OCCLUSAL EQUILIBRATION PDF

Yeah. Okay. Good morning everyone. So I hear that. Denture occlusion and natural occlusion are dancing side by side in your curriculum now, and I'm going to be doing some comparisons, but denture occlusion is. Is somewhat unique as compared to natural occlusion. And so we'll see how. And we'll see h...

Yeah. Okay. Good morning everyone. So I hear that. Denture occlusion and natural occlusion are dancing side by side in your curriculum now, and I'm going to be doing some comparisons, but denture occlusion is. Is somewhat unique as compared to natural occlusion. And so we'll see how. And we'll see how we use denture occlusion to protect. To protect the prosthesis, to protect the patient, to protect the bone. And natural occlusion, of course, is designed to protect the teeth and the TMJ. So we're going to be looking at the occlusal schemes. We're going to be looking at two setups. And you know what happens during two setups. Things that we can do to bring the tooth setup back into line before processing or milling. And then what happens after processing and how we can correct and equilibrate after processing. So the things that we can do. Okay, so we're dealing with three occlusal schemes. We have cusp teeth and a curved plane. So that would be our anatomic setup. We have our flat mandibular teeth and a curved plane. And this also includes a lingual eye setup for which you have been working with which will include a flat mandibular tooth and an anatomic or semi anatomic maxillary tooth, and then the flat mandibular teeth with a flat plane. So how to decide when to use curves? Now. What we did learn from the monoplane occlusion when you went through or monoplane or lingual eyes when you went through your excursions, almost every one of you had incisal guidance. If you had if your patient wasn't an edge to edge setup and hopefully your patients weren't an edge to edge setup. But if you had some kind of a class one or maybe even a little bit of a class two, almost every one of you had a little bit of incisal guidance only because. You know, you may not have had your condyle set correctly or we didn't have initially. When we set the mandibular teeth that we didn't build in any curves. And then we brought our articulator to an edge to edge protrusion of position. And what did we discover was the posterior was separated. And when the posterior is separate, naturally the anterior are going to touch. And so again what did we do. We went ahead and we created either a curve by taking a second molar. And we placed it and tilted it so that it would be in contact with the maxillary arch. Or if we didn't have room for a second molar, we added some wax in order to do that, to give us some proper balance. So basically what we're looking for is that anterior posterior balance when the anterior. Is basically we're talking about the horizontal over jet and the vertical overlap are sufficient, meaning there's sufficient space between the incisal edges are sufficient and the ridge is insufficient, meaning we have resorption on the posterior ridge, particularly the mandible. We say that we want a flat plane occlusion. Okay. On the second scenario where we have a flat plane, sorry, we have a flat cusp, but we have a curve plane when the anterior horizontal and vertical are insufficient. In other words, when we don't have enough horizontal over jet or vertical overlap. So we're going to need to create some kind of a curve in the posterior, whether it's a curve in the plane, whether it's the second molar or whether it's a balancing ramp. Okay. And in most cases, in most cases you're going to require one of those three solutions. So when horizontal and vertical are insufficient and the ridge is insufficient okay. So we have lots of patients with significant amount of resorption on their posterior mandible. And so this solution, whether it's a flat tooth or whether it's a lingual setup, this is probably the most prominent and the most popular suggestion in order to create an occlusal scheme. As far as the anatomical option, when the anterior horizontal and vertical are insufficient. And again, in most cases it isn't. And the ridge, however, is sufficient. So when you have good vertical walls. And we're going to see that in just a minute, when you have good bone, in order to support the denture and in order to support your excursions, then you would consider using an anatomical tooth. So you've seen this before, but it's very important and kind of very important for visualization. So if the occlusal plane is flat but the mandibular path is curved, which it always is, it's very rarely that you're going to have a canal or eminence that is going to be flat, flat. The posterior teeth will include in excursions. And I particularly pay emphasis on protrusion because there we have incisal guidance though your lateral intrusions, your lateral excursions will also fall into place and either provide you with group function on one side or even canine guidance if the canines are close enough together. You have to manipulate the anteriores in this regard to keep the posteriors in contact or create. What we're going to see is going to be, you know, that curve or balancing ramp if the occlusal plane is flat but the mandible mandibular path is curved, the posteriors will disclose. However, if we create that compensating curve. Oops. Going backwards. Sorry. If we create that compensating curve. So if the occlusal plane is curved and the mandibular path is curved, the posteriors will remain in occlusion. So this is we can build in that curve or we can create what we did in the lab, which is add the second molar with or without the maxillary second molar, or add a balancing ramp. Which is very important. Okay. Curves create balance, whatever the cusp, so we can get that balance even if we have a flat plane or a flat cusp tooth like the mandibular arch is. So how to decide what cusp to use? Well, let's take a look at these three scenarios. Vertical walls keep the denture from sliding off the ridge. I mean think about it. If the patient has a flat ridge, there's nothing there that denture is going to easily shift. Vertical walls of good ridges offer resistance to lateral movement. Vertical walls of ridges offer less resistance to lateral movement, and vertical walls of severely reserved ridges offer no resistance to lateral movement. During protrusion. So now we're looking at a flat, plain tooth versus a cusp tooth during protrusion. Cusp teeth stay in contact longer because of the inclines that are present than flat teeth. Okay. However. During lateral intrusion. Teeth deliver greater lateral force than flat teeth, so once the inclines contact one another, then the pressure on that mandibular denture is going to be greater and put a lot of pressure on those vertical walls of the mandible. If there aren't any vertical walls, what do you think is going to happen with the denture? It's going to slide because there's nothing that's going to keep that denture in place. Resolved ridges require flatter teeth, hence the expression the flatter the ridge, the flatter the tooth. During exclusive movements, the flanges exert pressure on the underlying bone to prevent the denture from dislodging. So if there is, for example, an occlusal discrepancy and the patient goes into an excursion, it might be felt here, but more than likely it's going to be felt down here where the flange is now pushing against the bone. So lots of times if a patient comes in and you have an occlusal discrepancy, the patient may develop a sore spot elsewhere on the denture. So it's not always clear where that sore spot might be coming from. And you might see a sore spot here and think, oh, the flange is too long. Let me just grind this here, when in actuality we've got a defective contact here which is causing this denture to push forward. So we have to be very cognizant of occlusal contacts okay. A posterior premature contact produces inflammation on the lingual alveolar ridge in the anterior and conversely or another way to look at it, lateral displacement. So if you have an aberrant occlusal contact or a prematurity of the lower denture may produce deflection of the denture laterally and inflammation of the mucosa near either near the occlusal error or on the opposite side because the denture is now being pushed to the lateral side okay, so the denture will dislodge and it manifests at the edge of the flange. So now we've got a couple of different scenarios here, and some are logical and some you know, we don't typically have a situation like this. But if we take a look at. Scenario by scenario. How to decide how much to raise the lower anterior. So typically, for example, we have a flat tooth and a flat plane. So it starts off similar to how we started off with a flat mandibular tooth. So the molar the molars are contacting surface to surface. We're initially where we haven't built in any curves. When we say that we have to have sufficient space between the incisors in the anterior, the incisal edges, for example, that lower incisor has to be sufficiently spaced horizontally and vertically, so you can't expect any vertical overlap. And you're going to need a little bit of horizontal overlap. So when the patient goes into protrusion. However, in reality most patients do have a little bit of overlap. So if we do want to build in some overlap, we've got to create a curve so that curve will compensate for the overlap. So if we do have a curve we can now with sufficient horizontal over jet we can now add maybe a millimeter of vertical overlap okay. So that's kind of the progression from this to this. And the incisal edge can now overlap just a little bit more okay. Does that make sense. All right. Now let's say you had a cusp tooth and a flat plane which you don't do. Because if you have a cusp tooth you're going to have to build in a plane. But let's say let's say you try to set a tooth on a flat plane, you're definitely going to be in a situation very similar to a flat tooth on a on a curve plane, because you can't get these in size of ledges any closer, because once you go ahead and go into protrusion, these two teeth are going to touch because you don't have any curves to help unwind this occlusal scheme over here once you add a curve. So once you add a curve to these cusps, now you can go ahead and build in. You can get those in size alleges a little bit closer because they will miss each other as the patient goes into protrusion. Notice that the inclines will come down. You'll be cusp tip to cusp tip, and now incisal edges will contact at the same time. Okay. Comparing to a natural dentition. Natural dentition. You expect your incisal edges to touch, so you expect anterior contact. Okay. We have what? Mutually protected occlusion in the natural dentition where we don't have that in a denture occlusion. Okay. Denture occlusion. We're expecting bilateral balance. So none of these can touch at all. The amount that it touches depends on the cusps and depends on the curves. Okay. So at minimum, at minimum, to achieve your balance, you're going to need some kind of a curve, whether it's a curve in the occlusal scheme itself, in the occlusal plane, or whether it's that second molar that's going to touch at the same time, the anterior touch, or whether it's the balancing ramp. All of those qualify as a compensating curve in order to achieve that balance that we're looking for. Yeah. It is underwater. Operator. So. So if I. If I understand what you're asking for, you don't automatically raise the the lower incisors. You're going to keep them apart as long as possible because you don't want them contacting in the anterior. But what you do is because we set the anterior first, we set them where we think they should go, and then the posteriors will then control. You know. Well, then control that protrusion of movement. If we find that the posteriors don't have enough contact as we complete the setup, just like we did, then we can either manipulate the anteriores, but we usually don't because there anteriores we will either raise that occlusal plane or add the second molar, or add the balancing ramp. So we can accomplish all of that in the posterior without it changing vertical, without it being visible, without changing esthetics. Yeah. You don't mind going back once, like for. Yes. So if I, if I got it right, let's say patient comes after adventures in place and does. And sore spots as their. The right thing to do is to check your occlusion. Always, always. And the rest of this lecture is going to be devoted to how to determine what to adjust. So yeah. Okay, so unlike what you've been experiencing with a lingual ized occlusion, which you're you only had one supporting cusp, and that was the maxillary lingual cusp against the mandibular central fossa with anatomic occlusion, the supporting cusp. We have two supporting cast, basically the maxillary lingual and the mandibular buckle. So those are your typical supporting cusps in anatomic occlusion. So there's a lot more moving parts to an anatomic occlusion. It's it's a much more challenging setup. And in terms of doing the setup maintaining the balance, it's also much more labor intensive and requires frequent recalls for your patients. These are ideal centric contacts. Most of the time we don't get them as perfect as this. But what I want you to look at at the moment is the ideal centric contact in terms of what the bull's eye appearance of contact. So when you're checking these contacts with articulating paper, a true contact is basically the bull's eye appearance where you have the articulating paper breaking through. These are light and medium basically smudges. And the true contact is when the cusp pierces the contact and has the light colored target in the center, and we call them bull's eyes. Those are the contacts. When we do occlusal adjustments that we are going to adjust as we go through our sequential adjustments. We don't go for the light ones because they may ultimately turn into bull's eyes, but we're only adjusting the bull's eyes as we do our adjustments. So just as leading up to it for an anatomical setup, we're looking at bilateral balance cross arch and cross tooth. So this is our centric. And we're expecting contacts. Actually let me go a little bit. Yeah. Here we go. So this is centric. We're expecting supporting contacts on the maxillary lingual and the mandibular buccal type contacts bilaterally with no anterior contact. At all in left working. As you can see, we have pairs of cusps in contact on the working side, so we'll have a pair of one supporting and one non supporting on each side, but at the same time on the balancing side. So we don't have a non-working side because the non-working side is always balancing okay. So the other side is called the balancing side. And. Well before we leave and look at the balancing side, we're going to look at the working side again. The medial and distal inclines are aligned. So as the mandible comes out and goes into the working movement, as you can see, the maxillary cusps are sliding through the mandibular inclines and they are relatively uniform as they come out. Also, the canine is not interfering at all. We eliminate any canine guidance by the way we set the maxillary tooth, as well as the way we set the mandibular canine and the first premolar. So now on the balancing side, when the working side have these pairs of cusps and contact, on the balancing side we have two supporting cusps in contact. Okay, but they are in contact now. We went through the jaw motion simulator last week when you saw kind of a very similar scenario. This is. We're looking at a clinical remount done in the operatory, at insertion or at tooth setup, what we saw in the jaw motion simulator. Was simulating a tooth set up in the virtual environment. And we were. I was explaining that when we do our adjustments, we're hoping for at least 1 to 2 contacts on the balancing side at all times, and that will help keep the denture from from its movement. Again contact between supporting inclines. And you can see in the graphic over here exactly what it looks like. The cusps are edge to edge. Medial and distal inclines are aligned. Here we're checking the contacts with a little bit of tissue paper. Right working and left balancing are the same as we saw on the other side. The reveal. So the reveal is going to look a little bit different than the reveal as in lingual ized occlusion. We're going to see a little bit less reveal than we do in lingual ized occlusion, because again, the buckle cusps are now in contact where they weren't sorry. The mandibular buccal cusps are in contact where they weren't before in lingual eyes. Occlusion. The reveal of the inner incline should be about 1 to 2mm. In left working, they will match up. And in hoops and in balancing. There'll be even contact on the supporting cusps. So now let's look at the differences between lab remount and clinical remount. Let's start with lab remount. If the setup was correct, why is equilibration necessary? So lab remount. You're in your setups in the lab. Now we're talking about analog processing okay. Because lab remount is not done in the lab for a digital setup because it doesn't go through a similar process. When it comes out of the milling machine, there's no articulator to put it on, although it goes through kind of a similar process where what they do is they'll scan the mill of the denture and they'll kind of overlay the scan to what it was supposed to have come out. They'll overlay the scan to the original scan in the computer and make sure that the tooth position is exactly the same. So they'll compare scan on top of scan and they'll look at the heat map. So that's basically the lab remount is what it's done. And then it goes into the finishing stage. So for an analog. Laboratory remount. We want to take a look at what happens in the pre-processing stages before we send it to the lab. So we have our setup now. Last week, the week before we did, you had your setup. Some of you were complete. Some of you are not complete. You're in the process of doing the wax up, maybe tweaking the tooth movement. What could possibly go wrong between completing your tooth trying and your patient's mouth and sending your set up for final processing? Well, if you tweak a tooth or two now, the tooth has potentially moved and and then you're going to do your wax up. So you're introducing some more heat into your setup and maybe the teeth will have moved again. So now there's the wax up. And during this whole process, has your pin been touching the table this whole time, or has your pin been even on the articulator at all? And has your vertical changed? So we can introduce errors in the pre-processing steps. Now, during processing, there's some interesting things that take place when the denture is inserted into the flask. It goes through a heat of exothermic reaction during the time that the plaster is setting around the cast, during the time that we're adding stone around the teeth. Or how about when the setup is sent to the lab? Was there any excess wax around the teeth? If there's any excess wax around the teeth and the wax is then melted out, the teeth can shift within the stone that's embedded. Or the dough, the PMMa dough that is then placed inside the flask in order to convert to denture base. Was that too thick and rubbery, so that when the flask is closed, it's unable to be closed entirely? So we can get tooth movement when adding your stone. You can get tooth movement if the teeth are not secure within the stone because there's wax left over on the teeth. You can get excessive vido because the dough is too rubbery and you can't close the flask. So there are again a lot of moving parts. Tooth movement during processing causes occlusal errors. Excessive video is a serious occlusal error. So what can go wrong? Right? Post-processing. There's the face preservation done before the final occlusion check. So I'm not saying you're we're not processing your dentures, but let's say you did some occlusal adjustments. Then you did your face preservation, which you all did. How many of you are going to do some more occlusal adjustments before. Right. So you can't do that once. Once you have completed your your tooth trying it's what's done is done. So that has to be done. See our registration. Was it correct? Did you perforate the your registration with with with the teeth? I mean, there's a big difference between taking a CR registration for an analog denture versus a CR registration for a digital denture. And we're going to go over that today in the SSC. One for the analog. We don't perforate for a digital. We do. And we'll talk about the reasonings then. Was your mounting stabilized when you did your your clinical remount? So was it stabilized properly? Was your clinical remount not in CR. Was the pin placed properly. Okay. Kind of scary, all these things that can go wrong. So this is just a summary of the before the during and the after processing makes you not want to go through this whole process. Right. All of these errors. So the point I'm I'm bringing up is all of these errors will reflect in your occlusion. So what we're going to talk about is how to correct it. What I'm also going to offer is that the digital process, the milling process is a lot more accurate. It doesn't mean that we don't do a clinical remount. It just means that we have to have the ability to understand the occlusion and to understand how to do a clinical remount in the event that it needs to be done. But the digital process actually eliminates a lot of these or most of these steps, if not all of them. So sequence of correction. The lab remount is done immediately after analog processing and before D casting and polishing. It checks video and it reestablishes video so it doesn't equilibrate. It just brings the case back into the proper video. The clinical remount is done at insertion in the chair with the patient. The purpose of the clinical remount is to be able to check centric, check the excursions, of course to maintain the vertical, but equilibrate the occlusion. So we reserve occlusal equilibration for when the patient is there. And then we can take that final centric and mount the case using the face preservation that we took before we sent the case out. So that's the difference between the two. It pretty much explains it. One is done in the lab by the technician, and only to restore the initial vertical that we sent them with the initial case. And the clinical remount is done when we get the case back and we're inserting it in our patients mouth. So we do the clinical remount with our patient. Okay. To understand the difference between the two. So our lab remount still has the remnants of the process. The case. The denture is never removed from the cast until the vertical is restored. So remember when you see these little notches here and there's a notch there. Remember when we had you notch the cast. The notches will give the technician now the ability to key the the cast back onto your mounting and then check to make sure that the pin and the processing line up. And if the dentures have any vertical change whatsoever, of course it's going to be extra vertical. Usually it's less than a millimeter if it comes out of the processing tanks and we're talking 2 or 3mm, then something happened during processing like the doughy denture based material. And so that really needs to be looked at. That's probably more of a processing error than anything else. But usually the average processing of an analog denture will result in less than a millimeter of vertical increase because of the expansion. And polymerization expansion and shrinkage. And then the technician is just going to go ahead and restore the vertical back to the original pin setting. Okay. And then that's it. And then it's diecast and finished. This clinical remount occurs. Chair side for both analog and digital allows us to equilibrate the occlusion while maintaining the vertical. So once we're sent back processed dentures or mill dentures at the correct vertical, then we it's our responsibility to maintain that vertical. Okay. Clinical recounts are still required for digitally fabricated dentures. As I mentioned, though, adjustments are much less likely due to the material properties and and milling properties of the digital process. Did you have a question? Okay. The. I thought I heard something. Okay, so just comparing the different types of setups and different types of processes. So for a monoplane denture or a monoplane with lingual eyes, maxillary teeth, you can do your remount. You can do some adjustments into orally. But again intraoral or articulator the required contact is any surface. And as far as what is ground, any surface or equally split. And we're going to go through this process. But this is kind of a summary slide. The BTI which we're going to do today, our BTI actually has an anatomical occlusion. So you're going to get a chance to work with an anatomical occlusion. But most of the occlusions that you're going to be working with in the treatment center or lingual eyes, you can do you will be doing your adjustments orally to bilateral contact with no specific areas and no specific sequence. Lingual ised insertion is on the articulator upper lingual supporting cusps with specific areas and specific sequence, and for anatomical articulator only supporting cusps, specific areas and specific sequence. So we're going to concentrate on the anatomical for the most part today. Remember, as I mentioned, we're going to grind only the bulls eyes. We'll leave the smudges if we go back and recheck with articulating paper. On the second pass. Some of those sponges will turn, but smudges will turn to bull's eyes and some will just stay smudges. Okay. Objectives. So first contact is the maximum contact so we don't have a hit and slide, maintain video, distribute stress, retain the cusp shape so we don't blow out a cusp. Smooth contacting surfaces achieve balanced occlusion. We're going to start with the monoplane or the lingual ized occlusion where the maxillary arch is semi anatomical. Mandibular arch is either 0 or 10 degrees. So very flat. So here's our desired contact and CR flat against flat. Or if we have that curved plane a.s not in contact. If we have a posterior interference in CR. So a single tooth out of place, basically what we're going, what we want to check is just each of the occlusal planes on the individual arches are flat. First, if we have a posterior interference, adjust any tooth basically that has gone beyond the occlusal plane. So as you can see, the lower arch is pretty flat. You can take even a flat occlusal plane and put it against the surface, and you're going to see that it's pretty flat. The maxillary arch. You're going to see if for some reason, that tooth slipped beyond the occlusal plane because of the processing situation, you just take that and bring it back onto the occlusal plane, and it's everyone's happy you're back to the desired contact. So that's pretty straightforward. More than likely most of the time when you have a monoplane occlusion. You put it in the patient's mouth and due to polymerization shrinkage, your first contact is going to be in the posterior. In fact, it might even be a heel interference. Okay. Especially if it's very close back in the heels. But let's say it's not heel interference though. You're always going to check for that first, especially if there's no contact at all posteriorly. Then you have to look further back. If you don't see any contact between the occlusal surfaces. You've got to look at the heels. If it's not heel interference, you're going to usually see the last tooth in contact. And again because of polymerization shrinkage. So. If all the teeth appear to be contacting the occlusal plane, then we're going to assess which tooth we're going to, which arch we're going to adjust first. So what do you think? What should we look at first? Why would we look at the upper first versus the lower? What criteria will we set up? So. Right. So what we want to do first is check the plane, make sure it's flat which we talked about last slide and then check the pad. So check the relationship of this second molar or first molar or last tooth to the retro molar pad okay. And if the occlusal plane looks fine and it's correct to the pad, then we don't want to change the lower arch at all because the lower arch is giving us our occlusal plane. Right. So at this in this situation, if the pads okay then we'll adjust the upper arch. So we'll leave the lower arch by itself and we'll adjust the or the upper arch. So adjust if the lower arch is and we let's say we set it to two thirds the height of the pad and it came back at two thirds. Then we leave it. If it's higher than two thirds then we'll adjust it to two thirds. And then once it's at two thirds, we can continue adjusting the upper arch. Okay. Everybody comfortable with that? Okay. So we're going to adjust. Let's say we're at two thirds. We'll adjust the upper arch from posterior to anterior because that's what happens if you have a posterior contact. You'll adjust from posterior to anterior little little little little until your back to the desired contact achieved. Yeah. Always aim the bullseye. Always. Well so on a flat plane tooth you'll have bull's eyes. But what you don't want to do is create a cusp. So when you're adjusting you want to keep that burr flat. You're going to primarily go for the bull's eyes, but your aim is to keep it flat. Now. Once you have it flat, because if you're contacting in the posterior first, your anterior are usually open, okay? Not only your anterior is open, but your vertical is a little bit excessive too, because usually with with some posterior contacts, the patient cannot close down all the way. So your anteriores are open. But then as you adjust and your desired posterior contacts are achieved. What might happen is now you may pick up some anterior interference. So how do we deal with that? So anterior interference in cars got to be dealt with. Not delicately, but also you want to keep in mind that you don't want to start grinding these teeth and, you know, creating some very poor esthetics. So what we like to do is bevel these teeth. So creating think of increasing horizontal over jet and decreasing vertical. And that can be done in basically two strokes by putting a bevel on it and not lopping it off, just shortening the tooth because that's pretty ugly. So we can create a where facet. And aware visit is something that naturally will occur over time as a patient will grind their teeth. But. You know, we don't want to let them do that, because in the meantime, there's going to be some anterior interference. So it'll be kind of similar as the patient moves forward into protrusion and potentially can pick up some incisal guidance. And the same thing will happen. We're going to take a look. We're going to take a look at where those bull's eyes are. And we're going to create a wear facet. So doing it at a 45 degree angle by increasing horizontal and decreasing vertical creating where facets. Does that make sense? Okay. So now let's look at what it looks like. We were just looking at the lateral view and protrusion. Let's look at. What it's going to look like in our lateral excursion. So this is a looking at it from the posterior desired contact and CR but. As we go into a lateral movement. Oftentimes if we don't have a curve built in, we're going to have a group function situation. So if we do. And it's already processed. What we might want to do is just either leave it in group function, or maybe create a gentle curve as we adjust, especially if the canines are far enough apart. So a posterior interference in lateral adjust the entire occlusal plane to create a curve of Wilson. And what that will do is as we adjust here, it's going to bring this side a little bit closer together. So and you'll see a lot of times over time when patients of this occlusal scheme will come back, they will naturally wear this curve right into their denture occlusal table. So you'll see a gentle curve that looks like a curve of Wilson. Right. Not so much in protrusion you don't see because they'll come back complaining more and they won't. But in lateral. So we generally we gently go ahead and do our adjustments so that we build in a gentle curve of Wilson. If we don't already have it in the occlusal scheme. Okay. So that's why I'm saying we don't typically provide a patient with a completely flat, plain, flat tooth. We do provide them with a gentle curve to start off with. But if we find that the curves that we're providing for them are insufficient, as we adjust, the adjustment enhances that curve of Wilson or curve of Spee. Okay. Yeah. No question. Yes. Okay. So we we know from the studio there's that idea of the seizure for each millimeter in the back is removed. Free. Is removal. Approximately. Is there anything similar to that? Literally, like when you show the. I think it's patient by patient. I don't I don't know exactly if there is, but I think it's relative patient to patient and the amount of angulation of the eminence. Okay, so basically what I've just said can be summarized in a single slide. For adjusting a monoplane or lingual occlusion with a monoplane tooth check for the teeth number one. If it comes through like that, check for teeth displaced out of the occlusal plane and perfect number two. Once that's done and there's still a premature contact, check the pad and perfect the lower occlusal plane to two thirds the retro molar pad. So primarily area C, but you might need to bring it forward a little bit to area B. Number three. Once the pad is at two thirds the height then adjust the maxillary area d maxillary posteriors again from posterior to anterior. And what if significant adjustments have to be made. So if significant adjustments have to be made and you're going ahead and you're adjusting the maxillary posteriors and you're pretty much wiping out the teeth, I mean, there's that's a real problem. That's something that I would have to revisit the construction of these dentures and potentially evaluate for either resetting new teeth or remaking. I would have to reevaluate the vertical or something went wrong. But let's say these dentures had to go home with the patient that day for whatever reason. And you were you were going ahead and adjusting and adjusting and adjusting and you finally know what? What? One more time. I'm just saying that. I found another monoplane. Okay. Yeah. No, I'm just saying, you know, you have to. You have to plan for the worst. And if if the best comes out, then you're like, wow, this is great. I'm giving you all case scenarios, but let's say you had a lot to adjust. You might at some point, if you're approaching the denture base, you might have to begin to adjust the lower again. I wouldn't adjust the lower past a half the height of the pad. We know that we can go down to about a half the height of the pad in terms of the occlusal scheme, but I wouldn't adjust more than that. And then at some point we have to revisit this and say, why did this happen? How did this happen? So this is not something that we would say to our patient, okay, we're done. You know, this is not appropriate, but. You know, we can use these ideas. We can use these thoughts, perhaps when we're going in and doing a BTI try in a BTI fitting and then something like this can be re scanned. And we have lessons learned for moving on to the next phase of re scanning, resetting new teeth so the digital process can fix a lot of this, where if you're already here in the final denture and you have nothing left but to restart the denture because you have no records that you would have were this not a digital process? If you had this in contact and. Your vertical was still excessive for whatever reason. Remember, you got this back from the lab at the same vertical as you sent it to the lab. So maybe the vertical that you sent to the lab was excessive. But if you discover that your vertical is excessive and you needed to reduce vertical, it's still the same areas. Area B and area D if you had to reduce vertical. Okay. Remember, flat adjustments don't create inclines or cusps unless you wanted to do. You want it to build in your curve, especially the curve of Wilson. Don't aim at the bull's eyes, but specifically like digging out a bull's eye. But create a flat plane while going for the bull's eye first. So that's the peak of your creating your flat plane. If incisal or canine guidance create a where facet. So we're going to see a close up of how to create a wear facet in a subsequent slide. So I won't concentrate on that for right now. So any questions about the monoplane? Okay, let's take a break and we'll do anatomical. When we come back. It's ten of nine. Come back at 9:00. When you were. Talking about creating the workforce, we were talking about increasing. Overlap. And then we would say, sorry, increasing the horizontal and decreasing the vertical. Correct. We're referring to the vertical overlap. Yes. Of the teeth not the vertical dimension. Yeah okay. Yeah, yeah. Overlap. But just to make sure. Yep. For sure. Thank you. Okay, let's get started. So as compared to. The Anatomical Occlusal Equilibration monoplane has a much less. A sequential occlusal equilibration. There is a very specific equilibration sequence that must be followed with anatomical occlusal equilibration. It starts with first centric interferences, moves on to lateral interferences, and then ends up with protrusion of interferences. And one really is very much dependent on the other. So what is an interference? An interference is any contact that interferes with the desired result. So this these are the all of the possible interferences. I know that it's a big handout with a lot of information on it. We're going to go through each one individually and kind of bring this back at the end. And it's going to make a whole lot more sense when we finish studying each one of these interferences. Centric lateral and protrusion. So first let's start with centric interferences. There are occlusal gingival interferences preventing the teeth from coming together in an occlusal gingival direction. And there are anterior posterior interferences preventing the teeth again from coming together but in a. Horizontal direction. So let's set the ground rules for all of our adjustments. And and looking at our anatomical teeth. So the ground rules are the maxilla. Our maxilla is stationary. Our mandible is movable. Okay. So that's number one. We're looking at the curve of Wilson. Because the maxilla is stationary, we are going to call the supporting cusps on the maxilla primary and the supporting cusps on the mandible of secondary because they are movable. Now, the thing that we know about supporting cusps is that grinding supporting cusps will result in a loss of vertical if the supporting cusps are on top of one another and we lose that support. So it'll result in loss of not only vertical but also centric relation. Now, how do we correct the occlusion without changing centric relation or vertical? Sometimes we might want to change, but sometimes we don't. So blue dots constitute the cusp and the red dashes are the fossa. So here we have a vertical interference that prevents bilateral contact. Okay. So here we have a cusp in this fossa that is preventing the other side from contacting. Patient closes down. And we only have a contact let's say on one tooth or one side. Okay. Should we grind the cusp or the fossa. The answer is it depends. You don't even have to guess because 50 of you. 50% of you will say the cusp and 50% will say the fossa. So before grinding, we have to check our excursions because we have to check what is happening between the cusp and the fossa. So we have to check right, left and centric. So if the right lateral excursion has no interference. So in other words, if that cusp is not an interference in the right or left lateral excursion, in other words. So remember when we said right lateral left work I'm sorry. Right working left balancing. We have these pairs of cusps that are in contact. And then the pair of supporting cusps on the balancing side. So this is a normal excursion right. This is what it's supposed to look like if it looks correct. So that you have balancing even though you didn't have centric if this looks correct and no interference. Right. And then we go again into left lateral excursion without an interference, then we don't want to adjust the cusp, because if we do then we're not going to have contact. Right. And this is a supporting cusp against a supporting cusp. So. And also let's go into protrusion and check the protrusion excursion. And that's the offending cusp. Right. And that offending cusp is now also in contact. And if in all three exclusive movements we have proper movement and proper contact, then we grind the opposing fossa. So. Centric interference, we're going to grind the fossa if the interference occurs only in centric. Be okay with. That. Okay. But if centric right. And lateral excursions have interferences. So now if it's the opposite, if here is our offending cusp and we don't have a balancing contact. So notice that the cusp is creating a situation on the balancing side where we don't have contact. And the same thing on the other side where we have a balancing interference and no working contact. So now that cusp is giving us some problems on the working side, and now the cusp is also giving us problems in protrusion. We grind the cusp. We grind the cusp. So. Centric interference. Grind the cusp if the interference occurs in centric and E centric. So. Centric only grind the fossa centric and eccentric grind the cusp. Any questions? Okay. I'll give you a second to catch up. I know, I know. I. All right, moving on. This is also centric. But this this is in a horizontal position okay. So again maxilla stationary mandible is moving. Let's take a look at the inclines. So our missile inclines. Of the lower are in blue, are distal inclines of the upper are in blue, so these inclines are in contact with one another on. The red inclines distal of the lower medial of the upper. These are in contact with one another. Okay, so just want to highlight what's in contact with one another. Okay. So now you're going to see some contact. So me of the upper distal of the lower. So we kind of shorten it. And we say muddle. And in blue. Double distill of the low. Distill of the upper meat of the lower demo. Now for a horizontal interference where one of these a pair of inclines are contacting and not allowing full centric, not allowing full contact. Okay, we're trying to get the patient's job back and what's going to hit in the contact is a medial of the upper against distal of the lower. Okay. The jaw is trying to slide back. So when the jaw tries to slide back it's the inclines that are going to be interfering which inclines will interfere. If the mandible is trying to slide back, it's going to be the medial of the upper to the distal of the lower. Okay. You've got that medial of the upper distal of the lower because the jaw is trying to go this way. The mandible is trying to go this way. So meanwhile the upper distal of the lower. So now that we know which inclines are potentially interfering, we have to decide are we going to adjust the upper incline or the lower incline? Well, we want to adjust the upper incline. Because is the upper buckle cusp of supporting cusp. Or the lower buckle cusp, the supporting cusp. So we're going to adjust the upper buckle cusp because it's a non supporting cusp. So if you had a choice to adjust supporting or non supporting you're going to adjust non supporting cusps. So that's why we're going to. For horizontal interferences when the mandible wants to go this way these two inclines are in contact. The medial of the upper is an incline on a non supporting cusp. So we're adjusting the medial of the upper. Versus distal of the lower. All all this information needs to do is make sense. At this point, I no doubt you'll probably want to listen to this again. Or just look at your notes and that's okay. Huh? I know. So in a vertical direction again we talk about centric only grind the fossa centric and eccentric grind the cusp in a horizontal direction. We're going to adjust the medial of the upper incline because that upper buccal cusp is non supporting. Yes. Yeah. The incline of the heel of the upper. Me. So you know how you're trying to bring the mandible back by taking the tongue and sliding it to the roof of the mouth, and then that kind of the mandible kind of releases and wants to slide back. And when it wants to slide back, it's the inclines that are going to direct that horizontal movement. It's the inclines that will prevent it from sliding where it needs to go. But only because. No no, no, it's just it's going to need to go faster, but the incline will prevent it from going back into centric. When we say back into centric, superior posterior, that anterior whatever term you use to. Identify centric. Okay. Now. Lateral interferences. We have a working side, we have a balancing side, and we have potentially canine interferences. So let's take a look at the working side so as we can see. As we know on the maxillary arch supporting cusps. Don't move. Secondary primary supporting cusps. Don't move. Maxillary arch. Secondary supporting cusps are movable. On the working side. Each supporting cusp opposes a non supporting cusp. So we have maxillary lingual mandibular lingual supporting non supporting mandibular buccal supporting maxillary buccal non supporting okay. So that's the typical working side. Grinding a non supporting cusp will not change vertical. Here are the centric stops. We have cus fossa, cus fossa, cus fossa, cus fossa. So the rule for lateral interference for working interferences grind bull, which stands for buckle of the upper or lingual of the lower. So buckle of the upper is a non supporting lingual of the lower is a non supporting. So if you have a contact on the working side which causes the balancing side not to be in balance to open, then something here is causing it to stay open. So we're going to check with our articulating paper and grind either the buckle of the upper cusp or the upper buckle cusp, or the lower lingual cusp. We're not going to touch those supporting cusps at all. Yes. We'll see where the contact is. We're going to check with articulating paper. So these either one of those two cusps depending on which is interfering. So by adjusting either one, depending on where your bull's eye might be or where the where the not the smudge, but where the contact is, and you'll see it as you go through with articulating paper and do your adjustment, you will restore bilateral balance. So now you're working your non your balancing side is back into contact okay. By adjusting those non supporting cusps. Without loss of CR or loss of vertical. Okay. Now on the balancing side there is a pair of contacting supporting cusps. If you grind either one of them, you're going to lose vertical. So what do we do? Well to maintain CR and vertical, we're only going to grind the inner incline of the secondary supporting cusp. The way we do that is, again, identify your centric stops and your eccentric contacts. We're going to use two different color articulating paper. We're going to look at when you go into an excursion. So we identify your centric stops first. And then switch articulating paper color and go into an eccentric movement. And you're going to see that eccentric movement on the incline. So now you're going to see where the incline is and where that contact is creating an issue for the working side. Once you know where your eccentric contact is. So we'll say it's right here, which opens up. There's your balancing interference, which opens up your working side. What we're going to do is we're going to grind the inner incline of the lower buckle cusp. Inner incline. Lower buckle. Cusp. Yep. As long as we don't go from cusp to as long as we don't contact the cusp tip and grind it down, then that cusp tip will still maintain vertical. Yep. So we've identified your centric contacts with one color articulating paper. You switch it to the next color and you go through excursions. So now you see where your contact is and where your exclusive movement is. Your exclusive movement will identify the inner incline. And so what we're going to do then. So there's your inner incline, which is where I mean, so this is an interference of the exclusive movement. So basically what we want to do is adjust that interference but not go all the way up to the cusp tip. Yes. Why are we? Yeah. Plus also where for the for this particular movement we're going with the secondary supporting cusp. So once this is adjusted. There we go. Once this is adjusted, when we remove that lateral interference using both color articulating paper so that you know where to stop and not reduce the primary contact. The primary contact should be back to where it was not touching the vertical, not touching centric and bringing the working side back into contact. Okay. Next thought. Reason for posterior disillusion on a lateral movement. Canine guidance. Exactly. So now what happens if we have our canines in a lateral movement and they're in contact. So for canine guidance and lateral we have three three moves. What we want to look at first is the canine itself. Did the canine move out of position, or is it longer than it needs to be? If it moved out of position, we may need to reshape it. So what we want to do is look at the offending canine first and see maybe we could potentially do something with the canine. If not, then the next step would be adjusting the lower first canine. It's usually the distal inclined. So we'll we'll address that first. The second thing we will adjust is the lower first premolar. And it's usually the medial incline. Then if the maxillary canine is not out of position. So we didn't have to re contour it because it didn't lose position, then the third thing that you would do is adjust the maxillary canine. So it kind of starts with the maxillary canine. Just again it's like that monoplane adjustment where you want to see if it's out of the plane first, if it is low hanging fruit, if not, if it's in good position, then it's first second and then re contouring this. And it's usually we've got to do something like increase the horizontal, decrease the vertical over jet and overbite. So not the vertical dimension. And we're going to see what is what we will need to do in terms of creating where facets. And when I say correct the first and or the canine and the first premolar by creating where facets on the inclines, we're going to see how to do that in just a minute. So for lateral interferences on the working side it's bull buckle of the upper lingual of the lower because those are non supporting cusps on the balancing side lower buckle cusp lingual incline only. And for the canine will if the maxillary canine is in perfect position then we'll do lower first canine distal lingual inclined lower first lower first premolar medial incline. And then third the upper canine. And we'll do the wear facets on all three of these teeth. Third protrusion of interferences. We have anterior protrusion of interferences and posterior progressive interferences. So in other words, we'll have incisal guidance for anterior and we'll have additional protrusion interferences in the posterior which prevents the anterior from coming into contact at all. So let's see how we handle each one of those situations. Again mandible is movable. Maxilla is stationary. We go into a protrusion of interference. Take a look at our supporting and non supporting cusps. Again maxillary buccal is non supporting. Mandibular buccal is supporting. When the mandible goes into protrusion, there's contact between supporting and non supporting cusp inclines. Usually it's buckle cusps only. Now you'll probably have the opportunity today to experience on your betties because they're anatomical. You will see that as the patient goes into protrusion. There's no lingual cusp contact in protrusion. So when we talk about adjustments, we're basically only adjusting inclines on the buckle cusps. So this is the reverse of going into centric. Going into centric. We had the the muddle situation of upper distal of lower. This is going in the opposite direction. And we're only looking at the buckle cusps. So this is the opposite. In most cases 99% of the time it's distal of the upper buckle cusps only. So and the reason why we're looking at the buckle cusps on the upper is because those are non supporting. So the distal of the upper is in contact with the medial of the lower. But we're not going to touch the medial of the lower because those are the supporting. Inclines. So once again, we'll look at a familiar picture for Petra interferences when the mandible needs to slide forward. And we're hoping to have contact simultaneously in the anterior. But we can't achieve that because we have these interferences in the posterior. We're going to grind the distal of the upper only and we'll leave the medial of the lower alone. So we grind. Double the due part of the. An acronym. And we'll achieve our desired contact of simultaneous contact in the posterior. When the anteriores are touching. So that's again going in a horizontal direction with our posterior. Inclines. Questions. We're almost done. I know. We need to do like from the back. Towards. It depends on where the. It might just be one incline. It might be that you set a second premolar and the incline wasn't exactly straight. So when you saw the anatomical setup and you saw as the patient went into a working movement, all of those inclines were perfectly lined up. What? And that was just because the two premolars should be at a perpendicular to the occlusal plane. But if it wasn't and it was just tilted a little bit, then that incline could have caused the issue where if a patient goes into protrusion now, it just may have opened up that posterior just enough for the anterior to provide for an anterior open bite. Yes. That's great. I don't know if. To US centric and. Horizontal. We'll go. We're going to recap. So reason for posterior disillusion. Incisal guidance. So incisal guidance and protrusion. Um. And here we have two solutions. We've got the horizontal and the vertical overlap. And we can correct it in 2 to 2 swoops. Basically, if it's still in wax, as we know we are going to take a tooth that's in contact and we're going to transpose it usually where they're sitting, maybe anterior to the ridge, we're going to move it over the ridge. What we don't want to do is take the tooth and tip it, because that's very anesthetic appearance to a mandibular denture. Plus it gives a convexity that is anesthetic and very bulky. So we're going to take this tooth instead of tipping it. We're going to transpose it to keep that concavity that we're looking for. But that's if the tooth is still in wax. If we don't have the luxury then and we are in a process denture already, then we're going to have to create a bevel. So how do we do that knowing the same thing with the vertical vertical overlap if we can of course. And it's still in wax, we're going to take the tooth and perhaps ridge lap it and move it epically so that we decrease the vertical overlap. I mean that's again low hanging fruit. If we can't then we cut a bevel. So how do we cut the bevel. So before we have some horizontal usually but we may have excessive vertical. So before we're going to take a look at how much the vertical overlap is. And we're going to maybe create a bevel that is going to take care of not only the horizontal, because by creating a bevel, it will also increase the horizontal and decrease the vertical. If we go straight across, that's pretty ugly looking. And you know, we just don't want to do that. But by creating a bevel we can round it off. We can still make it look like a tooth. Or we can create a where facet depending on what the patient's esthetic needs are. So we look at the overlap and then we create a bevel to one half of the overlap. We can do a half an overlap, we can do a half a bevel or we can do a full bevel depending on how much horizontal or vertical. After the bevel, you know, you can have a sharp edge, you can have a a deficit or you can round it off. So please interject something esthetic in that area when you do that. If a full bevel of the lower incisal is insufficient, and it really should be unless there was an error again during processing. And then we need to go back and revisit it because, you know, most patients will not accept significant adjustments like that. Then only only as a last resort, we can maybe consider taking a little bit of a concavity out of the maxillary lingual, but only as a last resort, and this will give additional horizontal space to that to the incisal edge situation. Okay. The last thing again. And you would never even consider going ahead and just doing the maxillary incisal edge because I mean what's the point, right. Again, some of. These. The reason why I bring this up is because I think you need to know how far you can take this before you're looking at replacement of teeth, jumping the case or remaking the whole case. So I think it's obviously important that you want to get this as close as possible to your tooth trying. And if there are some major changes that you have to make, you have to really seriously consider doing some remakes for the patient. So but this these are insertion adjustments that can be made where facets are not uncommon. But if you have to do anything beyond that you have to look at what went wrong. Okay. So protrusion of interference rules. So for anterior we add the lower wear facets for posterior. Again it's double which means that the distal inclines of the upper buckle cusps. So let's just take a look at. What happens now when you are evaluating your centric contacts and your exclusive contacts? So what we're looking at here, you've got some centric contacts. And you have an interference. How can you tell if this is a working or a balancing interference? So what you're what you're going to look at is where the, the line of the interference is and on which cusp it is. And if you can see where the smudge or the the movement of the articulator and the articulating paper, look at the cusps that it is marking. And say those cusps out loud. Buckle. Upper. Lingual. Lower. So that stands for the anachronism bull. And what did we say is the type of interference that you would correct with an adjustment on the buckle of the upper lingual of the lower. Do you remember that you may have to go back and look it up. So a working interference is corrected by an adjustment of the upper buccal cusp. Lower lingual cuff. So basically where the articulating paper is marking is where it's going to tell you you need to adjust. So it's not you're not really left out high and dry. It's actually telling you a just me here and adjust me here. But you just you need you need some time to absorb, you know, the movement and and you know, the, the setup that you're going to get today. You'll have to keep and you'll be able to look at it and look at the movements. And it will help you wrap your head around what you have to adjust so that this is a working interference. And the rule for working interferences is buckle of the upper lingual of the lower, which are non supporting cusps. Okay. How about this one? You have your centric stops and you have a smudge or workin