A Short Discussion on Occlusion Part 1

Are you confused about Occlusion ? Not sure about when to take a record in MIP or CR ? Or maybe you are unsure about the correct type of Splint to use, and when it is clinically indicated ?

In this companion podcast, recorded after the Understanding Occlusion program in Mackay, Dr Michael Mandikos answers some of the questions that were raised at the course, and he provides some insights into Occlusion and Splints, for those who were not present on the day.

To access the full recording of the Occlusion Course, subscribe to Correct Dentistry. Our Foundation Membership is just $99 per month and gives you access to hours of high-quality educational content presented by specialist Prosthodontist Dr Michael Mandikos.

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This podcast is brought to you by CORRECT DENTISTRY

Transcript

SPEAKER_02 0:08

Welcome to the Correct Dentistry Podcast. And this morning I'm joined by Dr. Michael Mandikos, and we're going to be discussing all things occlusion. This is actually a companion podcast to our program that we ran in Mackay last weekend, which was a really wonderful program. I got a lot out of it. And I know that all of the people that came along, we had a full room, a really engaged audience. And I observed them from the back of the room, and I really felt like they were really absorbing the topic in a really big way, which is probably unusual when you're talking about occlusion. So, Michael, I think that one of your great strengths is explaining these topics that are really challenging in some really easy to digest ways. But we are talking about a really challenging topic. You spent a long time at the start of the program discussing all the definitions that have changed over the years and why, why this is such a challenging topic. Can you go into, for the people that weren't in Mackay, why is occlusion so tricky? Why don't we understand it? What are we getting? What are we missing?

SPEAKER_00 1:17

Yeah, I think it's, thank you, Jill. It's um it's a great question because if you think about what we do in practice every day, you know, every day you're drilling on some teeth and restoring them. And those teeth have to meet the opposing teeth. So you're doing something to the occlusion. In this case, you might be conforming. Sometimes you remove teeth, or if you're an orthodontist, or you do some orthodontists, you're moving teeth. All these things involve potentially altering the occlusion. And if you're altering the occlusion, you need to know something about it. And yet somehow we mostly get by. Sometimes we get by with a lot of adjustment. Sometimes we get by and things seem to just meet, you know, the teeth just seem to come together. It's it's just dumb luck. But the reality is, I mean, dentists need a really good understanding of occlusion. And the irony is, is that, you know, as we said at the beginning of that lecture, you know, put your hand up if you feel like you've got a good understanding of occlusion. And most people didn't. And I think really that first few minutes that you're talking, well, probably it was more than 15, 20 minutes, um, that you were talking about was about trying to engage with that audience and and validate their reason for coming along, because there were many younger dentists there, but there are also some older dentists too. And you you you sort of didn't want people to feel like you've come along because you're an occlusal dummy and you you're embarrassed about it. I was really trying to let them know why it's not their fault that they don't understand occlusion.

SPEAKER_02 2:44

Yeah. And so for you, obviously you've finished your undergrad and then went on and studied a specialty program in PROZ, and you've been in private practice for a good while. When do you feel like occlusion really clicked for you? Was that when you were training, or was that when you were in practice and you were starting to do more challenging full mouth cases and you saw some failures? Was it was it failures that taught you these things? Or how did you get to really understanding it so deeply?

SPEAKER_00 3:16

I think you're right. It's um I I I'd like to say I had an understanding of occlusion when I left dental school, but I didn't. And that was really what I was trying to communicate to the audience, too, as a starting point. You know, we're all on the same plane. And then when I went and did my pros, you know, I know that they taught us a lot about occlusion. And, you know, and we had some some nathologically trained people in the program. We had a great professor, Norm Mole, who was in the oral diagnostic science area of occlusion and, you know, widely published. And they taught us a lot. And and to be fair, I I think I I learned about it, but it it probably wasn't practical until I actually started to practice. And in my mind, I actually have uh a fairly spectacular failure of uh, I think seven anterior units in a in a class two div2 bite that I can recall in the first couple of years of my practice. Um, you know, I treated that person with hindsight a bit, a bit blinkered with with without maybe blinkered's not the right term, maybe more like an ostrich with my head in the sand. I I, you know, I really feel like the stuff I'd learned I hadn't assimilated well. And it started to gel when that man's case came apart. Um so yeah, I think in answering the question, it it it the education was there, but I had to see it practically to really understand it. And that's really the basis, I think, for being somewhat passionate about trying to teach this topic to make sure that people get the theory but but as much as possible get it practically.

SPEAKER_02 4:44

Yeah. You did also spend a fair bit of time talking about dentures as it relates to occlusion and how a lot of the concepts that we understand have have come about because of dent denture dentistry. Um we're in an era where we're doing less dentures now. Do you feel like we're skipping ahead, we're not understanding things, and we're moving into complicated, fixed protocols when we don't have this deep denture-based understanding of occlusion? Um or do you think that matters?

SPEAKER_00 5:17

Yeah, so you you you you have a knack of asking great questions. And they to my mind, they have a few parts. I think first of all, you know, we we could one day sit down and do a podcast on dentures, um, which isn't going to sound appealing to people, but but I think as we discuss it, it would make more sense. There's a lot that we give up when we stop doing complete dentures. I mean, a denture is a com is a full mouth rehabilitation. And anyway, but but that aside, what we were discussing in the program was was denture occlusion. And denture occlusion was the beginning of occlusal schemes, concepts, because the original dentistry was really replacing everybody's teeth with removable prostheses. So they needed to develop concepts that would help give stability and retention to these prostheses. And that's that's where the balanced occlusal scheme came from. So now bringing that back to your question, um, we're doing less of that and we're seeing more complicated fixed dentition cases. Part of the problem with the way occlusion's been taught is that occlusion evolved from concepts for complete dentures into concepts to be applied to dentate patients, and they're different patients, and they require different occlusal schemes. Yes. But there was a carryover to start with, and some people still believe that carryover is necessary and exists and and and needs to be built into their cases, and some don't, and then you you start, you know, the occlusion wars people with different opinions.

SPEAKER_02 6:45

I suppose another question related to dentures that that comes to mind is we're talking about the occlusion once a denture has been fitted and how that relates to a fixed case. How about the mechanisms and the protocols for how you register centric relation in a denture patient as that compares to a dentate patient? Do you feel like there's skills that you can bypass an identist patient and do in a dent tape patient? Which is harder? How do you register the differences when there's teeth and no teeth?

SPEAKER_00 7:24

Yeah. So you you always need to have multiple quills, you know, in your, in your for your bow. I think that's the phrase that's used. You know, you you need different approaches to treat a problem. If you just have one hammer, uh, everything looks like a nail. And if something presents that's not a nail, you've only got a hammer. That's the only thing you can use, so you don't know how to treat. And when it comes to taking uh a centric relation record, and we're we're skirting around the elephant in the room, are we? Um the way you do it is probably a little bit different with the denture because of course you need um you need some bases to fit on the the dentilus uh ridges versus the patient who's got a a dentition has got teeth. And so the recording medium might be different. The way you stabilize the bases is you're trying to take the the denture, uh, sorry, the centric relation record means that you're probably using more of a chin point guidance technique versus if it's a dentate patient, you might want to use more of the bimanual mandibular manipulation. But even when you're working with a dentate patient, there's many times where you need to use a chin point guidance technique. Um and if you've got a denture patient who's, you know, got retentive base plates, you know, you'd want to use the the probably easier bimandibular manipulation. So you always need to know both approaches. And if you can use different materials, it opens up um, you know, your treatment options. So when I say different materials, I mean bite registration materials. So yeah, that they could be they could be different, but you're always at an advantage if you can do both. And so, yeah, if you're not doing much with or at all with complete dentures, then you lose some skill sets. Um, but also I think you you lose, you don't know what you don't know. And you lose the ability to uh you know, to to treat someone that comes in that's more dentalist than they are dente.

SPEAKER_02 9:19

Yeah. And on that topic, we had an opportunity in Mackay to put one of the dentists in the chair and and you showed how you do this in the in the real world, which I found very valuable because you use terms like chin point and bimandibular manipulation, and that all doesn't make sense, I think, until you see someone do it, or in fact, until you feel someone's hands on your own face and what that should feel like. But I think the challenge for me is we had a dentist in the chair and you were saying to them, Well, do you feel that interference? Do you feel that? And so when you're with a patient in the chair, you're looking for reproducibility. But what happens in that instance where you can't, you can't reproduce it? You're not sure if it's your technique or if they need to be deprogrammed. How do you know that you've nailed it? Is it just reproducibility that you're looking for when you are trying to register CR?

SPEAKER_00 10:20

Yeah, so I it is. I I think that um when we were talking about definitions, you know, the definition of CR is an anatomical definition. You know, it it's trying to explain where the condyle is sitting in the art against the articular eminence, and and you know, it's it's describing the position that is CR. And what is CR? CR is a jaw relation record. It's got nothing to do with teeth. It is where the condyle is sitting. And then we can talk about in a moment why that's important and what that gives you. But the bottom line is it's a conceptual position because I don't have X-ray vision to see into somebody's skull to see where the condyle is sitting. So I can only imagine it's in the right position when I can feel something. And that is the reproducibility that we're talking about. So being able to find that reproducibility, being able to feel the jaw arcing, as we say, where it's rotate, where there's purely a rotational movement occurring, is what you're doing clinically, but it makes sense clinically if you understand what you're doing in theory. Right. And that's where unfortunately definitions have made things very hard because the definitions are are anatomically based. They're saying this is where things are. And so straight away it loses people because the definition can also be really lengthy, a really wordy statement. Yeah.

SPEAKER_02 11:45

I think the other thing that I really observed is when you were finding CR on the gentleman that that put his hand up to be your dummy patient, um, he was saying to you, you know, as you do this and you're telling me to relax, I'm not relaxing, I'm really um working against you. And I think I observed that you're very gentle. And this is, we're trying to guide a patient into the position. But how much of it do you think you're doing, and how much of it is is your words inviting them to do what you want them to do?

SPEAKER_00 12:20

Yeah, isn't that the truth? You're conjuring. Yeah. It's like it's like some sort of magic or sorcery. I think that that is really important. And he made a good point. That the limitation of that demonstration was that I was trying to talk to the audience. I was trying to tell them what I was doing. And the more I spoke, the more information I was giving to the person being tested at the same time. So he started to think about his jaw position. And he started to think about muscle activation and fighting and resisting. And the more he thought about it, the of course, the harder it was to find CR on him. Um, some people will always have more muscle activity and and resist you, and some patients will be like a, you know, like the best oiled hinge you've ever come across, and their jaw just moves very loosely and easily. Um, he was probably at the slightly harder end and then made more complex by the fact that he was a dentist and thinking about all the information that we were talking about, it kind of helped him to brace up a bit.

SPEAKER_02 13:20

Would you your advice be if you're really struggling with that and you've tried and tried and you're and you're not getting anywhere? Is your advice to take a step back and give the patient a break? What how do you help yourself when you're in a position where the patient's fighting against you and you're just not able to find it? But you need to tell the laboratory, you need to register this position, but you're just in this little tango with the patient and you're not having any success. What do you do then?

SPEAKER_00 13:51

So the the question is what how how do you manage the patient that's not not helping you to find CR? Yeah. It's um you you really only have two choices. You can't fight the patient. In in the nathological era, um, CR was was thought of as a very precise, very mechanical position. And because it was a border position and very mechanical, the person finding CR's goal was essentially to overpower the patient and and manhandle their jaw back into CR and get that that arcing to occur, which is why you you hear all the stories of people being very sore after they've had CR found on them in, you know, by someone employing that that strategy. But I mean, arguably it works because you're kind of bringing it back to that position. I don't think that's the best way. I feel that for most people, you as you use the words, you almost have to coax them into the position. And so if you guide them, if you're not rough, if you don't lose their confidence, if you use the right words, if you imply that everything's gentle and in fact follow through with being gentle, you tend to find that that person's going to fall back into CR and allow that arcing movement to occur. And if they don't, then that's the person that you now have the two choices. And choice one is to try to deprogram them, and that's a word that's used a lot, and often no one follows up with what does that really mean. Um, and the second thing is, you know, is to try one of you know a couple of tricks that that might work, might get you close to CR. Um, firstly, deprogramming that essentially means that right at this moment that person is consciously or subconsciously thinking about their teeth being together, or at least being in full control of their teeth because they're in full control of their musculature and you've got to break that cycle. And so the classic way to deprogram is to make sure that person has their teeth apart for a period of time. And you can do that with something like a Lucia jig or or a leaf gauge. You can do it with a tongue depressor, you can do it with a cotton roll between the teeth, but you want them to have their teeth apart. You it's like you're trying to break short-term muscle memory. Um, and that period can be can be a few minutes, it could be an hour. Um, you know, and that that can be very impractical in a clinical circumstance, depending on how long that takes. Um, the other alternative is to try a little trick that, well, at least the one that I use is to ask the patient to take the tip of their tongue and touch their palate with their tongue, but as far back as possible. So they're almost trying to touch the uvula and to keep it there as they start from an open position to close and to just do it nice and slowly, keeping their tongue up there until they feel a first tooth contact. And um, for a lot of people that'll be CR or at least it'll be a more retruited position than their current MIP. Um, so that can be helpful when you're at least initially starting treatment.

SPEAKER_02 16:49

I keep referencing this hands-on activity we did in Mackay, and we we did actually videotape it, and the video will be available on the Correct Dentistry website. So please look it up if you're interested, and that will go along with the full day program on occlusion that we have recorded as well. So please look it up. It was a really excellent day, and it goes into a lot more information than what we're going into today. Um, when you were doing that hands-on exercise, I heard a little birdie in the audience say something that really interested me because maybe a part of me thought it too. You showed everyone how you register a bite for a splint. And it's it was really detailed and it was really precise. And we're not taught to do it that way. In fact, we're not taught a lot about splints at in undergraduate training, and and mostly I believe the way splints are prescribed in in private practice is you've got some wear or you've got some pain, and I'm going to make you this thing, and I'll give it to you, and I might adjust it or I might not. I've seen them hand it over the reception desk at practices, and I've seen right through to your technique, which is probably a nice hour of adjustment. But the comment from the audience was I don't do that. I just take a scan and it works.

SPEAKER_00 18:10

Yeah.

SPEAKER_02 18:11

Can you comment on that?

SPEAKER_00 18:13

Um Yeah, look, I mean, the the promise of digital dentistry when it comes to a splint is that in theory you can register the full arch, including sevens and eights, which which are often missed or partly missed on on conventional impressions. So you could register the full arch and the opposing arch in full, but with with really quite nice accuracy in order to fabricate a splint. If you can then put the patient into centric relation and register that bite, and there's really no reason that you can't do it the same way that we did it with a leaf gauge, then you should have a splint that's as perfect as you've designed it. You know, and and I showed um the prescription that I have for a splint, and uh and it's a PDF, it's available for download um in in the occlusion program. Those design details can easily be built into a digital program, and you should be able to have a splint that fits perfectly if you've registered CR perfectly. And even if you haven't registered CR perfectly, then when you go to fit it, the amount of adjustment should be really simple and it shouldn't involve very much. And and I've got no bones against that whatsoever. I think that that would be a wonderful thing to do. My only early experience with um with digital splints was the material that they were made from. So if the splint was milled or if it was, you know, nowadays probably printed, but it's made from a material that's not as durable as PMMA, um, that might be the only downside. So it could be a downside if it wears too quickly. Or alternatively, um, and and I'm referring to a colleague's practice. I can remember hearing the initial feedback, they started to do digital splints. And, you know, that they said that they're terrific, you know, things, things fit really well. And then about a year later, they saw a reasonable proportion starting to break. So I mean, that's a material failure, it's not a technique failure. So ultimately, um I think that the promise of digital dentistry for manufacturing a splint should be great. And even if they had a material failure in a year, you'd like to think realistically they could just reorder another splint without all of the records and get the same appliance sent to them that would fit as well as it did on the day they fit that splint. So I think the audience was correct in those comments if they're doing their respective stages correctly.

SPEAKER_02 20:45

There's a lot to cover on this topic. So we're going to take a quick break and we'll come back with more questions on occlusion in a moment.