Removable Pros for Students – PS009

Protrusive Dental Podcast

There is something very satisfying about a well fitting denture.

I am joined by our resident Dental Student, Emma Hutchison, to demystify removable prosthetics.

https://youtu.be/1hQGjKUa6MU

Watch PS009 on Youtube

Which joint position should we use for dentures? Is this important?

How do you calculate the freeway space?

What are we actually recording during a Wax Jaw Registration for complete dentures?

Don’t miss the special exam revision notes on Removable Pros available exclusively in the Protrusive Guidance app! (Join the free Students Section)

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

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If you love this episode, check out PDP162 – Occlusion for Complete Dentures

Click below for full episode transcript:

Jaz's Introduction: I think we all remember that phase at dental school where we were just confused by everything related to dentures. It was especially confusing because dentures are kind of like one of the first things you do as you're a dental student. So to you it felt like being thrown in the deep end anyway.

Jaz’s Introduction:
For many of us the denture confusion lives on and continues throughout our career. Hopefully with some of the older episodes in Protrusive we managed to make dentures more tangible. And I myself have been enjoying doing some cobalt chrome dentures, something I didn’t get to do much during dental school. But today in this Protrusive Students Section, and I mean students lightly because this whole segment, the Protrusive Students Series, whilst we release some revision notes for students every time we release an episode, what we discover here is revision.

Sometimes good to revise topics, go back to basics, so if you’re a young dentist or revisiting back into dentistry, or at any stage of being a dental student, this episode and all of the series of protrusive students should be relevant to you. Especially one we did a while ago about adhesive dentistry for beginners.

Lots of qualified dentists said how much they enjoyed that one because it was nice to just go back to basics. In this one, once again with our protrusive student Dr. Emma Hutchison, she asked me about all things that confuse her as a student when it comes to dentures. And because she’s relatively new to clinic, Most of the questions he asked was related to complete dentures.

So I hope you enjoyed this recap and this revision on the different stages of complete dentures. What are we actually trying to achieve in the various stages and what is important and what’s not important? Hope you enjoy and I’ll catch you in the outro.

Main Episode:
Emma Hutchison, welcome again to the Protrusive Student section. This time we’re going to cover removal. But just tell us, we’re recording this way in advance because we don’t want to interfere with your exams and stuff. How are you getting on? What’s your last few weeks been like?

[Emma]
Yeah, the last week I’ve only seen one patient, which was actually my flatmate, and didn’t need anything done. And so he just got a scaling polish, a bit of PMPR, and that was him really. So nothing too exciting in terms of patients, but just I’ve got my exam dates now, so it’s really becoming real, so just keeping my head down and getting through lectures and really starting to study now, so.

[Jaz]
What kind of learner are you, Emma? You know there’s different types of learners and stuff, I won’t give you any ideas, just in terms of self discovery, how do you like to learn?

[Emma]
I’d say I need to listen to things, I need to be told by someone who’s talking to me, and I need to be able to translate that into something that I can understand myself, so in my notes. That I make and that I’ve shared with people. That’s all come from listening to lectures and watching these lecturers live, like I need to hear it. I’m not too good with just reading things off of a slide. I need to be there, whether it’s a lot of our lectures are pre recorded. So yeah, very audio for me, listening to it and then putting that into something that makes sense to me on paper. And then I revise from that, really.

[Jaz]
I’m very much the same. When I was at dental school, very much audio based. Now back then, we didn’t have, it was everything was face to face, right? There was no like a watches on demand thing back when I was a student. However, I used to have this software on my iPad were a newish thing then.

And so I had the software called SoundNote. And so I’d be able to make my notes and it’s recording the audio at the same time. Anywhere I click on the notes, it’ll take me to that relevant part of audio. That was instrumental for me. That was really a big help. I’m also someone who likes to write and make notes. And just like you, make something make sense in my own language, in my own way. I feel like you said that.

[Emma]
Yeah, definitely. Like, you can say whatever you want to me, but I need to put it into a context that makes sense for me. And that’s what I work from. Yeah, yeah, definitely. Make it make sense for me. Yeah, definitely.

[Jaz]
Let’s make removable prosth sense for you as much as we can in the next 20 or so minutes. As a student’s perspective, I know you’ve had a few patients when it comes to removable prosth. So, come at me, what’s on your mind, Emma?

[Emma]
So the first question I’ll ask, probably because it’s the biggest, and I know you’ve done episodes on this before, I know you’ve done episodes on this before, and it’s all about a bite reg. If we’re in the locker room getting changed and you’re talking to your friends, what do you have today? I’m on Prosth Clinic. If someone says, oh, I’ve got a bite reg in, you say, God bless you, good luck. Because it just seems like absolute witchcraft, I don’t know what’s going on. So just a bit, quite basic, what am I trying to get out of that appointment?

Maybe some steps to help me along the way. But that’s definitely from a few people that I’ve told about what we’re doing with protrusive students. They say, can you please make a bite reg episode, because I don’t know what I’m doing.

[Jaz]
I love it. I love this because it’s bringing back memories of me playing. So I was in third year. I was playing FIFA with my flatmate in fifth year. So we’re playing FIFA. And I had my denture patient in for a bite reg. And I was kind of like revising. So what am I checking for again? Like what am I doing? I remember having the controller in my hand. I’m like asking these questions.

I remember this very vividly, actually. So, to answer this question, and I’d love to make it tangible for all, firstly a disclaimer, I am no removal pros guru. There are, in the top five things I’m good at in dentistry, removal pros is not in them, just because I haven’t done enough of it. Even though I did quite a lot of complete dentures and stuff during my time as a DCT, it was as a restorative dentist DCT.

That was pretty good. But that’s been some years now, but I’m not scared of dentures and I’m happy to, I quite enjoy the cases when they come through, but they don’t seem to come through as much anymore, but I’m definitely happy to answer that question because that’s related to occlusion and we can definitely do that.

So first thing to distinguish Emma is, are we talking dentures without teeth? Or are we talking partially dentate? We’ll explore both of them, but which one would you like me to go first?

[Emma]
Complete dentures, yeah. Dentureless patients.

[Jaz]
Okay.

[Emma]
If we can.

[Jaz]
Of course we can. All a bite registration is, these wax jaw registration rims, is where the technician has to put some teeth. They need to know how the teeth need to meet together when the patient bites together. They need to know how big to make the teeth, how big to make the incisors, and they need to know where the canines go, where the centrals go. They can’t guess that at all. They need the bite registration. The bite registration is giving that information.

And essentially, when they put the jaw registration on like an articulator, right? So they can actually mimic the, some kind of movements and do up and down. And sometimes they may get ambitious and do side to side, right? What we’re trying to do with any articulator is recreate the patient’s jaw on the tabletop.

That’s exactly it. So there’s a number of things that we’re trying to record when it comes to a complete denture wax jaw registration. And essentially all of it stems that the ultimate aim is how can we essentially give the maxilla and mandible relationship to the technician. So when they have it on their table, how far it’s apart and how big you want the denture, how much you want the OBD on their articulator is the same as on the patient, essentially.

That’s at the crux, that’s what it is. When you get back your upper and lower wax rims, okay, you’ve got to first try it in because the preceding appointments are so important, the primary impression, the secondary impression. If something hasn’t gone quite right in that, you might find that the retention is really lacking when it comes to your wax rims basically falling.

And sometimes it’s just because it’s a very resorbed ridge, but sometimes because actually the impression didn’t capture enough detail or didn’t capture the full depth and width of the sulcus. So it gives us information in that regard. Now, sometimes if you’ve got a really floppy one, you can use some denture adhesive on the wax rim.

First, what I’ve always been taught to do is when someone’s learning cosmetic dentistry, Emma, the best way to learn cosmetic dentistry is through complete dentures. Did you know that?

[Emma]
No, no, I’ve never thought of it like that, no.

[Jaz]
Cosmetic Dentistry is all about, when someone smiles, how do the teeth, how are they framed within the lips? And essentially, when you first try in the upper rim, the patient smiles, and all the wax you can see, you have to now imagine, that’s teeth, that’s actually acrylic teeth. So the first thing you want to do is have a look from the side, and look at the lip support. If the wax is coming out too much and what we call the nasolabial angle is too acute and it’s sticking out, it’s too full, we know that we need to actually trim back the wax.

And as you trim back the wax, you’re kind of imagining from going, from a patient with a large overjet to someone who’s getting more upright teeth, basically. So as you’re trimming away the wax, you’re imagining the position of those upper incisors change. So cosmetics is determined from the position of the upper incisal edge and the gingival margin.

So essentially you’re trying to recreate that. So once you’ve got the lip support looking about right, okay, and then you want to check from the side, it’s not looking too full, you can then determine how much tooth display we want. So, when someone smiles, how much tooth do you think we want to show, Emma?

[Emma]
A few millimeters?

[Jaz]
It can be, and the main thing is it depends on their age. It depends on their age. This is a significant thing, because as we age, everything goes south, including our lips. And therefore, as things go south, when you’re smiling, You’re showing less and less tooth structure, but also more importantly, it’s at rest.

So we actually call it the Emma smile. And you say, Emma, Emma. And when you rest at Emma, you take a photo and you see how much teeth you see. Now in young people, you can see about, four millimeters, but if someone’s about 60, 70, maybe you just want to see one, two millimeters. So if you get the patient, you get Emma, and you’re seeing a big block of red wax, you know, you need to go ahead and trim it.

So once you’ve actually got that at rest, okay, now you know that, okay, at rest, they’re showing, when they’re talking, they’re showing that much tooth, which is not excessive. When they’re smiling, then you get to see, okay, how much of the width of the teeth we’re seeing. And so essentially now, you’re, you can be adding wax, like if you want a Julia Roberts smile, you can add more wax buccally.

Can you think of an issue by adding too much wax buccal lingual direction? How to think about what issues, because this is high level, I’m not expecting you to get this, but maybe you’ve been taught this or maybe you can reflect on it. Even if it comes to a lower denture or an upper denture, if the wax equals the teeth and the wax is now going too buccal or too lingual and therefore the teeth are too buccal or too lingual, can you think of what issues that could have for your patient?

[Emma]
Is that to do with like your neutral zone?

[Jaz]
Absolutely. Absolutely assume neutral zone because if it’s going too nimble, then the tongue is going to be putting forces to it, it’s going too buccal, the cheeks going to give forces to it, so that’s going to make it less stable. But the other thing to consider is, when someone’s chewing, ideally you want the load going through the meatiest part of the ridge.

If your tooth is too buccal, for example, and the patient is chewing, now it’s kind of like cantilevering off the ridge, it’s way off, it’s off the axis of the ridge. So essentially, yes, aesthetics are important, but you’re kind of determined, you’re kind of limited to the shape of the arch form, okay, and where the bone is.

So the teeth go where the bone is, and the most common thing actually is we have this thing where if someone comes in and they’re skeletally a class two, right, they’ve got a large overjet, and they’re skeletally a class two. In complete dentures, the most common mistake a beginner can make is try and give everyone a class one.

You think that everyone should have a class one, and that’s a huge mistake. You need to follow the bone. So if someone’s skeletally a class three, make them class three. If someone’s skeletally a class two, make them class two. That’s a real top tip there when it comes to the wax. Because all of this is determined in the wax jaw registration. Any questions on the aesthetics so far?

[Emma]
Yeah, this might be a silly question. So, when we’re talking about lip support from a side on view, and, are you taking the wax as the tooth? Does that make sense?

[Jaz]
Yes, yes, yes, absolutely. The edge of the wax, the very end of the wax.

[Emma]
I don’t even know how to word it.

[Jaz]
I know exactly what you mean.

[Emma]
Yeah, that’s the tooth.

[Jaz]
That’s the edge of the tooth. That’s the buccal surface of the tooth, basically. So, whatever you do to the wax is going to happen to the teeth. It’s the final position of the teeth.

[Emma]
To the teeth.

[Jaz]
The angle that you’re making with the wax jaw restoration, if you just tuck that in, now the teeth are going in and now usually the lips are going in as well. So it’s about getting the lip support. So you actually want some degree of lip support. You don’t want to go the other way and make them too retrocline and the lips sag, but at the same time, you don’t want to have a really too full there. You can imagine being like a monkey, like, way too full.

[Emma]
Yeah. Okay. No, that makes sense. That makes sense. Thank you.

[Jaz]
And the actual flange itself. Sometimes the flange, the technician might have made it too thick in the wax. Sometimes you can thin the flange as well. You don’t want to be able to feel it with your finger through the skin that much basically. Sometimes you put your finger under the nose and you’re feeling this big thick wax like posteriorly it can fill the sulcus a bit more. But anteriorly it should be fairly quite thin.

[Emma]
Okay. No, that makes sense. Yep.

[Jaz]
So go with how much tooth display at rest, so the Emma smile. And also when they smile big, how much wax they show. And that’s like an aesthetic guide. You also have checked the lip support as well. The next thing to check is the occlusal plane. What do you think I mean by occlusal plane when I talk about the upper wax rim? How can you assess that?

[Emma]
Is that using like a guide plane or something?

[Jaz]
A fox’s guide plane. Well done. So use a fox’s guide plane, okay? And front on, you can kind of just get your mirror and kind of just eyeball it and get them to smile and see, hmm. Is it, first thing, we don’t want any cants. Yes. A cant is when a smile is going off to one side. It’s like wonky, okay? So from the front, while you’re looking side on, when you’re looking front on to the patient.

You want to make sure that the wax is level, like a bubble meter, like it’s completely level with the eyes, with horizon, right, from the front. But more importantly, from the side, I mean, from the front, it’s easy to see, but the reason we use the fox’s guide plane is to look from the side, because what if your absolute cruiser plane is drooping down, right, or it’s drooping up.

So ideally you want a nice flat occlusal plane. Now you can use different references, like the Frankfort plane, the Ala Tragus line, all that kind of stuff. For me, when they smile, unless it’s a nice line that’s kind of parallel between the eye and the ear. There’s different Frankfort planes, for example, different planes you can use.

You’re probably in the textbook, remember these names better than I can. But you just imagine the scenario you don’t want is you’re looking at the patient’s side on and they’re smiling. And what you see is you’re going like a gradient, like a diagonal line and more and more wax is going down. You want to have a fairly flatish occlusal plane and that’s getting the occlusal plane sorted of the upper.

[Emma]
Okay.

[Jaz]
So we’re done.

[Emma]
I’m still following you.

[Jaz]
Good. So, aesthetics, number one. Number two was the lip support as well. Okay, then we’ve talked about the occlusal plane. Okay, you can check that from the front and from the side. Okay, so all of this, we’re just on the upper one at the moment. We haven’t even touched the lower one.

[Emma]
Yeah.

[Jaz]
All this upper one at the moment. Can you think of what other bits of information we should be adding now? Have you done any of these appointments yet, these waxed jaw registration appointments yet?

[Emma]
I have done one bite registration, but it was just for a lower denture. The patient already had a complete upper denture that was fine.

[Jaz]
Okay, so yeah, that was easy and nice and stepping stone to this.

[Emma]
I’ve not had a full fill. Yeah, definitely.

[Jaz]
Okay, so this is trickier, it’s a lot more involved, but now what you want to do is imagine the technician gets this wax, right? How are they supposed to know exactly where the middle of the teeth could go? Where do you want the left and right central sides?

[Emma]
Midline.

[Jaz]
How do you, how can you convey the midline?

[Emma]
Yeah, I was going to say, I don’t know the nose?

[Jaz]
You can use the nose but it’s more about how do you scribe it onto the wax, right? So you can get like a wax knife, right? And you look at the patient and dead on you follow the philtrum, or you follow the eyes, bisect it, it just aesthetically has to look right.

Now, interestingly, with the midline, if you look at orthodontic studies, the midline can be off, up to about four millimeters of the lay person. And they’re not going to realize, so don’t take this one too seriously. But essentially, roughly in the middle of the face is good. And then now you’ve got your midline actually going to be really fancy.

You follow like there’s like the inner canthus of the eye, the middle portion of the eye. You follow it down and that’s roughly where your canines go. And you can actually give them that inform. That will help the lab determine exactly how big the teeth should be as well, how wide the teeth should be.

[Emma]
Okay. Yeah.

[Jaz]
You can now mark on the midline, the canines, and that’s also feeding into your aesthetics. Now is a good point to actually add in your lower wax rim. And so you can imagine you’ve got this upper one with a corrected occlusal plane, corrected aesthetics, and the lower one now is going to be When you get the patient to bite together, they’re just going to be usually hitting in the back only.

So the first thing to do is chop off the heels. Where is binding? Chop off the heels because whatever plane you’ve made in the top, you want to match it with the bottom. Should be like a mirror image in terms of occlusal plane, right? So that when you’re biting together, there’s like a nice contact all the way along the upper and lower wax rim.

So now you’re just heating it on a hot plate to get it to meet nicely and harmoniously with the upper wax. And so that’s not too complicated. And that’s just to make it reciprocal and balanced with the top one. The next thing you could do is mark the midline and the lower as well.

Okay. That’d be a good thing to do, but that might come a little bit later actually, because really what we need to determine first is the most important thing that was confusing everyone is the actual recording the bite itself. So, there’s two things about the bite. Firstly, it’s actually recording of the bite, the actual paste material that we can use to record the bite in different ways of doing that.

But most importantly, it’s the occlusal vertical dimension. And by now I’m realizing we’re going to probably use the next eight minutes just to iron this out and make sure you fully understand every aspect. We can cover the other bits in the future. Cause if this is the most confusing bit, let’s go with it.

You’ve got the upper wax rim in occlusal plane sorted. Aesthetic sorted. You’ve added the lower one and you’ve trimmed off the back and now they’re kind of flush. The upper one is flush with the lower one. Are you following me so far?

[Emma]
Yep. Yeah.

[Jaz]
Now what if you’ve done all this and the patient can hardly bring their lips together? It’s like stretching everything out. They can’t even bring their lips together. What clue is that giving to you?

[Emma]
You need to trim it down.

[Jaz]
The vertical dimension is excessive. Absolutely. The vertical dimension is excessive. Their lips are getting kind of pulled. And so really this is the bit where we try and determine the vertical dimension, so lots of different tricks and ways to do it.

Let me tell you about the way we did it in Sheffield when I was training. We got like, there’s a little bit of masking tape, okay? And we put it on the nose, like a triangular bit of masking tape and put it on the nose. Then I put a triangular bit of masking tape on the chin. So now a bit of tape on the nose, a bit of tape on the chin.

It’s like triangular, so it’s got a point on it. Then you get a compass, like at school, okay, and you want to use it to measure the distance between the nose and the chin, okay, but at what position do you do it? We want to basically gather the freeway space. Do you know about the freeway space?

[Emma]
Yeah, your freeway space is your RVD minus your OVD. Is that right?

[Jaz]
What does that mean though?

[Emma]
So-

[Jaz]
You told me it’s an equation.

[Emma]
Your resting vertical dimension. Your measurement between there and there when you’re at rest. When your jaws are just relaxed, like your teeth are.

[Jaz]
Teeth are apart. Okay, so here the teeth are apart. This is like you’re sat together, your lips are just together. Your teeth are not together, lips together, teeth apart. And your muscles, everything, your face at rest, no muscles are actually active at this moment in time.

You’re just at rest. Only then when you actually contract your muscles, the teeth come together. But at this point, the free way space area, okay, the resting position, the resting face height basically is this position, this relaxed position. Then when you bite together, your teeth come together. So the difference between when you’re at rest.

And when your teeth come together, that is the freeway space, that’s the amount of space available, basically. And so, if you put a denture in that’s too big, okay, you’ve kind of haven’t given the patient freeway space. So, the teeth are always clattering together, there’s no space to even rest their jaw without their teeth hitting.

And so that’s bad. So, what we want to do is firstly, for that individual patient, that unique patient, we need to calculate, at what vertical dimension is there freeway space? And then usually we can deduct some millimeters and make it the final vertical dimension, right? So how can we do that? So one way that I was taught to do it is get the patient to lick their lips and just start to bring their lips together and just very gently blow air so that the air is just, only just breaking the lip seal.

So I’m just going to try and do it for those who are watching, obviously for those who are listening, kind of follow along. But see that? My lips are almost as touching. I’m blowing air, my teeth are apart. And that’s a good rough way to measure the resting face height. Okay, so now you measure that. And it’s a good idea to measure it three times and you take like roughly an average.

So if you’re getting like wildly different numbers each time, you know the patient is doing something different every time. If you’re getting roughly the same, then you take an average, okay, and you’ve got that measurement, okay? So now that you’ve got that measurement, you know that your actual vertical dimension when your teeth are together is going to be more or less than that measurement.

So let’s imagine that’s a hundred millimeters. Okay, it’s way too much, but let’s say it’s a hundred millimeters, okay? When the teeth are together, is that measurement going to be less or more?

[Emma]
Less.

[Jaz]
Absolutely. Because now we’ve used up that three way space and teeth have come together. Okay. And so what we’re going to do now is imagine you put your wax rims in, and now the patient’s measuring at 105. You know that you’ve gone beyond your freeway space. So now what you do is you start removing. Which wax will you remove? Will you remove from the upper or remove from the lower?

[Emma]
The lower.

[Jaz]
Why? Why the lower?

[Emma]
Because we’ve adjusted the upper already.

[Jaz]
We’ve adjusted the upper already?

[Emma]
Yeah, we’ve adjusted the upper already, yeah.

[Jaz]
But for what reason did we adjust the upper for?

[Emma]
For your incisal levels.

[Jaz]
For aesthetics.

[Emma]
And yeah, okay.

[Jaz]
Yeah? So what we don’t want in a situation, if you start hacking away the upper, all that hard work with determining exactly how long the teeth should be, right, that’s all gone in the toilet. So really, the way to think about it is that the upper is for beauty and the lower is for function, in a way, right? So we get the upper right so that when someone smiles, they show the right amount of tooth. But the lower just has to tag along. Now, there are other ways to do it that other schools have thought in removal pros, but just sharing that the one I was taught and a commonly accepted one was, okay, let’s get the upper right in terms of aesthetics, occlusal plane.

And the lower one will just mash it up to follow along basically. So now you’re going to get rid of some wax following the same occlusal plane. So get a hot plate. Get rid of some wax and you keep measuring. Okay. And so let’s say you keep doing it and you get to around about a hundred.

So now you’ve matched your resting face height. But we want the teeth to come together a bit further along. So you’re going to remove maybe five more millimeters. So now we have a freeway space of five millimeters. Okay. So how would you determine this number of how many millimeters your freeway space should be?

It is a bit of a guess. Okay. So five, six millimeters might be what you might do the first time around. If it’s like a brand new complete denture for someone. But if someone already has a complete denture, really fantastic piece of information you can gain here. Right, so you do it, you use the measurement, all the dentures together, and then you figure out, okay, with their existing denture, what measurement they are.

So for example, Emma, if their resting face height is 100, and with their existing denture, their occluding face height, okay, the occlusal face height, for example, is now, let’s say 88. How much is the freeway space?

[Emma]
12.

[Jaz]
12 millimeters. And as a general rule of thumb, 12 millimeters is probably a bit too much. When the dentists that made a denture, they probably went for a three to four, five millimeter freeway space. How did it end up being 12 after all these years? Can you think of why that happened?

[Emma]
Continued bone resorption after tooth loss.

[Jaz]
Could be bone resorption. Something more fundamental. Let’s say it’s been ten years, they’ve been using this denture for ten years.

[Emma]
The denture’s worn.

[Jaz]
That’s it. They’ve worn. Dentures, dentures are worn, right? Old flat teeth at the back. And so now, maybe you’re measuring 88 on the old dentures. So what you don’t want to do now is go for a 3mm textbook freeway space on someone who’s used to having 12mm.

Maybe you’re now going to go for 5, 6 basically. It’s a top tip that Mark Bishop gave me when he told me complete dentures. So now that you know roughly where you’re aiming for, you’re now going to make sure that with the wax rims in place, the patient bites together with them and we’ll tell you about how to coach them how to bite together, but now you’re going to measure again and hopefully now you’re looking at something like 94, 95 millimeters.

You’ve now got the correct vertical dimension. What joint position are we actually in? This is where it gets a little bit complicated for students, okay? Because imagine the patient’s biting together, they can bite together and then maybe they can bring their jaw a little bit forward and bite together, and maybe they can bring their jaw a little bit forward and left and bite together.

They don’t have any teeth. So how can we take control of making like a reproducible position every time for the patient? Can you think of a joint position that we might use?

[Emma]
Your retruded contact position?

[Jaz]
Yeah. So also known as a centric relation or fully seated condylar position. Essentially, the condyles are snug in the glenoid fossa. And usually this is a very useful position because it’s a bit more repeatable. So, a way of doing it with complete dentures, you get the patient, the curl that’s hung back. And then close together. Because now every time, if you give that patient the instruction to do that, at least you’ll end up in the same place and you’re not constantly changing the vertical dimension and whatnot.

So that’s how you coach your patient. In a nutshell, that’s how you coach them. So now you’re in a situation where the upper one has got the midlines, got the occlusal planes, got the lip support, the lower one. You’ve also maybe adjusted occlusal the lip support a little bit. You’ve got the midline on, you’ve coached your patient to curl their tongue back and bite together. You’ve measured with the little triangles you’ve got your happy with the freeway space. You pretty much got it, but how do you send that information to the lab? Because if you send them the two wax rims individually, how the hell do they know how they go together? So, have you studied about different ways of doing this?

[Emma]
I’ve seen a few different people do it different ways. Sort of stick them together somehow.

[Jaz]
Yes, how?

[Emma]
Your two wax blocks.

[Jaz]
Perfect. How?

[Emma]
I’ve seen a few people cut notches into them and then use-

[Jaz]
Silicon registration paste.

[Emma]
Bite registration paste. And then get the patient to bite together and that’ll sort of just keep them in place by the time they get to the lab.

[Jaz]
That’s a great way of doing it and we’ll talk about that in a minute. A way that I think most of my prostho colleagues, they would suggest is not a great way of doing it is the following. A lot of good way of doing it is now, which some people still might do, is you heat the upper wax, you heat the lower wax. Now they’re both a bit sticky, okay? And you get the patient to curl their tongue back and bite together. This is called a squash bite. How do you think of what is the disadvantage of the squash bite?

[Emma]
You might sort of lose some of that freeway space if you’re softening that wax even more.

[Jaz]
Or you might give them more freeway space than what you wanted because if you’re squashing them together you’re actually decreasing that vertical dimension, right?

[Emma]
Right. Yeah. Okay.

[Jaz]
You might overclose them. That’s one. Number two is things might, things are slippery. Things might slip a bit and move the right, wrong position. Things aren’t hard anymore. So definitely cutting some notches, the way, the best way I have, I found is getting your wax knife, sinking it into like the middle where you imagine the lower right first molar would be.

So imagine where the lower right first molar is on the lower wax rim. You put your wax knife in and then you twist it. And essentially now you’ve made a little half sphere in the wax. And then you do the same on the lower left side and maybe a couple of the upper as well. And then you squirt your silicon bite restoration paste.

Get the patient to curl their tongue, bite together, observe that they’re going in the correct way, and then just get them to hold until the pace is set. Now, you can take it out all as a one piece. Now the beautiful thing is, even if it comes apart, because you put the notches in, the lab can now relocate them.

That’s the need for the notches. The technician now gets all this, and they can start putting the teeth in. You obviously select the shade, the mold. They can now have the correct vertical dimension. They’ll put the right aesthetics in, because you’ve told them how tall the teeth should be based on the height of the wax, and they know what the occlusion should be like, and the occlusion should be, it could be more class two, it could be more class one.

And that’s skeletally led. That was a whistle-stop tour from a general dentist who doesn’t do that many complete dentures. But as far as talking to students, if I was a tutor at dental school, that’s how I would be explaining it. So, and I’m happy to be vulnerable and say that, look, if there’s something I said wrong, I’m happy for the comments to say, you know what, Jaz, this is a better way, and we’re all community here, but you must tell me, Emma, is there anything that you did not understand? Anything you want more clarification on?

[Emma]
No, I think I followed you quite well there, actually. It’s good just to always get a few different tips and tricks from different people. I think that was all right, yeah.

[Jaz]
Good. I’m impressed by your learning skill. Now’s a great time to hit the textbooks, go deep into it, supplement it, listen to this really good BDJ guide, which I might have. I might post it to you on Complete Dentures. Emma, I’ll send you all my books and stuff.

[Emma] Oh, that’d be great.

[Jaz]
As a perk of the job, if you like. So I’ll get that over to you, okay. So, what revision notes have you got for the crush your exam section this month?

[Emma]
So sticking with this theme of prosthodontics, in second year in Glasgow, we did a lot of work on partial dentures, just a lot of things denture related, calculating your freeway space, prone denture design.

We did a lot of last year. Craddock Classification, Kennedy classification, all that sort of stuff, clasps, whatnot. Going to try and cram it in there, so, yeah, a lot of partial dentures as well, but we’ll throw in some completes in there as well and things, so.

[Jaz]
Great, so, it’s a real denture fest for this month’s notes. Amazing, we’ll add that on. You know what’s impressive, it’s worth reflecting on, in just the last couple of minutes here, is, when you go out into the real world, you spend a lot of money going to courses, And you can go in a denture course and pay 1, 500, 2, 000 pounds, 3, 000, whatever you want, right?

And it’s fundamentally, 80 percent of it is going over the same stuff at dental school. 80 percent of it, fundamentally. It’s just the difference now is a bit like have you ever read a book, Emma? I read a book, and then a few years later you read that same book again. Have you ever done that?

[Emma]
Yeah and forgotten everything that was in it.

[Jaz]
And you feel as though it hits differently. Like, you read it, and the different themes connected with you, which they didn’t before. So, the book never changes, but you change. So, in the world of dentistry, what happens is that we see our failures, we see someone more patient in the real world.

And now we are a much more receptive learner. And so when you come across the same content again, you’re like, ah, now it makes sense. And so make peace with it. It’s okay. It’s totally fine. And then, the more you learn now, great. You’ll save yourself a lot of money in the future, but it’s okay to do further learning and revisit some things in the future and only through the application of all the stuff, will you be able to actually grasp it fully, right?

[Emma]
Yeah, that makes so much sense because I can imagine, going back and looking at the things that you learn in dental school with so much more clinical context behind it would just make the world of difference. It’s completely different than when you were learning it when you were 20 and had five lectures that day and just so much information all the time and not really much context. So, no, that makes sense.

[Jaz]
Absolutely true. And so, maybe Emma, you’ll listen to this again in two years time. An even bigger light bulb with a higher wattage will shine brightly above your head. But I’m hoping that was helpful to you. And to all the students listening to this, thanks so much to students for listening all the way to the end here and check out the crush your exam section of Protrusive Guidance and Emma’s awesome notes will be there. Thanks so much, Emma.

[Emma]
Thank you.

Jaz’s Outro:
Well, there we have it guys. Thank you so much for listening all the way to the end. This episode is not eligible for CPD or CE, but Protrusive Education is a PACE approved provider and we have over 350 hours of CE on our website, on our app Protrusive Guidance. It’s also the place, if you’re a student listening or watching to this, you need to get on there for free.

So you can download the revision notes. These are beautifully made revision notes by our very own Emma, and she shares them openly and freely. And we spruce it up for her is hosted on the crush your exam section of the Protrusive Guidance app, head to protrusive. app. That’s the website. Make a free account and then email [e-mail]. Sending us your proof of being a student will accept you into the community and you can be part of our student network. It’s something that’s quite new and fresh with Protrusive. So bear with us as we build our library of content, but we already have all the previous months worth of revision notes to download.

And I know you’re going to love them. Emma spent hours curating them for you, and I know it will genuinely help you for your exams. Thanks so much for listening all the way to the end, and thanks to Team Protrusive for helping me put this together. That wraps up Removable Pros Month August, and September is Occlusion Month, so watch out for PS010, which we’re based, again, on occlusion. Catch you then.