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Philosophy of Functional Occlusion with Riaz Yar – PDP066

Canine guidance is overrated. Read that again. Crazy, I know. In this episode, one of my mentors Dr Riaz Yar explains the rationale of a functional occlusion whereby the pillars are the central incisor and the first molar.

Dr Riaz Yar is SUCH a good Educator

I found some similarities to the Posterior Guided Occlusion (click to listen to the episodes by Dr Andy Toy) in that we place too much emphasis on canine guidance.

Need to Read it? Check out the Full Episode Transcript below!

Protrusive Dental Pearl:

There is no joy in mediocre Dentistry

Dr John Kois

I hope you find this episode stimulating – and if you are a true protruserati, you will be grateful for another point of view AND NOT be upset that we all can’t agree with each other, haha!

Stay tuned for STRAIGHTPRIL!

Did you miss out on SplintCourse enrollment? It will be relaunching in June – click here to register for the launch offer

Check out Dr Riaz Yar’s courses here – his book will also be launching in Q4 2021 – watch this space!

If you enjoyed this episode, check out Posterior Guided Occlusion with Andy Toy!

Click below for full episode transcript:

Opening Snippet: I just couldn't get it out of my head. It took, you know, years and years of reading and reading and reading. I just, it just never comfortably sat in my head. And so there was always this niggling doubt and it always hit me when someone asked me a question, you know, and the biggest question that always got me. If the canine tip's well, why would you give them canine guidance again?...

Jaz’s Introduction: Hello, Protruserati. I’m jaz Gulati and welcome to Episode 66 of the Protrusive Dental podcast. Are you feeling a little bit less stressed off that phenomenal episode where Manuela Rodrigues which was Episode 65, which is all about how we can be more mindful in dentistry. So thank you again Manuela for that. This episode, I had to just squeeze in occlusion one more time before we came to the end of March because April is straightpril. Okay? Doesn’t quite have the same ring to it as splintember but, you know, give me some props here straightpril is not bad. So it’s all about orthodontics. Next month, we’re gonna talk about retention protocols, the do’s and don’ts of aligners elastic in aligner therapy, and the whole GDP vs specialist debates. So we have a GDP, and specialist on so you get both perspectives. So that’s all coming in a few weeks very soon. Before we dive into the meat and potatoes of the main episode, just want to share some news with you guys some really cool news, the splintcourse enrollment, which some of you, many of you took part in, has ended and oh my god, it was phenomenal. I’m so pumped to have delegates from all over the world from Taiwan, Singapore, UAE, India, Australia, New Zealand and Europe. It’s great to have a real community of people who just want to learn about splints. And already we’ve got this secret Facebook group, everyone’s posting cases. And it’s a really special group that’s really engaging, I just want to share with you the feedback I got from the very first delegate who finished splint course his name is Nasir Javaid. And this is what Nasir had to say about the splint course, “What a brilliantly put together online course. This course is bursting with educational gems, patient videos, detailed explanations and easy to follow and digest format, you can tell a lot of thought has gone into preparing and delivering this course. And it’s directly relevant to everyday practice makes it most engaging. One of the most value for money courses I’ve ever done. Thanks Jaz.” Well, that is just spectacular. For my first delegate who’s finished it, what can I am just absolutely made up after that feedback. Nasir, thanks for being the first delegate to finish and since now I’m recording this five people have finished a splint course entirely. And the feedback is just great. I’m going to share it with you in the future again. But I want to get to the main bit of the episode before I do. The other bits of news I have for you is that I have had two podcast features, which I think I’m pretty proud of and I’m going to share them with you. One is on Dr. James Martin’s podcast, which is on money, it’s Dentists Who Invest podcast and if you remember many episodes ago, I had James on my podcast. And then on the back of that he made his own podcast, Dentists Who Invest, and it’s fantastic. Delivers a great value. And I did my bit on the podcast about how as dentist we should be thinking about other ways, other ways to sort of spread our risk because I sort of say that in our profession, the most stressful thing is that it just takes one issue, one complaint, one GDC issue or your regulatory body issue wherever you are in the world. And that’s your livelihood gone, right. So how can we diversify our financial strategies to make sure that we are bulletproof? So that’s what we discuss. In fact, I’m just gonna play a little snippet from that podcast, [James] Whatever it is that you can you’re supposed to be financially free at some stage. And maybe having a tangible point is very, very, very helpful. So another good message there. Do you think you’ll continue to do dentistry, Jaz when you reach that point? [Jaz] Yes, absolutely. Because I you know, I feel as though I want to be able to do that. And I think everyone should I think every dentist should aim for this. Right? If you can make yourself in a financial position that you do dentistry, because you want to and not visit because you need to. Wow, I mean, can you just imagine that, that you can go into work and you want to do this dentistry and the occupation that you have in front of you, who doesn’t excite you, you can be like, you know, I’m not so interested. You don’t have to take that treatment plan on whatever. That’s the holy grail man. [James] It is. I love it, my friend. [Jaz] As well as Dentists Who Invest, I was also on the Dental Leaders podcast, one of my favorite dental podcast. And this is with Payman Langroudi & Prav Solanki. And I must play a short and sweet little snippet from the Dental Leaders podcast, which I think you should totally listen to is a great podcast. [snippet] So although I didn’t have enough knowledge to teach, I was always thinking how can I become a better educator? So once I’ve amassed enough knowledge once I’ve had enough failures once I’ve really given it my And I have something valuable to share, then I’ll be ready. So I was I was gearing myself up to it for many years, I was analyzing lecturers, which lecturers really engaged me, excited me the kind of traits they had, which ones although they had all the accolades and letters next name, which one just bored me, I never want to be someone who’s gonna be boring. I always want like engaging. Like, I always paid real attention to Raj Rattan lectures or stories, such an amazing storyteller. That becomes a very important part of me, you know, trying to make it through as an educator. So that was important. And funnily enough, I can go back his first year of dental school, where my buddy Eric, who was a dentist or a dental student from Korea, and he failed his first few exams. And he said to me, “Jaz, if you can help me pass my first few exams, I’ll take it to Korea all expenses paid, right?” So I stayed back within two weeks, I tutored him we got him to pass. But finally let’s bring it back now to this episode, Episode 66, which is on the philosophies of functional occlusion. This is with one of my mentors Riaz Yar I’m so excited to share this with you because Riaz inspired me eight years ago, to follow along this path of questioning about inclusion and including it was actually realized, I think, by pinpointed it, it was him to really set me on my path. He’s such a phenomenal educator. So I know you will love and really resonate with a concept Riaz has to share. The kinds of things we’re talking about today is that canine guidance is overrated. And actually what he suggests is about all about functional occlusion, which is really about the central incisors and first molar is which is going to just blow your mind. I know it is. Before we dive in though, the Protrusive Dental Pearl, how could I forget I would never do this do you, the Protrusive Dental Pearl I have for you is a quote. I want to share a quote with you from John Kois, who I’m sure we all know who listened to this podcast. But if you don’t know who John Kois is, he’s kind of a big deal in dentistry. He is this awesome dentists based in Seattle. They’ve got the Kois center, and the quote I want to leave you with is a beautiful quote. It is “There is no joy in mediocre dentistry.” There is no joy in mediocre dentistry like why do we do what we do? Why do we go the extra mile? Why are you listening to me right now? Right? What Why is this happening? Is because you want to go the extra mile. You don’t want to settle for mediocre? Because this is not fun. Right? When you are not, It’s sort of links back to last episode, we talked about mindfulness. And if when you’re doing your dentistry, if you’re doing back to back class two restorations, for example, and your mind is wandering, it’s not in the room, it’s not present in the room. You’re not giving the patient the best, and you’re not in a state of flow. And you’re not involved in the minutiae of the details, which if we can fall in love with those details, it just adds to our enjoyment and fulfillment as a dentist. So that quote by John Kois, there is no joy in mediocre dentistry. I think that is what it’s all about. That’s why you listen to this podcast because we don’t want to settle for mediocre right? So thanks for listening to my long introduction today. I do apologize. I want to rush right in now with Riaz Yar, one of the best educators I know. Enjoy.

Main Interview:

[Jaz] Riaz Yar, welcome to the Protrusive Dental podcast. How are you my friend?

[Riaz]
I’m fine. Thank you, buddy. I’m great. Just Yeah, thank you for the invite. Excited to do after you’ve had some really great people on here. So thank you for the invite.

[Jaz]
No, absolutely. I mean, you’re someone who really set me on the path for enjoyment of the topic of occlusion. You may not remember this, but it was 2013. And I think our first or second study club was with you in London. And I’ll never forget the first one minute of your lecture. I don’t know if you still do this. You have to tell me if you still do this. But do you remember what you did in the first minute of the lecture?

[Riaz]
No idea. I can’t remember.

[Jaz]
Okay, the first lecture, you just stood up in the middle. Okay, and you played a song, and you just got everyone to listen to a song for 60 seconds? Or there abouts? And then you say you sort of justified it saying that this song reminds you of university and it pumps you up? And it was some heavy metal song. Do you still do that?

[Riaz]
Yeah. I’m planning on it. With [inaudible] [Jaz]
Is it Metallica?

[Riaz]
No, no, no, no, it’s freedom by It’s freedom anyway.

[Jaz]
It’s heavy rock,right? It’s a heavy metal. I remember I had to..

[Riaz]
No, no, it’s actually not rocket fuel. It’s actually it’s very much, I’ll get it here. it’s rare. It was the album was Rage Against the Machine.

[Jaz]
Okay, fine, right. But I remember you playing the song. And I was like, Wow, that’s so unique and so different. So I’ll never forget that lecture for that reason, but also because of the impact you had in that lecture. I mean, that was I believe on the topic of TMD and occlusion at that time, and you made us realize how little we knew the anatomy of the temporomandibular joint that year in a strike fresh out of dental school, and no one was confident in the anatomy and you really brought that home, and then you really play with our minds, whereas you really, you know, made us think hard about occlusion so I never thought forgot you and I’ve been privileged to able to be in some of your lectures. So, it’s a testament to you as an educator. It’s fantastic to have you on for that reason.

[Riaz]
No, thank you. Do you want that you want to listen to rage against the machine again, don’t you think?

[Jaz]
Okay, I’m with you. Okay, fine. Perfect. Is that bond patrol, what’s the song name? Did you get it?

[Riaz]
Radio. Freedom.

[Jaz]
Freedom. Okay, freedom. Okay, there we are then so. So everyone you know, Riaz is sort of a treatment planning song. So that’s playing in the background as you’re treatmemt planning?

[Riaz]
Yes. So basically, that was with dental school. You know, literally, when we left dental school, it was that moment of freedom. You know, we literally were like, okay, shackles of dental school are done. You know, I don’t need to pick up a book again. You know, it was like, literally, I mean, I that’s how I felt I literally was like, I am not touching a book again. Now. It’s just to practice. And you realize very quickly, how little you knew.

[Jaz]
And you know, looking at you, you did a speciality program in prosthodontics. Right? So you did some special training in prosth?

[Riaz]
Yes. So did, I sort of, I was gonna do my maxfacts initially. So my plan was maxfacts, they were not qualified. And I was working as an anatomy demonstrator while I was working in practice as well, that was working in Sheffield doing nothing enough, or maxfacts, that’s it. And then I got married. And then that changed that idea could have like, literally, I’m looking to see if I do Maxfacts. And so therefore, you know, I’ll just do then I’ll just do general dentistry, which is fine. You know what? So bought a practice in 2003. NHS practice. One thing that frustrates my mother the most is, I can’t sit still, you know, literally, you know, I’ll buy a prac. I’ll do something and then I’m bored. And then she like, you just are you get bored so easily. Literally, I think I did it for two or three years, and I was bored or thinking I want to do next. And so what happened was I joined I did Paul Tipton course.

[Jaz]
Okay, cool.

[Riaz]
Yeah, In Paul Tipton. He doesn’t realize it. But he, you know, and this is not actually criticism of it. He made me realize that was not the way I wanted to learn. So I sort of I did is caught on that, you know, I thanked him for it. Because I thanked him for the fact that actually, that wasn’t the way I wanted to do my dentistry anymore. I’ve been learning why it’s not about his work or what he does. It just wasn’t the way I wanted to do. Learn doing courses here. So I wanted a structured pathway. So then I sort of worked my way to get onto a training program. And that was it really.

[Jaz]
And then it didn’t stop because you’re always doing extra things. And recently, I saw something pretty spectacular. You did Professor Zhu Kelly’s, like very coveted, very privileged, soft tissue program. Is that right?

Unknown Speaker
Yeah, masters. I saw the Kelly lecture at the EAD the European Academy of aesthetic dentistry. And he comes on. And just before him, there was a lecturer who talked about bone augmentation. And, you know, beyond all to do with implants. So this little Italian guy comes on, and he’s not tall, but he’s manly, the fiery and he comes on, and he is just like an angry man. Start giving this lecture. And then every sort of every sort of five or 10 minutes, he just stop and go. It’s not about the bone. It’s about the soft tissue volume. And I actually to crack me up, and I just thought that if you I want to learn from and literally his last slide was we decided to run a masters. And I said, so I took the detailed down emails straightaway, they said, you know, nothing’s happening for a till six months after so. But you have to go through quite a stringent sort of process because it’s in belong. Yeah. You want to submit all your qualifications and all these sort of things. And it takes a while. But anyway, I was the only prostho guy on there, because everyone else was, which was good. It was interesting. Because you know, I found the important

[Jaz]
A massive kudos to you. I mean, to me, as you I look up to you so much. And I look at you and I think Wow, man, you don’t have anything else left to learn you can start this soft tissue program that just shows your passion, dedication and your love to dentistry and how passionate you are about it. And definitely, it’s very infectious. But I think that’s what it shows. Right? You’re A) you can’t sit still, like your mother said and B) that you know, your passion and drive is so strong that you want to take on a whole not a completely different field because it’s irrelevant to what we do, but that’s really an admirable thing.

[Riaz]
Yeah, no, thank you. I think I’ve always learned that way. So I prefer to be tested and sort of stretched to learn a topic. And yeah, no, it was brilliant. One of the best thing that I did. It made me realize that probably would never do my training in the UK again, if I had to redo, if I was going back, you know, through my career? Yeah, I would go to Bognor Regis and do my training. No, I go states, I would go abroad and do my training abroad. Because if you’re going to commit to something, I think you should go to the best possible place to to learn. States, Zurich. So obviously, Swiss. You know, I mean, even need to be quite good at the moment. So you know, I wouldn’t do it here. Personally.

[Jaz]
I was very close to actually considering States, myself. And I got the same advice from Jason Smithson, around about four years ago, when I asked him and he said the same, you know, consider doing a Perio-Prostho program in the States or something like that. And a few people say that so, you know, I respect that. And it’s some good information for young dentists listening out there to consider. I do have an episode out there, I think it’s episode three about or two about moving to USA, we follow a young lady who has moved to USA to convert her BDS to a US one, and then you know, the world’s always different from there, so you can check that episode out. But today’s episode is all about functional occlusion. And Riaz, I want to start off by asking you, what do you mean by functional occlusion? And I’m just gonna drag out the question a little bit, because you’re the one who taught me that the role of sort of, the role of teeth is, or the relevant, you know, in general is mastication, in speech and in swallowing, okay? And then now you’re sort of the term functional occlusion. So what, how does that come into it?

[Riaz]
So it is a focus on those three roles. You know, when you think about what you do clinically, you know, you ask your patient to tuck the teeth together, you ask the patient to slide their teeth together. You know why? You know, the question always is, well, why are you doing that, you know, what’s the point of those steps? So when you ask them to tap the two together, that’s the swallowing position, absolute, that’s what’s done. And then when you’re looking at functional movements, you’re looking at mastication movements. So you’ve got to then understand how the mandible works, because that actually, is what teeth are designed to do. And then when you do get that wrong, then problems start to occur.

[Jaz]
Now, straightaway, as I want to start because you taught me that our teeth should only touch together for 17 and half minutes a day. And remember, you’re the one who the first person who taught me that and it was a Graf study in 1964, or 63. And you’re the one who sent me off on that track. And I started looking deep into it. So that my now my thinking is, please get now want to learn from me to correct me if I’m wrong. But now my thinking is those movements that we’re getting to do they are not functional, they are parafunctional. So how do, you probably go into this, but how do you then decide whether it is functional or parafunctional?

[Riaz]
So if it’s parafunctional, you’ll see signs those parafunctional. The functional movements, I think, you know, when I said that 70 and a half minutes, the follow on point from that was, what does that tell you about teeth? Well, that tells you that teeth are only really designed to touch for that length of time. Now, let’s even elongated say let’s say 20 minutes or 25 minutes, because that’s really, you know, that’s only one study that looked at in depth. So then when you look at that, you will find that but then parafunction is simply the extension of that. So function, low forces, less time. Parafunction, more forces, more time. So when you have those factors, we know teeth aren’t designed to handle that. So then you’re going to get problems with the teeth, it’s either going to be fracture, we’re mobility, migration, mastic, muscle issues if they’re parafunctioning, TMJ issues, you know, that they’re all the factors, sleep issues, you know, if you look at sleep apnea and parafunction, postural issues depending on try centric relation, if that’s, you know, philosophy you want to expand into. So the impact of teeth isn’t just this small little box that were designed to teach, it’s far greater on the overall health. So when you look at functional occlusion, we have to look at also what the impact is of functional occlusion because if you break your food down properly, you then digest your food better, your health is better, your sleep is better. If you are doing the thing that the teeth are designed to do which is related to the mouth is isolated to the overall health of the patient.

[Jaz]
How can you make that clinically applicable? I mean, is it just the same stuff we were taught at dental school well You know, that two hour lecture that we had on occlusion at dental school where, you know, we have our definitions, which are confusing enough. And then obviously, you want to try and get the concepts of anterior guidance or the minimal stress dentition. Is there anything that when you’re talking about function occlusion, is there anything that you think was was skipped or missed at dental school that you’d like to some key points I’d like to bring home during our short chat now.

[Riaz]
I think it’s teaching philosophies on occlusion is the biggest problem because we’re taught canine guidance, for example. So you know, you’re taught canine guidance at dental school and you’re told that that is physiologically correct occlusion. So when someone moves the jaw to the right, and the canines, take the guidance, and disclude, the posteriors, that is actually functionally and physiologically correct. And you have to then go back a step and you say, okay, you want to deliver canine guidance for your patients when you restore them? Why? Why would you do that? Number 1. Number 2, Who told you that? And what is it based upon? Because it’s like building a house, if you’re going to build the foundations on that house? If you’re using canine guidance as your house, what are the actual underlying pillars that support canine guidance? So if you then read D’Amico’s work, he published it in 1958. And then the other subsequent papers in 1962. And he said, you know, his rationale behind canine guidance was to refute the balanced articulation scope, which was what that was going on at that time. You know, everyone was given complete dental occlusion when they were rehabilitating the patients, and then there was numerous issues with it. So he said, No, that’s not true. It should be canine guidance. And he looked at Dr. Gregory’s work, Hector Jones work. Dr. Gregory he was the one who did his studies on Aborigines and they showed the wear of the canines. So it was like, Yes, you’ve lost a canine survival? No. First his. His understanding of the anthropological data was not quite right, because he only looked at certain number and not looked at a greater range. And canines are important teeth when it comes to function, but it’s not the establishing tooth of functional occlusion. The two teeth that established functional occlusion are your central incisors and your first molars. So if you think about it, then you go, Okay, well, why is that the case? Well, the reason that’s the case is they’re the two teeth that erupt first. So if you look at biology, and physiology tells you what which teeth are the most important teeth when it comes to function? It’s the incisors, and your first molars, you don’t see hypodontia first molars or central incisors are often, you do see a lot of palatally impacted canines. So if a function is designed, is dictated by the canine, then the poor child is not chewing properly from the age of six to 13. So functional occlusion is based around the principles of your first molar and your central incisor. And canines. .`

[Jaz]
That’s really facinating.

[Riaz]
Yeah, because canine guidance is part of your functional guidance, but when you go to canine guidance, you go beyond the envelope of function. So then what is the envelope of function while the envelope function is a three millimeter lateral movement in which you break your food down, you go beyond three millimeters, that’s then parafunction, that’s a habit based movement, not a functional movement. And that’s when you get wear of canines. And I used to always make me laugh when someone said, you know, when worn canines, give them canine guidance, because it switches the muscles off. No, you worn the canines, you’re going to worn when there’s a composite, you’re going to wear the [inaudible] [Jaz]
It will happen again.

[Riaz]
It will happen again,because it’s not the canine guidance, you actually want group function in those patients because you want to share the loads and amongst all the restorations. So especially oblique because you know, materials are very good at compressive loads, swallowing loads, but not great at lateral oblique loads.

[Jaz]
One thing I just want to oppose the the areas and talk about a common error I see or people talk about is sometimes people message me and say for advice, they say hey, I’ve got this patient and they’ve lost canine guidance, and I’m thinking of adding some canine rises. But what’s happening is that they’re choosing these cases whereby if they add these canine rises, then as soon as the patient then goes into excursive again, there’s so much tensile load on that composite. It’s just going to break off and there’s no surprise when it fails. And you mention the great point which I want to highlight, because otherwise in passing, you could miss it is about those oblique. So in those cases, would you agree that perhaps if you were going to go down that path, you may then and there’s gonna be the rest of podcast, which is about raising the OVD but yeah, to me, you may have to consider raising the OVD or some orthodontics to be able to turn that load into compressive load. Am I going along the right path, you think?

[Riaz]
Yeah, OVD increases based on overbite and overjet. So your decision for OVD should always be analyzed as part of an overjet-overbite analysis. And I think that’s where the biggest problem is, because people think, yeah, I need the OVD to create space for the restorations. That is true. But when you increase the OVD, you reduce your overbite, so if you will reduce the overbite, you need to then make sure that you’re posterior disclude, the anterior certainly, but the incisors disclude the posterior. So if you then get the curve, then you have to make the curve of Spee flatter. If you reduce the overbite, so these are all things that we don’t realize we’re doing when we think about OVD, everyone just increase OVD. It’s easy as that. But when you increase the OVD, think of it like a clock. So you are at nine o’clock. And if you increase the OVD, meaning you go from nine to six, what happens to the line, the curve, you go from nine to six, you increase OVD but you also increase the overjet. That means you got to put material somewhere, it’s going to be either on the palatal aspect of the uppers and the labial aspect of the lower incisors. So yes, OVD is an option to give you bulk of material and change the angles and give but it still won’t protect against oblique forces, because of materials in bulk are still great with compressive. But oblique forces, they’re not great.

[Jaz]
But by oblique you also is it aka tensile stress, Is that good? Yeah. Okay, fine.

[Riaz]
Oblique means tension. So you basically put more tension on the restorations, therefore, they’re more likely to fracture or if they’re stronger than the underlying core, then the core will break. You know, that’s sort of the, it’s a balance. Someone has to win when it comes to force. So yeah, I think with OVD you increase to give you more material. So you bond onto depth of enamel. That’s the ideal. So you’re going, I’m gonna increase because I can bond to enamel therefore greater bonding strength, greater management of forces. But you it’s, the key decision factor is your overbite, overjet and your smile, because when you increase the OVD, they have the overbite is reduced, then you need to increase the length of the upper incisors so the patient shows more teeth. But if they’re already showing the right amount of tooth you’ve got and then take the gum. So, this is you know, OVD, you know, I give an advanced, two day advanced course on sort of looking at in detail OVD and how you analyze because the problem you have with occlusion is you use an articulator, that’s the problem. So it’s sort of whatever the reason why we do canine guidance, and we can’t do functional occlusion, is because the lateral movements on an articulator are nothing like lateral movements on the human. And the reason for that is if you just even go back to the basics of the articulator, if you just look at the ball and and joint of the articulator, first the ball is circular, and the fossa is Angular. When you look at a CBCT of your condyles they look like potatoes. They don’t look like balls. The glenoid fossa is not a perfect rectangle. So it you know, you can buy foster inserts, but you know the anatomy of the TMJ joint is variable.

[Jaz]
Riaz, you just reminded me of Episode 31 I did with someone called Dr. Andy Toy. I don’t know if you’ve come across the PGO, the posterior guided occlusion theory?

[Riaz]
Posterior guided occlusion theory meaning using the molars to guide the occlusion in?

[Jaz]
Yes, but also there’s an equation that Andy Toy and his team Ronald Presswood found whereby they did some anthropological studies and they found that Zola’s typical and the glenoid fossa and the angle that produces just like you said, that you know, the reason that can’t be produced into an articulator because too complex, but they found thatangle is the same angle as where the molars are at. So that was an interesting two episodes about how canine guidances is not The end goal shouldn’t be. And really, he talks about the PGO model. And if you haven’t checked out because I’d love to send you that to check out because I know you love this sort of stuff. But just wondering if you come across Andy Toy before and the posterior guided occlusion?

[Riaz]
I’ve heard of the theory, I’ve not heard of that terminology. I mean, we call it functional occlusion, because the dictating tooth is the first molar. So getting that, you know, distal buccal cusp of the upper molar, for example, right, and getting the curve of Spee right and getting your curve of Wilson right means you can design functionally indirect restorations, because one of the biggest challenges I think Dentists have are rebuilding first molar, because it’s the first two that is exposed, and therefore the first two that decays and first target needs endo and first, and it’s always that first tooth that needs the most work. And then, you know, most commonly people talk to me about, you know, the onlay looks really flat and don’t have the right shape. I don’t know if you’ve seen what we’ve done, do you know Nick Sethi?

[Jaz]
Yes, I know Nick very well, and I’ve seen some of the stuff you’ve done and the, I mean, do you want to talk about FIPO? Or is that for another time or?

[Riaz]
Absolutely another time. I think it just that was sort of the whole idea behind FIPo was that we do. We do a lot of our restorations, but we’re not looking at the true morphology and shape of teeth. And to try and design functionally driven restorations simply, you know, with a simple protocol, is what people really struggle with. And so we’ve been, that’s what the FIPO protocol is. But that’s just one of the principles that leads into, you know, you get the first molar, right, everything else is pretty straightforward. Once you have like guidance of the six, and then the five before the three cuspal inclination, and that’s what I thought modjaw helped. It’s helped me analyze more what I’m doing and, you know, see whether we are, you know, ultimately rehabilitating the patient, not just restoring them.

[Jaz]
Riaz, for those listeners who haven’t heard of modjaw, because younger does listen to this, and they may not have come across modjaw, I love your sort of postings that you do in your videos of showing people’s chewing patterns and whatnot. But can you just explain to those who haven’t had a modjaw before what it is and why it’s so awesome?

[Riaz]
So we’ll look at, this is the first, was not the first time not strictly true, but it’s probably the best technology we’ve had to date, where we actually use the human as the articulator. And how it works is it uses similar sensors that Pixar and animation use, you know, to replicate human movements in their cartoons. This is what we’re doing with that. So this is using a camera, infrared technology and using sensors on the patient. And what this is doing now is we’re actually looking at the data of the patient as the true articulator. And so this is using what’s called 4D technology. So we’ve gone from 2D 3D, we’re now into 4D, and it’s pretty amazing.

[Jaz]
And the data that gives you is just amazing. And it helps you to be a more functional dentist, I guess it actually can, you know, given the patient the best function. But the questions that are in my mind now is how can you make this actually tangible in terms? I mean, it’s very difficult, such a broad topic, but most people have been throughout dental school and they come out thinking that yes, canine guidance is what it’s all about. And it makes sense some degree is further away from the TMJ hinge. I remember you taught me the importance of canine guidance for those reasons, but also, mostly due to restorative convenience. And how easy is for technicians to build that in whatnot? But what are you saying now? You saying that you want the sixes to have some guidance? Can you just make it more tangible? The point about functional occlusion how it relates to sixes and ones and what is it that you’re actually looking for in terms of the dots in mind?

[Riaz]
So what you’re looking for is what are called your trajectory movements or your functional guidance. And so we call this cycle in and cycle out. So what that means is when the patient is coming in to the teeth to touch, that’s called cycle in, and that would be guided off the palatal inclines of the upper buccal cusps against the lower buccal cusps, the lower supporting cusps, so that’s what is guided in. Now the guiding in is what is the data for the brain, but it’s the guiding out there’s what’s called the cycle out, which is now the actual guidance against the palatal cusp of the upper is what breaks the food down. So this movements, and it looks like a pear, the classic description is a pear drop, and it’s not. I don’t think it’s sick strictly like that. It is certainly what I’m seeing Data Wise, is that we are getting a certain you know All shape. Now, what we’re looking at is two movements. We’re looking at the opening movement, and then the lateral movement, and then the closing movement in it. Now what I’m doing at the moment is I’m looking at patients before I restore them provisional restorations, and then my definitive restoration. So I’m looking at the chewing movements in three stages. And I’m answering the question whether I’m making things worse or better. Now, patients don’t recognize the restriction and cheering because they adapt. And if a patient has good adaptive capacity, they will say nothing to you, they’ll come in with your beautiful restorations and will tell you everything is okay. And that is right in their mind. Because functionally, they have adapted to what you’ve given them. But if you were to actually look at the chewing motion data, because remember, teeth are designed to break food down, you would probably find that the chewing cycle has narrowed and become more vertical, meaning that they’re still chewing but the lateral component to protect themselves from breaking your work, or because of the design of the teeth, that they’ve got themselves. So the movements of guarded, the functional movement is narrowed. And I can show you a picture of a case which we did. And when I did the pre treatment, I know people won’t see this book, I think it helps to sort of if those that do see it, then it consult

[Jaz]
Those who watch it on Facebook, Instagram, and YouTube and whatnot. So we can almost describe it. But what that mean, as you’re loading it up, and as you’re about to share your screen, I believe there is a Landin and Gibbs study whereby they had people in this or, you know, let’s call them cows, you know, like side chewers, for example. And then, after rehabilitation, they became vertical chewers. And I believe that was seen as a good thing. Are you suggesting that’s not a good thing?

[Riaz]
Yeah, definitely not. I think if you look at this sort of case here that we did, I mean, this is sort of, this is the starting position of the case. So just to give you an idea of where she was at, that’s the starting position. She’s got a bridge from the upper right, four to the upper right six, and the false failed, the three is in the position of the two. So that’s actually a three, canine and if you look at the sort of the design of the teeth before, just look at the shape of those cuspal inclinations they’re very flat. Yeah, that’s because we use an articulator. Okay, so that’s, that’s a type of design, depending on whether your average value set. So that’s just a modjaw. So what I did was, I did a preposition. So if you look, if you actually analyze the data on this, you’ll see that the width of the position is four millimeters width at the bottom. Okay? So each square is one millimeter.

[Jaz]
Okay.

[Riaz]
Okay? So if you look at the arrow four squares, so her width of lateral movement is four millimeters. If you look at what I did, and I put it into a provisional first, and her width increased on chewing on the right to seven millimeters, and then in a final, her width moved to round 10 millimeters. Now this is the bottom. So that’s actually when she opens the mouth laterally. So what does that tell us? Does that tell us now that her muscles are more relaxed? Does that tell us that actually, she’s more comfortable moving. But the next slide is what really sort of hits home this, because if you look at the cycle in, now the foot, the vertical movement when they’re coming into the teeth touching, okay, that’s where those lines also, this is now where teeth are touching. So when she started, she was two millimeter lateral movement when she comes into chewing her food, though. So the red is cycle in, green is cycle out. But look what happened in the provisionals. She actually had the same two millimeter width, but can you see the trajectory? It became steeper. So why was that? That was potentially her way of guarding she was going, actually I know my bridge is provisional. So I when I chew, I narrow my chewing cycle. So actually, don’t put too much force on an oblique angle. And then look what happened when we put her into a final? Look at the width and the trajectory totally changed. So she’s gone from a two millimeter functional movement and that’s because I’ve corrected the angles. If you look at the sort of the shape of the teeth, but that’s sort of, that’s where she’s at now. But if you look at the shape of the teeth on the right, Look at the way they’re positioned to be totally, you know, functional. And so, hey chewing has improved, you know that that is our role, our role is to improve the situation, improve the functionality.

[Jaz]
That’s very fascinating. Absolutely.

[Riaz]
if you look at this sort of cases where I mean this is, these are the angles of the cusps on a modjaw, you know, this is what functional teeth should look like, you know, they should have steeper angles, steeper. And that’s because teeth are designed to break down, your morphology is actually like this, you know, whereas, when I look at what we used to do this is before I had modjaw, so, these are cases that I did before modjaw if you look at this case, here, you know before..

[Jaz]
On the right side is what you would do before modjaw?

[Riaz]
Now these are both modjaw left and right but if you looked at the next this case here what I did without, this is what I used to do look at the this is on another bridge value articulator you know, look, if you look at what I did, I also I did this with a case, I did a case where I made two sets of restorations on the posterior. So I did you know, if you look at that, if you look at the cuspal angles on the average value, and what I did here was I sent it to two different labs in two different countries. So the right modjaw is done in France. On the left side, the average value is done in the UK, or using my digital scan data, but one was done using motion data. And one was done using average value settings on the digital articulator. So look at the cusapal inclinations of functional data. Can you see how the palatal inclines and the buccal incline is the same when you have functional data. But when you don’t have functional data, look at the different angles. It’s sort of, you know, different shapes, there’s no force to functionality. Whereas when you do restorations or a functional look at the similarity in the shapes that are created, you know, this is a bridge. So this right one was made on modjaw, the left one was made from average values. These are all cycle in angulations, if you use an average value, the cycle in angulations are all obscure. But if you use motion data, you have very similar cycle in pathways, because that’s all teeth, designed to be functional and break in if you don’t.

[Jaz]
Riaz, I’m smiling, because you’re doing it again, you’re doing that thing they did to me in 2013, you’re making me think, you make me like rethink everything.

[Riaz]
You know, I thought, you know, when the penny dropped, gone, it was like an epiphany moment. And literally, it took me, It probably took me six months have to stop kicking myself, because for six months after the penny dropped, and the jigsaw everything just fit it together, I thought I was kicking myself solid, because six months, even now when I think about it, I get irritated with myself, because why I got irritated with myself is because I blindly believed what I was taught. And I never questioned it. And I should have questioned it from the very outset, you know, and someone’s had canine guidance to me, you know, and they gave me the rationale, I should have still gone Why, why why? or Why? Why? Why you know, and, you know, I want to use this opportunity to thank my mentor, because, for me, the guy who really planted the seed on functional occlusion was a French guy called [?]. And he passed away on the second of July. Very dear to me. And so, you know, it’s credit to him. But he sort of, you know, literally blew my mind, literally shattered everything that I read up until that date, and just, you know, made me think, you know, Ever since then, you know, I was like canine guidance, why? It’s crazy to even think that one tooth is gonna function and guide you. And it’s just, it doesn’t even make sense. Now that I say.

[Jaz]
I spot on I agree with you. And I definitely see the world and again, my world has been shaped by you as well in the past. So I definitely agree with you that canine guidance is not the be all and end all and most of our patients in the natural dentition don’t have it to begin with it. Would you agree with that statement?

[Riaz]
No, I think they have canine guidance. But if beyond and beyond the natural movement is the I have canine guidance on my right. But I have to go to an excursive movement that is not functional. It is a parafunctional movement or it’s a habit based movement. So when you do canine guidance, you don’t chew like that. You don’t have to have your canine to guide you in.

[Jaz]
Okay, brilliant. So yeah, I mean, one thing again, I’ll reference back to the the PGO episode is that one of the theories cuz now we’re just getting to philosophies and theories, which is quite interesting actually, is that if you were to observe canine guidance and you know we do this all the time your patients supine, Okay Mr. Smith can please grind your right half time they know what they’re doing, but when they do figure it out, you can see Ah, yes, the canines are touching and the posteriors are discluding. And you may say, okay, that’s canine guidance. But when you actually get them to do it with some force, you’ll suddenly see all the back teeth involved in that guidance movement as well. So the theories suggest that actually, how many people are really on canine guidance at full force, which is really what you’re doing in a parafunctional movement, or perhaps nocturnally. And what the PGO model suggests that actually, very few people are in canine guidance, because when you actually do the healthy clench, when you actually put some force into it, you compress the PDL, and you sit your condyle perhaps a little bit, and then suddenly, the sevens and the sixes and the premolar is coming. Oh, I’d love to hear your view, or the take on that.

[Riaz]
You know, forces in functional movement are low, unless your food is hard. So functional forces are low, you know, if you use [inaudible] paper, you know, you’re looking at 40 Newtons, which is 80 Snickers bars, you know, so the force of 80 Snickers bars the weight of 80 Snickers bars, it’s not actually that heavy. So you know, and that’s, if you’re gonna chew something a bit hard, you know, someone needs a bit more force. That’s why the incisors are so important, because of the number of periodontal mechanical receptors in the anterior teeth are more than the posterior teeth, because you grab the food, and that data to the brain tells you how much force you need to apply on your posterior teeth. It’s why you know, not to chew soup. No, you don’t think about it, you just you just put in your mouth, you know, it’s liquid, you don’t chew it, you swallow it. And if you have a bit of crouton in it, you know, straight away whether there’s a bit it’s hard crouton or soft, so this data is part of functional data. So functional forces are low, when they talk about clenching forces. And other Yes, you, when you apply force, you increase elevator muscle activity. And so the rest, the rationale behind canine guidance was because canine guidance separated the posterior tooth, and therefore switched off elevated muscle activity. But for functional occlusion, you want muscular elevator activity. You want it because you’re breaking your food down. You don’t want to be switching off your muscles, because..

[Jaz]
That’s what they are. That’s what the PGO camp argues as well, actually one of the muscles on you don’t want them off, which is, which is in agreement with you. Absolutely. But I mean, there’s so many directions we can go in this episode. But really, this is an introduction for us to functional occlusion. One thing to ask to make it tangible is can we make functionally correct restorations without modjaw? That’s question A and the B part of that is, can we just achieve that if we’re conforming, by following the cuspal inclines of the adjacent teeth? Would that do the good job?

[Riaz]
Yes, if the adjacent teeth, looking at the mouth, is going to help make a lot of your decisions for you. So for example, using the FIPO protocol, for example, like a lower six you’re restoring, but the upper six is a natural tooth, it’s fine. So what I do is I just basically a bit of self etch primer on the tooth, and I put a small bit of composite on them and I get the patient to bite into that composite and light cure it. When they open. you then have the cuspal inclines of the palatal cusp in there, that is your data, you can adjust it a little bit to get the right inclination, but there straight away you have your anatomy of your restoration. So you don’t need modjaw to do functional restorations, you can do it quite quickly with a bit of self etch primer on a small amount of composite nuts if you’re doing single or two or three restorations. When you start to do a quadrant of dentistry, then you need to look at obviously functionally guided pathway techniques. So for example jaw, asking the patient to chew but not getting them to grind the teeth, but actually getting them to chew and get the data the other way around. You can then do it without modjaw but then the technician will struggle because he’s then putting the data on an articulator. So, the challenge is not you we can do it ourselves. But the challenge is when you then give it to the laboratory. Now if you’ve got digital you can potentially scan that and then they can use a digital software to then design the restorations using those inclinations. But even on digital, they using digital articulators set average value settings because with digital articulators you’re not populating it with a protrusive bite. You’re not populating it with [ ? ] function, for example, or [3D occlusion brand] or other devices, DNR cardiacs these are the digital tools that give you values to populate an articulator. So the modjaw, you know, it’s for me, because I got a lot of questions that I need to answer. And some of the questions I’m starting to answer in my own head, you know, am I rehabilitating the patient? Am I making their function better? And, you know, part of that assessment is obviously a muscle assessment, the TMJ assessment. And, and I think, to be able to do good quality dentistry, you don’t need expensive tools, you have to just first be able to understand the basics, well, that’s a good start. And then you realize that the tools will make you a better, will make you understand more and therefore perform better. And then, you know, you will end up investing because you invest in your career. And I think our modjaw, I think modjaw will be, I think that is potentially going to be one of the most essential tools we’re going to have if you’re doing rehabilitative dentistry in doing multiple. But if you’re doing general single arch, single tooth dentistry, then clearly no, you don’t need to even multiple units here in there. You could design the teeth, just looking at the morphology of the opposing arch and correcting it with composite, that’s well.

[Jaz]
Brilliant. I’m just very mindful of time, I’m going to throw some quickfire questions at the you Riaz, because it’s taking a very interesting, I’ve really enjoyed your almost philosophical debate. And there’s been some parallels to the PGO concept, which I’m definitely send your way because I’d love to have your input on that. But the kind of question that have now based on everything you said, is Frank spear said, in his sort of treatment plan sort of thing he EFSB. So aesthetics, function, structural, biology, that sort of famous sort of treatment planning sort of acronyms you like. And then and then Michael Melkers has always taught me that, in fact, it aesthetics, parafunction, structure, biology, because when we’re doing a rehab, and this is what the the canine guidance camp will tell you is that when you’re doing a rehab, you want to set the patient up for, to reduce the the forces in every way possible. And that’s what you sort of alluded to, as well that you know, it reduces elevated muscle activity. And of course, you want to get onto the anteriors as much as possible, whereas now you’re saying the Sixers have an important role. So now that you’re doing your rehab in a functional occlusion way, and you’re checking the occlusion at the end to make sure it’s set up for success, what percentage of the rehabs now have got pure traditional canine guidance? And what percentage have group function? Is that a fair question just to get an idea of what the end product actually looks like?

[Riaz]
Yeah, so I think in the last, since I bought the modjaw, everything has been shifting over to quick function. And prior to 18 months, it was, I was using FGS functionally generated pathways to try and get good function. But it was more difficult to do it was easy to just give them canine guidance. Because patients adapt. So I think, to date now, pretty much every case is a group function, it’s parafunction. Now I know, you know, what Michael said was, you know, aesthetics, parafunction, you want function first. And for me, if you get functio right, function and parafunction are not too different in their movements. You will have some that do more obscure movements, but you can’t prepare your restorations for that, you know, when they have a true habit based occlusion, you can’t prepare, you’re designed to protect against that. If they got, for example, they’re moving their jaw to get to that lateral incisor, or that canine, that’s a habit, you know, you they will just destroy that area, and you’re just going to be rehabilitating that area, you can’t switch off the parafunctional habits because parafunctional habits aren’t truly occlusion based. They are much more than that. They’re genetics, they’re hormones, you know, Hashimoto patients, Chlamydia patients, you know, you can have so far greater link to parafunction than just teeth. But that’s not to. I’m not, you know, I listened to Manfredini. I’m not that solid to the point where occlusion is zero? I think small, I think it’s a small amount in certain patients, but it’s definitely not all of it, you know, it’s not like occlusion. And then it’s that right?

[Jaz]
Absolutely. And you’re the one who taught me about micro trauma and macro trauma as I look to you in terms of my learnings with that. And just to wrap up a few more questions that I have I had a really good one. Now that you’re finishing these cases in group function, and perhaps the reason these patients ended up in your chairs, especially this is because they have done weird and wonderful things for dentition. There have been parafunction, they have been bruxing, they’ve worn their teeth away. And now you’re building the functional occlusion which involves group function. A) you’re not worried that they’re going to destroy with increased elevated muscle activity, all the lovely restorations that you put in? And B) does every rehab get a appliance for protection?

[Riaz]
If the underlying cause is also is parafunctional, then yes, for nighttime where they will get a protection or get there because that is something that we can’t control. So they do get a splint, if they’ve spent that sort of money. How, will they break my restorations? We’ll have to do the podcast in a couple of years time? And I’ll tell you, because at the moment they’re not.

[Jaz]
Yeah, of course.

[Riaz]
You may be absolutely right. In in two years time I, and I’ll be opening up, you know, I’ve learned this, you know, with people that have been through with me through my journey of will have seen me change my understanding and my teaching to reflect what I’m learning, and why I’m changing and why. And just to find it. [Kelly] was the one that taught me that with, you know, absolute passion, that his position five years ago is different to his position now. But that’s because what he’s learned and what he’s doing. So I’m, you know, recording these data’s and I’m doing the modjaw and I want to know, you know, do our patients I mean, that bridge may only last two years. Is that because of what I’ve done? Potentially. Could it be that she bit on something hard or, you know, a fellow but you know, it’s all these unknowns that we don’t have, but certainly, you know, we’ve got to be reflective critical of ourselves, when we’re looking at our work. So yes, I may come back to you in two, three years time ago. And story, Jaz, whatever told you in that. But I’m actually more comfortable in my skin now about occlusion than I’ve ever been. And that I’m now more solid on that. Now I’m happy to stand in front of thousand of people. And before, I believe I understood it, but I never really had 100% conviction, there was always this niggling doubt in my head. And I just couldn’t get it out of my head. It took, you know, years and years of reading and reading and reading. I just, it just never comfortably sat in my head. And so there was always this niggling doubt. And it always hit me when someone asked me a question, you know, and the biggest question that always got me. If the canine tips, Why would you give them canine on guidance again? I was always stumped by that question. Please deal with the material away rather than the tooth? That was my answer. And I remember even sort of saying it always felt I didn’t say hypocritical, but it just never felt, you know, yes, I did it. I was taught Robin Gray was one of my mentors who was you know, fantastic TMD, fantastic dentist. Steven Davis, one of my mentors, an amazing guy. And very knowledgeable. But I just have time with me. Until now. Now I’m comfortable in my skin.

[Jaz]
That is amazing. And I think that wraps it up, Riaz. Tell me, where can we learn more about your way of thinking now? Because there’s a lot of people who can have lots of questions in their head. And so I know you’ve always been a good educator, you’ve had your year long programs in the past, then if you start doing that, but where’s the for the hungry minds that we have. Which reminds me that I mean, we’re study club as well, where you people come and you feed them? That was great, by the way. Tell us where can we learn more, Riaz?

[Riaz]
Yeah, there will be some data coming out with our recent restriction of we were running a two day course in November, that is, again, tentative now I don’t know if that will happen. So I think just wait till next year, the year long course is starting again in February. It’s with, it’s going to be a diploma in Advanced Aesthetics. So that’s starting in February. It’s going to be me, Nick, and Sanjay, who are sort of running that program. So I think..

[Jaz]
Is that London or?

[Riaz]
Yes, it will be in London and in up north. So Manchester and London.

[Jaz]
Brilliant, please do send me a website link. So I can stick that on for those who are interested. Because part of it is that I bring on lots of educators of various backgrounds, and some listeners will resonate more with just that, you know, some will resonate more with certain educators and other educators. So I want to give everyone the platform and it’d be great to have that. So check it out guys. Riaz has has blown me away once again and reset that sort of hunger to learn. So, thank you so much for giving up your time and Maybe I will take you up on that part two, because, honestly, I’m looking through my questions that I had. And we didn’t even get to when to just conform and and reorganize the staff, because it just went a little bit philosophical. And I really enjoy it for that reason, but one day what we might cover that.

[Riaz]
Definitely, my pleasure. Thank you, Jaz. And well done, by the way, I love what you’re doing. And this is, you know, it’s brilliant. And kudos to you. Because I think, you know, what you’re doing is giving everyone that opportunity to learn, you benefit, but actually you’re sharing it with everyone. So yeah well done.

[Jaz]
That’s very kind of you. Thanks so much for your inspiration we appreciate.

Jaz’s Outro: Thank you so much for listening as always, all the way to the end. I really appreciate it always. Hoped you enjoyed and gained value from Riaz. I think what he’s done to advance studies in occlusion and helping us dentist understand over the years is just amazing and phenomenal. It’s one of the reasons that why on the splint course, one of the first few slides are having a splint course there’s a photo of him, as well as many other dentists who inspired me to learn more about occlusion and made me better at delivering splints, and maybe question the why, the how, the when of splints. So Riaz is definitely in that category of these inspiring dentists. That meant a lot to me in my journey. I’ll catch you in April which is straightpril, and we’re going to talk all about orthodontics over the next month. I hope you enjoy. Reach out to me on @protrusivedental and it’d be great to connect with you all. Enjoy Straightpril!

Hosted by
Jaz Gulati

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Episode 83