual contacts are. Because in function, they’ll be telling me if they’re in the way basically. And if they’re not in the way they can chew what they like. So [Jaz]
I really like that answer. So the answer is very well. So how Andy approaches the occlusion, so not moving the second molars and third molars and at the end, using the aligners as a dahl appliance, fantastic. And just a couple as well, [Andy]
One other point there is crossbite, I bit worried about crossbites as well. If I’ve got like molars in crossbite. And there’s no [hit and slide], there’s no functional issues, I’ll often leave a cross bite, there’s nothing to say, you know, you can get good occlusal function when the teeth are in crossbite. Because it’s that initial movement, that’s important, not the fact that it’s inside or outside class one, two, or three. It’s that centrum is important. So I will often leave a cross bite as well. [Jaz]
I tell you, Andy, I wish that I can think of a couple of patients where I wish I left a cross bit. [Andy]
Why make it complicated, right? [Jaz]
So true. Takes an awful while sometimes. Well, one thing I forgot to ask you is how important is for your patients to be in “centric relation” when all this is happening, how important is for the condyle to be the definition of the anteromedial port the condyle to be on the posterior part of the sort of articular eminence, do you, does it matter? [Andy]
What the hell is centric relation, right? So in our world, centric relation is a border position. It’s not a functional but necessarily the functional position, they actually function further forward than that in various positions. So the way if you watch, you know, I learned bimanipulation technique at the [Pankey Institute], they got this fantastic bit of kit, which, you know, shows you exactly where the condyle is and how much force you’re supposed to put on and stuff like that. And with some patients that works really well, other patients, they’re all over the place. So when you watch Ron do it, he’s almost, he’s talking him into it actually. And you will get, you’ll just put a little bit of pressure on their chin, and just get into open and close gently. And what you’re looking for is actually a muscle defined position where they want to function. Okay? And if it’s a patient with TMD, you might not find that straight away, because they’re all over the place. But you know, average, you know, Invisalign patient, for instance, and you check in if there’s a hidden slide, you just get nice and quiet, you try and get him to stop thinking about their teeth. And you put a little bit of pressure down, sometimes I get them to lift the tongue up. And that will just put the condyles in roughly the right place with the teeth not interfering. And then you get them to close together. And if their function defines the condylar position, that’s the point. It’s not you pushing them into a position. Now that people like centric relation, because it you can get back to it all the time. So but you lose the point of it. That’s not a bad thing to know. But it’s not their function. It’s a just the reference point. And it’s the back end of that functional area, if you like. [Jaz]
So what you’re trying to say is that, although you’re not too hung up on it, you’re still sort of when you’re maybe equilibrating for someone to achieve PGO you are trying to approximately get to Centric relation? [Andy]
Well, I’m aware of it, but I’m certainly not pushing them back. Again, I’m letting them drive me. So generally, if they’ve had a splint, the muscles balancer, okay, started work properly, the joint gets to where it wants to be. And then they take the splint out, you find the teeth are in not in the right place. So you’re basically then getting them to just remember where it was without the splint, and then show me where it touches and then they’ll tell you, basically, oh, yeah, that feels like it’s in the way. Because you’ve done that reprogramming, you know, of the whole neuromuscular job with the splint. [Jaz]
Fantastic. I’m just now checking if I got any more questions left. Let’s see. Okay, so the last question then and then I’ll offer it to you to put any final points if you’d like to. It’s very educational episode. I really enjoy listening to you, Andy. So the question is some schools of thought suggest that MIP is a pathological position. So that actually we shouldn’t, you know, our teeth shouldn’t really be touching. So if you look at the end, of course, you might argue that the quality of evidence not good. And that’s a very valid point. But the, I believe, is 1964. The Graf paper, which showed using the latest technology that had at the time was that our teeth should only touch for 17 and a half minutes per day. And even then, not much force and psychological like we said, as those fleeting contacts, whereas you offered a theory of actually, we need to have a healthy clench, which wasn’t mentioned in a paper such as that, for example. So some people say that MIP is a pathological position. And, frankly, the what contacts there are in MIP is not important in the non parafunctional patient. Can you explain your views and then also, freedom from centric or freedom in centric, at maximum force, but that is something that maybe only happens in parafunction, but I think you’ve answered that actually, that healthy, the healthy clench is part of health. So I think you may have already answered that. But what do you think about that view that MIP is a parafunction or sorry, is a parafunctional position itself? [Andy]
So I, to me, it’s what’s the quality of the contacts when they are in MIP. And if you’ve got contacts that are on steep inclines, and they’re locked in, then that’s going to create, we certainly know it’s going to create problems with the teeth. Okay, we know that those sort of contacts will switch muscles off. And remember, I wonder if that’s such an old paper, whether it’s coming from the old Tripodization philosophy. It’s actually a commentary on the old Tripodization philosophy. It was when, you know, dentist got so into their engineering that they believed that a good occlusion was three contacts for every cusp. Right? It will lock the patient in. And here’s another story. I wasn’t there. Ron wasn’t there. But Ron knew somebody was there. And this is the birth of canine guidance. Right? So this is high powered study club. And I can’t remember whether it was East Coast or west coast, but through the 50s. And 60s, there was like two battling schools of thought, east coast and west coast of the states. And one was about Tripodization. And the story goes that this dentist wife and the mouth restored by this top level occlusionist, okay? And she had gold on all our occlusal surfaces, ultimate, most jewelry, Tripodized contacts. And within a few days, she’s in terrible pain. So what they did was the ground all the contact zone, and the left with canine guidance, and she got better. And so Oh, she got better because of canine guidance. [Jaz]
Mm hmm. [Andy]
Whereas, if you took a functional point of view, no, she got better, because you gave her some freedom. You got rid of those tight contact. So I don’t know, Jaz, about that. But I wonder whether that part is the reason for that paper? Was to say you should not be locking people in. [Jaz]
Okay, that’s it. Yeah. I mean, you will never know. I mean, I’ve got the paper I can send to you. But essentially, is that you know, you must have heard that, you know, they’re 17 and a half minute chewers is that really, the teeth should only retouch when swallowing. So it’s a difficult, you know, it’s a lot of the background stuff that I come from. I mean, the other thing I want you to answer [Andy]
how do they measure that? [Jaz]
It’s a technique where they use some sort of laser or something, I forgot what it was now. It’s a term I’ll send you the paper. It’s interesting. This is widely cited this paper even is it you know, and I say, how often should our teeth touch together. And something I say to my patients, actually, you know, if you’re, so one thing I think we can both accept is that at rest, it should be lips together, teeth apart. So that’s essentially what I teach my patients, you know, that you shouldn’t actually be grinding clenching. That’s parafunction. I mean, I think it stems from that as well. What do you think about PGO? And does it have any similarity to the, you know, 60s and 70s, the balanced occlusion, is that different to PGO? [Andy]
Well, from what I understand, with a balanced occlusion, it was actually was a denture occlusion, and they’re saying that you should be and that’s why you had the curves of Spee and Wilson, [Jaz]
but they were applying it to a dentate [Andy]
A dentate patient. So I’m not aware, I couldn’t give you a decent answer on that. Because I don’t exactly know what they mean by balanced occlusion. I mean, I don’t think Ron and Henry came up with these ideas themselves, necessarily. They were part of, if you Ron’s written a book about Henry Tanner, and if you read about Henry Tanner, you know, he started dentistry 1946. And he was given the job of a equilibration in 1946. So, you know, they were all these competing theories all the time. So it may well be that this idea of balanced occlusion was around. But it hasn’t been described as fully as Ron and Henry have gone on to do it. And Ron has gone and got the evidence for it as well. And remember, you can’t get some of this evidence because the mass didn’t exist in the face. So you can see how these whole ideas have changed. And what we accept today as being obvious, isn’t obvious then. And we come back, if there’s one closing thing that we want to come back to New mentioned, if you say it’s your worldview, for instance, well, we are Oh, we’re talking about theory. Okay? Now, the purpose of theory, if you want to get back to scientific science, philosophy, the purpose of theory is to explain as succinctly as possible, all these different facts that are out there. There are facts out there that are not explained by a particular theory. And as the science develops, a new theory comes along, but not explains these facts, but can explain those things as well. And that’s the way that science develops. And I think now with PGO, we have a theory is not necessarily a perfect description. But it’s a better description of the real world than the theory of the structural theory, which explain that, you know, when you put people in canine guidance, they get better. All right? So that’s where we’re at. And this whole process is replicated throughout science. But as scientists, science students, we’re not taught about all those competing theories. It’s all about the one that becomes the truth. If you’re in social science, it’s all about the competing theories. And as I was teaching this social science education course, I recognize that actually, this whole thing around occlusion is just the same. And one day, possibly, everybody will see Actually, yeah, this theory, and maybe PGO explains more things to me and allows me to get on with my life, than the old theory does. And then as we develop more and more conversations like this PGO will develop as well and will develop into something else. But I think personally, we’re at a point where we not only have clinical experience, lots of our friends and colleagues not bothered with occlusion and patients aren’t queuing up in terrible pain. We have experiences like we have in terms of what you’ve done with splints. We have the evidence, like Ron’s audit, I did audit on his pain patients, for instance, how quickly they got better. We’ve got all his pictures of his splints, we’ve got our experiences that we do with, for instance, me finishing off these Invisalign patients over 10 years in this practice, where all my patients are being checked every six months by general dentists, just like you and me. And we have the dentures that show the effect on how changing the occlusal planes to match the functional surfaces of the joint makes an absolutely stable denture without implants. And then finally, we have the equation. And all those different bits of data facts can be explained by this theory. It explains all of those things, not one of those bits of evidence is enough to convince anybody that this is the truth. But you put them all together. And to me, it explains the truth in a much more complete and simple way than anything else I’ve come across. And that’s basically it. [Jaz]
Fantastic. Well, I really appreciate your time to share about the origins of PGO. And also look at the structural view, you’ve answered a whole lot of questions that people out there might be thinking, and if anyone wants to, you know, comment right in, and I can always send these questions to Andy. And if there’s any resources, please Andy email it to me. And I’ll put them on as part of the downloads of this episode. I think you’ve summed up very beautifully at the end, they’re almost poetic, but is there anything that you’d like to, you’ve got the microphone now. [Andy]
Well, only mainly to thank you, Jaz, for this opportunity, and to be questioned by you and challenged by you is a joy. And all of your listeners and people watching out there, come back with the questions. Okay? Because it makes it, the model needs testing, and it needs development as well. And but what I would ask everybody to do now is to understand that the way they’ve seen the world can be seen in a different ways, like a different set of glasses, and start to look at the back of the mouth as well as at the front and start to think about function rather than structure. And let’s keep talking. And let’s help develop these ideas. It really is should be simple, and hopefully will be. I really, really appreciate what you’re doing here, Jaz. Thank you. [Jaz]
No, no. Thanks for coming on, Andy, and as I said, in one, every episode, I start with something called Protrusive Dental Pearl, like a little tip, it could be dentistry, could be something else. And one of the pearls I shared maybe five or six episodes ago, was a quote from Malcolm Gladwell. And it was “There’s something very unattractive about someone who refuses to change their mind.” So I think I’m always open to, you know, I completely accept but my hands up that what I believe now may be different to I will believe in five years, and I’ve got no problem to change on mine as long as evidence where the evidence, like he says many arms, it’s a whole clinical practice arm of evidence as well. So I think everyone should keep an open mind. And I like to have discussions like this in the future. And I think this is how the profession will develop in all the ways but I think it was occlusion which lacks a lot of evidence, it’d be great to test PGO more and really look at the different models like we are social scientists as well. [Andy]
Jaz’s Outro: So occlusion geeks, thank you so much for listening all the way to the end. I hope you found it really useful. For those who haven’t downloaded Dr. Andy Toy’s ebook that was available with part one in the show notes on the protrusive.co.uk website. And again, like always a really appreciate you listening all the way to the end. Loads of cool speakers coming up. I’ve got Richard Porter on emotional intelligence. Got Zak Kara back again, as well as Gurs Sehmi talking both about presenting treatment plans and a little bit about you know, the whole case acceptance kind of thing. How can we actually get our patients to understand our treatment plans and go ahead with what we think is the best thing for them. Imminently, we’re coming out what about careers and actually making yourself employable. And also Ama Johal in airway, which is gonna be a massive, massive, very much a topic that is not talked about enough. So really excited to get that content out to you very soon. It does take some hours per episode to actually produce it all and get it all edited. So stick with me and I really look forward sharing that with you. Take care.