HFO CE Radio – Canine Impaction & Orthodontics
As a Hampton Roads referring partner of Hatcher & Frey Orthodontics, we are excited to offer continuing education to our local dental community.
Sit in on this quarter’s digest while industry-leading and board-certified orthodontists William Hatcher & Scott Frey chat about Canine Impaction and Radiographic Predictors.
Here are links to the articles discussed in this quarter’s digest:
- Etiology of Maxillary Canine Impaction: A Review – Adrian Becker, Stella Chaushu
- Prediction of Maxillary Canine Impaction using sectors and angular measurement – John Warford, Ram Grandhi, Daniel Tira
- Radiographic Predictors for maxillary canine impaction – Ali Alqerban, Reinhilde Jacobs, Steffen Fiews, Guy Willems
3 CEUs (Total Run Time – 1:00:48)
Key Points:
- Common causes of dental related obstruction 01:41
- Predicting canine impaction via radiographs 20:04
- Canine impaction & preventative measures in orthodontic tx 43:00
- Orthodontic tx recommendations for tooth crowding & impaction 47:08
- Oral Hygiene & Orthodontics 58:39
SPEAKERS
William Hatcher, Scott Frey
Scott Frey 0:00
Hello, everyone. Welcome to the inaugural episode of Hatcher & Frey Orthodontics. CE Radio. We’re creating these little micro learns that are going to be useful to the Hampton Roads dental community, going through some articles, and bringing on some guest experts. A lot of it’s going to be orthodontically focused, but if there’s anything in particular in the dental space that you want covered, and discussed, we can certainly go ahead and put something together. Make sure that you go ahead and fill out the information to do the quiz. To get your CE after, you either review the transcript of this episode, where you listen to you know the audio in your car or working out or whatever you have. But I am your host, Scott Frey, and William Hatcher is also here. So, we’re, you know, excited for this to kick off. I’m going to turn it over to Bill to say a couple of things, and we’ll get rolling here.
William Hatcher 01:00
So now welcome. We’re super, super excited, super stoked to be able to reach out and touch base; you know, it’s so hard with everyone going in 15 different directions with kids and grandkids, and all that good stuff that we wanted to find a way to reach out to you not only to introduce you to different topics that we find, but also to find out some topics that you guys are interested in there as well. So we can bring that on board, grab some CE, and kind of connect a little bit because everyone is so busy. So we’ve been thinking about this for a while, and we finally got the process up and running. So, with that being said, I’m gonna turn it back over to Scott, and we’ll get up and going.
Scott Frey 01:41
Yeah, I’m sure you know, there’ll be a few technical things that we’ll have to iron out as we get through this process and get it more developed. But today, the subject that we’re going to be covering is canine impaction and we’re going to be covering kind of the radiographic predictors. We feel like this is a really kind of nice way to kick things off. This is some information that everybody can use and apply right away. But we’ve got some, some papers here three great papers, that we’re going to be kind of diving into today. And the first one that we’re going to start off with is not really a study, but it’s a review of maxillary canine impaction so aptly titled Etiology of maxillary, canine impaction, and review, Adrienne Becker, you know he’s an excellent resource. He’s got a phenomenal website and great book, all about tooth impactions and, specifically, canine impactions. And, you know, this is a phenomenal paper because it kind of goes through everything that you know, in terms of the evolution of our understanding in the orthodontic field, about impacted canines, you know, why they occur? What we need to do to kind
of facilitate, you know, correction, but I’m gonna go ahead and dive in. You know, they kind of kick it off and I’m here up in the first paragraph. They kick it off talking about the general incidence and that’s roughly you know, one to 2% of people, you know, sometimes a little bit higher than that little bit lower than that, depending on the population. You know, obviously, as orthodontists we see, you know, a lot more you know, what would you say is the percentage that people come in who have like an impacted canine?
William Hatcher 03:24
Oh, goodness. So I would suspect at least once a day, maybe four out of five days, we between the both of us that there have been impacted Cuspids that come in?
Scott Frey 03:35
Oh yeah. Yeah, it’s funny because like, you know, one out of every 100 is certainly not what we’re seeing on a daily basis. Now, this study breaks it down into, kind of, four distinct groupings of pauses, which is, I think, a really good way to look at things obviously. I mean, some of these categories have some overlap here, but they talk about local hard tissue obstruction, local obstruction in general, local pathology, the departure from the, you know, or disturbance of normal development of the incisors, and then it goes into a little bit of hereditary and genetic factors. So, the local obstruction section I found really, really interesting because, you know, I mean, I was really unaware of, like, the background of what the initial thinking many, many decades ago was with paint on impaction. So they touched on this a little bit. They said that the speculation was that the non-resorption of the deciduous canine was actually the cause of the anomaly, which kind of stemmed from us removing, you know, primary teeth. And that’s still, you know, a very good approach. But it’s interesting to note that they thought that the
primary canine and its behavior was actually an obstruction rather than, you know, something going on with the dental follicle. You know, that. You know, that’s interesting, you know, what do you make of these, like, you know, this section, they go into a little bit of, odontomas, other hard tissue obstructions. I mean, certainly, that’s obvious. You want to comment on that a little bit?
William Hatcher 05:12
Yeah, sure. And most of the time, we see supernumerary teeth and odontomas around the central incisors and so forth. As we go through some of this, they’ll find out that whenever you have something going on with a central, whether it’s impacted from an odontoma or supernumerary, it vastly affects the canine on that side, to possibly become impacted, so, when you see that you can certainly see what’s going on that route. You know, and they speculated gosh, is it the chicken or the egg? You know, was it the canine that the primary canine that didn’t resolve that caused it, or because the erupting canine permanent canine didn’t come close enough to the follicle, it didn’t resort? So it’s back and forth. And so there’s been some words about that. But I think overall, any type of local obstruction that’s hard definitely can keep things from arriving.
Scott Frey 06:10
Yep. Yeah, they have. They placed it here. 41% of severely displaced canines displaced canines. That was the prevalence when there was some sort of odontoma obstruction there. The other thing is they touch on, they talk about and this gets into a little bit of like normal development and normal eruptive patterns, the position of the maxillary lateral, and the first premolar and they talk about and I think this is important to note, you know, basically, these are going to precede the emergence of the canine by three years for the maxillary lateral incisor and then one year for that maxillary first premolar. So the window is pretty tight between that premolar and the canine if that tooth is obviously not getting down and the routes you can see up here on the, you know, on page 559. Figure 4, you can see how that first primary bicuspid I’m sorry, is, you know, kind of deflecting that canine off and it’s causing it to collide with that lateral route there. You know, and this kind of gets into what we want to and hope to do to establish a normal eruptive path for these teeth. And, you know, to some degree it’s why the recommendation if you’re helping primary teeth out that are not going to come out on their own. Sometimes it’s useful to do the primary first molar and the primary canine on that side to kind of facilitate a proper eruptive path there.
William Hatcher 07:55
You know, we’re talking about, the odontoma and the supernumerary tooth, you know, having like a 40% chance but a higher percentage of that is palatal, which makes things even a bit more challenging. So, of the 40% of the displays canines 30% are palatable and 9% or so on a bottle and, and just for information, the contralateral side is only about 5% or less. So that kind of gives you an idea of how that can affect and then how it can push everything over to the palate. And so exactly more challenging.
Scott Frey 08:32
Yeah, that discrepancy. I mean, there’s some other examples here in this review, but it’s pretty clear cut. I mean, the local factors are what’s driving whether the canines are getting stuck. It’s not necessarily genetics. Obviously, genetics comes into play on you know, whether lateral incisors are missing, other things like that, but that really is genetics, that in fact, that in fact kind of creates the local environment which then in turn impacts the canine there. Now they get into local pathology as the next one, you know, mainly the soft tissue, you know, kind of pathologies and inflammatory lesions and this kind of their, their discussion of this reinforces the need for really good hygiene and just kind of regular dental visits. For patients out there. They talk a little bit about inflammatory lesions around primary canines causing cystic change in the dental follicle of the permanent canine which then you know, because of the hydrostatic pressure to flex that tooth or coarse and gets impacted, and then as I kind of scroll over here to page 560, you can see that they’ve got a really nice example figure 7, where you can see that very, very large cyst up there and the maxillary canines kind of just placed up by the nose there. When we go ahead and kind of refer these cases out, you know that if we see issues with the dental follicle, we’ll communicate that to the surgeon so they can kind of take some steps to drain it and do various other things to kind of help them. Do you want to comment a little bit about what we’re kind of sending over, you know, to deal with those?
William Hatcher 10:16
Yeah, for sure. Definitely. When you’ve got that cyst forming of whatever kind it is. You can see it’s almost pushed the canine back up to its original position in the mouth, some 22 millimeters of movement that it has to go through to get into the mouth. So getting that taken care of and maybe having an open drainage and all of a sudden the bone epithelial cells start producing the bone again and coming down this way and everything typically comes back in so you know, we talked about us seeing so many impacted cuspids but I think what I like to look at is what, Scott, what you and I do is we see a lot of these early on, and we’re able to do preventative, prophylactic removal of some of the primary cuspids if need be, and we can really minimize that number. So, I think the prevention is as important as it is taking care of when they’re impacted and not having to go see the oral surgeon for these other things, Scott.
Scott Frey 11:16
Yeah, exactly. Exactly. And that’s, you know, that kind of really segues us nicely into the next section on disturbances of normal development. And, you know, basically there’s, there’s a couple things at play with this, right. So we obviously need to be able to proactively determine which canines are in fact going to be impacted. And I think this is what this little review of the papers is going to be, you know, pretty informative for everybody out there. But then once we know that that canine is going to be impacted, what steps can be taken to help prevent a surgical procedure? Certainly going in and with an imminent or you know, kind of really severe impaction a surgical exposure can be done, we can bring that to thin orthodontically but being able to avoid that surgical procedure by catching things early, preparing the way is ultimately the goal of having this knowledge and applying it. And what they talk about here in this section is specifically kind of like that ugly duckling phase, where the size of roots are all convergent, kind of splayed out. We have that space as the canine kind of slides down. And as you
mentioned, you know, that 22 millimeters is basically on average, how far that canine has to travel from its initial position to get it in the mouth. So that’s a long way and I can take a lot of detours and if that space isn’t prepared in the correct way, that’s developmentally normal. We’re going to have essentially a local obstruction by either you know, the lateral route not being there, you know, defective anatomy within the maxillary first premolar kind of being in the way. So, we want to go ahead and if we need to make some modifications to provide more normal development in that area and facilitate the canine coming down. We’re gonna go ahead and kind of build in this idea of what it should look like ordinarily, into treatment. You know, you want to comment a little bit on you know, kind of how we’re approaching that.
William Hatcher 13:21
Well, I think that’s a great point, Scott. So many times when we start to see these canines become impacted, there’s usually an anomaly where the lateral root is, maybe it hasn’t fully developed. Perhaps it’s distally located and so things as simple as obviously removing the primary canine but also doing some limited treatment where we kind of move the roots of the central and the lateral mesial kind of open up like a funnel so to speak, and create a little bit of extra space and that typically makes a big big difference and allowing us to, to kind of prevent that from happening. And you know, most of the time, we don’t have to worry about it. But there are certainly times when that ugly duckling doesn’t go according to plan, and we need to step in and do some work.
Scott Frey 14:11
Yep, yeah. Figure 8 has a really really good example of exactly kind of what that normal developmental alignment should look like there. And, you know, this kind of gets into the guidance theory versus genetic theory, and they make some really, really great points here on what’s, you know, kind of to shape the philosophy of how people should be approaching these types of problems. To save us, you know, kind of a long story short is that it is guidance theory that is driving this so, you know, the immediate and they get into if you can see on page 563. They talk about basically the two keys here. First off, that the immediate environment surrounding an uninterrupted canine is in fact governed by genetic factors, right. So if we have a defect in the maxilla, if we have a missing lateral certainly that is genetically determined, but that is going to then impact the environment in which that canine’s erupting. The direction and progress of canine eruption is strongly influenced by environmental factors. And that’s basically you know, when you look in here, they have, you know, basically on the next paragraph, next section over, they talk about how 75% of canines are unilaterally impacted. So there’s something on that particular side versus the person’s overall genetics that’s kind of dictating how these teeth are getting stuck or not getting stuck. And if it was genetic, he would, it stands to reason that you would have it on both sides because there is an underlying genetic genetic problem kind of overarching, you know, everything that’s, that’s going on. So with this in mind, I mean, guiding the canines in to position adequately is the goal of what we’re going to be doing orthodontically if it’s, in fact needed, and hopefully, you know, we can take steps to avoid unnecessary rounds of orthodontic treatment by simply working with the family dentists to kind of wiggle out primary teeth that won’t come out on their own and just kind of direct traffic so to speak. I’m going to pop it on over to the proactive environmental alteration.
I think we’re gonna we’re already essentially touching on this as we’re kind of discussing guidance, and what we’re trying to do as far as preparing the way but you know, we can do this with
either Invisalign, braces, you know, any sort of appliance, you know, if we had some baling wire and, you know, some buttons, you know, we can do all sorts of stuff. But basically, the concepts and principles are always going to be the exact same of aligning these teeth in a normal way, letting these teeth kind of drop into position and you know, hopefully even avoiding treatment entirely. You know, do you want to comment a little bit on the genetic portion of that, I think, you know, it’s, it’s pretty clear, you know, from the literature that it is, you know, basically an environmental problem, but.
William Hatcher 17:28
Ya know, I, I would tend to agree with you, as well Scott, I mean, you know, some of the the activities of having small laterals or peg laterals or missing laterals, that’s genetic, but in the end that’s really affecting the environmental and the eruption. So I would lean that way as well. You know what some of the neat things are Scott that we talked about the behavioral changes and proactive environmental you know, it gives us a nice list of different things as far as extracting some of the primary Cuspids to help out or maybe the first primary molars and creating space for everything. They also talked about creating space and, and doing cervical headgear. Obviously, that is not in vogue and they talk a lot about some expansion on that area. And the neat thing with the Invisalign, or the braces that we do when we catch them at a younger age, is we’re able to make all this room without having to do the traditional expander. And in the literature, it really bears that out as well. So you know, there’s a lot of different ways to get things done. And certainly, you know, some of the ways that are less cumbersome for the patients or those that are kind of on the spectrum a little bit not able to handle certain types of treatments. We’re able to provide these types of corrections proactively so that they can be successful and they want to come back to the dentists or the orthodontist and hopefully minimize the opportunity or the impacted cuspids.
Scott Frey 18:52
Yep, yeah, they, you know, just to kind of wrap up on this paper, they have a really good example here. Figure 12 about how, when these primary teeth are being referred for extraction. You know, I think parents are often surprised at how long those teeth are because every other baby tooth that comes out has no root because the adult tooth is erupting into the correct spot. But when we go ahead and get these primary canines out, or primary first molars out, they’re going to have a substantial root on them because they were not going to come out on their own. And they do a nice job of kind of illustrating that there and Figure 12. You know that, that kind of closes it out really nicely for the background about canine impaction and, kind of the etiology there. And just the general philosophy that we’re going to be applying orthodontically in evaluating these patients.
Scott Frey 19:48
But the second article here, gets into prediction, which I think is also key, because if we’re going to recommend anything as far as treatment is
concerned, even if it’s simply, you know, removing a primary tooth, we need to be certain that it is
indicated and necessary.
Scott Frey 20:04
So being able to predict which canines are going to get impacted is half the battle. Now, John Warford did this study, you know, at a University of Michigan, several co authors prediction of maxillary, canine impaction using sector and angular measurements. Again, you know, the obligatory review talking about basically the incidence within the population 1-3% You know, in an orthodontic practice, you know, they can get incidences as high as that or whatever. And for patients, you know, certainly we’re getting at least one person today with an impacted tooth that shows up. But, you know, 85% of these canines, you know, and as we mentioned in the previous paper, they’re located palatally, it’s a 3 to 1 ratio of palatal to buccal impaction so focusing in on these predictors here, with impaction. Most of what we’re going to be gathering is related to palatal impaction types. And, you know, kind of, it’s a little bit different animal because there’s going to be different kinds of influences on why those teeth are impacted when it’s drifting to the palate versus the buccal. But we just need to keep that in mind as we look at the kind of data that we get from this. Basically when we get in here, you know, the predictors, they talk about the treatment options here, if we get into the second paragraph on page 652.
Scott Frey 21:42
They go over basically the fact that we have extraction of primary teeth, or, you know, basically doing some sort of surgically driven treatment plan and we hope to miss that. That second part there by recommending primary tooth extractions at the right time. What is, you know, when you and this is kind of a good segue in there, what, what’s been the traditional kind of, you know, metric that they would always tell us about, overlap with the permanent canine on panoramic X rays.
William Hatcher 22:21
I think as far as the sectors that we have that we talked about, you can see in figure 2, where sector two is kind of the medial of the lateral incisor, sector three is a little bit further. Sector four is right across that way, Scott, and what they’ve always said that if you just start across the route and sector to that, if you can make room or remove the primary costs, but the numbers I was always here would be like a 78 to 82% chance of that cuspid coming in, and that seems to be there. Even if it’s in Sector three or four. Typically, we go ahead and remove the primary customer because it’s kind of holding things up. And I’ve seen in Sector Three where those cuspids will spontaneously come in and do great, sometimes you got to go in there and make a little bit more room. And that’s the other thing is once you’ve removed the primary cuspid, if you’re doing some treatment, you can keep that root of the lateral mesial and open up more room and almost move it out of sector three to sector two, and then that really kind of helps take care of itself. So I love the sectors. It’s simple and it’s easy and it’s easy for the parents to understand kind of what’s going on Scott.
Scott Frey 23:34
Yeah, and that’s, that’s a great point about the synergy with basically removing the primary tooth and then also making space, it’s going to really stack the odds in our favor. You know, just removing it on its own. We’re getting, you know, four out of every five three out of every four is kind of like the general time range or I guess percentage range of what is going to be a good response. But if we’re able to get in there orthodontically on top of that and open up space and create that proper, you know, developmental pattern that that canine wants to find a funnel its way down. That’s just going to increase the odds and it’s funny. So Lindauer he’s the one who came up with the original kind of, you know, sector analysis there. And he’s out of VCU. I know Steve a little bit you know, basically, he has method identified up to 78% of the canines that are destined to become impacted would be in sectors two, three or four. And that makes sense. I mean, once you start to see that overlap, that’s a really good indication that it’s not coming into the correct spot, and it’s going to require some intervention. Now with this study, they basically all got the same patients from one orthodontic practice. The chronological age of these patients was less than 12 years old. The impaction status of the interrupted canine was unknown for either or both teeth, at the time that these records are taken. No treatment was begun until impaction status was determined, and any eventual implications, or impactions, in this study were palatally located. They had about 200 patients initially, but they whittled that down to about 82 patients because they needed to all have the same X-rays taken for that patient taken on the same machine. So that was very consistent for the examiner to look at the angles and look at the sectors Now one other important thing to note is that this is a two-dimensional study. So they’re looking at these angles and looking at these sectors, but they’re only looking at it in two dimensions off of a panoramic radiograph. We’ve got a three-dimensional study we’re going to cover a little bit there’s some important differences. Usually more data leads to better conclusions, and we’ll kind of see why that is now.
Scott Frey 26:05
They went ahead and used that back you can see for the angles they use a bicondylar line there in Figure 1 and they can measure the angles of the long axis of those teeth, and that’s how they determined, you know, basically they put it into kind of 15 degree chunks. So there was kind of like different buckets of how angled those canines were coming in. And then obviously they had those four sectors that you see again in figure 2 there with the different lines across that lateral defining those sectors. Now, what they found with this study and this analysis is interesting because there was not any significance related to these angular measurements, all of the significance that they found statistically, and clinically, obviously, was related to the position of the tooth within those sectors. And I think this is you know, part of this and you’ll see the differences in the 3d study. The way that we’re going to be looking at these different
angles, is very, very limited in two dimensions. Getting a 3D image of what’s going on, really, really makes just life easier. And you can kind of see in this study, you were, I would say, if we’re trying to predict things, we want to go ahead and get out in front, and when it starts to overlap and get into sector two and three, it’s already kind of becoming impacted. I think we can catch it earlier with really good predictive measures and that can kind of help us out a whole lot. So, did you want to say anything about I guess their findings here?
William Hatcher 27:53
Well, I really to your point, Scott, the more information you have, and 3D is where it’s at, the more you’re able to see and decipher and make better decisions. And so we’ve got two studies, one with 2D and one with 3D and, and they’re off a little bit, but I think we can truly see when we get to the third paper by not having the 3D and the in this study right now. You’re unable to really make conclusive results or the ones they have are different. And I think, as you stated, the more information we have the better.
Scott Frey 28:29
Yep. Yeah, they found I mean, almost a factor of nine per sector. But again, the sector’s it’s too late because that tooth is overlapping already. And we just loved simply catch it earlier. So that way, the odds of not needing a surgical intervention are increased. So the last paper that we’re going to go through.
William Hatcher 28:55
And before we get to that, just I think the bottom line on this study, is that when they get to sectors two, three and four, it’s pretty definitive at an 82% clip that they’re heading for impaction. So something needs to be done. They told us that we can either do intervention or we could do the impaction. And, and with getting surgical extraction, we can get the same results. But which one is less invasive? The one or we do intervention, or the one where we let it, we watch it go to impaction and then we have to go to the oral surgeon. I know if it’s my son or daughter I know which one I would rather do for sure.
Scott Frey 29:37
Yeah. Absolutely. And that’s I think that’s a great way to segue into this last paper here, Ali Alqerban radiographic predictors for maxillary canine impaction. Out of the American Journal of orthodontics, they did this study out of Belgium. So it’s a European sample, you know, not really that much different than the US here. But again, they talk about incidents here and you can see, you know, the treatment choices are influenced by a lot of factors, right canine location, the severity of the impaction, how old the patient is, and we haven’t touched on it in this these papers here, and they haven’t actually done it in the review. But when they talk about patient age, I mean, when we would typically see them, you know, in the teen and preteen years, I mean, there’s really not an issue. It’s once they get older than 30 or 40 years of age. That is where the tipping point starts to create issues. Well, there is a tipping point that creates issues for getting these canines in. So, the likelihood of ankylosis, which means that the canine is going to be fused to bone somewhere, is about 50% once someone reaches the age of 30 and above, and then it’s basically 80% of the time, once they reach the age of 40. So over 40 only 1 out of every 5 impacted canines is going to even want to move if we tug on it now certainly we’ve gotten in canines in older patients, it takes forever. You know, do you feel like it’s worth it? Sometimes when we go ahead and fish those guys out after like, what, three years or something?
William Hatcher 31:18
I don’t know. I’ve had a couple of young females in their 40s. That said, is it too late just to extract it, like we only need a couple more millimeters to bring it in. But, you know, to your point, the older the patients are, kind of more of the bass quality can happen. You know, as far as maybe the gingival tissue not responding quite as nicely, having some recession, having some bony defects in there as well. So certainly the earlier the better, and again, not that we can’t go get them but sometimes the treatment is worse than the problem, according to the patient’s.
Scott Frey 31:54
Well, I mean, I think we’re you and I are probably the only ones that are really happy when the tooth is in the patient’s just exhausted, I guess at that point, if it’s, if they’re, you know, in those older age groups, getting those in because it just takes it just takes a long time. You know, and that, again underscores the importance of early detection here. You know, we provide as a community service complimentary screenings to all patients young and old, to be able to kind of provide this peace of mind with the dentist and the family. So if you can get in I mean, we can then start looking at “Alright, well do we need to do anything? Is this canine gonna be impacted? Are any teeth gonna be impacted? And then is there anything imminent that needs correction now?” and they go through in this paper you know, the removal of primary canines creating space extraction of deciduous, first molars, expansion to gain space, all of these things designed to avoid the need for a surgery. But it’s key. It’s very key that we get good information to be able to effectively predict this and that’s what this study was designed to examine. You can look here, they had 65 patients aged nine, nine and a half basically to almost 13. And a little over 13 and a half. Mostly girls, in some boys and that’s actually, you know that bias is you know, they’re in the epidemiology data out there. There’s more girls that are going to have impactions and boys, for whatever reason. But basically, one investigator did all of the measurements and analysis and there’s an extensive list of variables that they looked at, then that’s the huge difference between this study and the 2D study.
Scott Frey 33:44
I mean, 2D study had two things that they were looking at. This one had, I mean, it’s a lot and I’ll go, we’ll go through that in a second. But with that, they were looking at each one individually, and then they were going to try and create a formula to be able to predict this with a reasonable degree of certainty. You know, obviously, they felt like they could over fit the model and that was a bit of a concern, but we’ll kind of unpack that a little bit. So they looked at crowding. They looked at where the deciduous canine, you know, what its status was. Was it missing, had it been extracted? They looked at canine development in terms of the overall root length, whether the apex was closed, that lacerated open at the time that they were looking at the rotation of the canine that they could also see because there’s a 3D x-ray. And then you know, things like the you know, being assigned to a category no impaction, vertical impaction you know, buccal, palatal and then also they looked at the the roots of the first premolar as categorized as single root, separated roots, fused roots, and I think that’s important as well, because you can’t necessarily always see that root anatomy on 2D X-ray, but you can see it on these 3D ones. They looked at the contact relationship between the canine and adjacent teeth, whether it was the premolar or the lateral, and then they took some linear measurements here. Canine cusp tip to midline canine cusp tip to occlusal plane so that vertical position was assessed
canine apex to midline the width of the canine, the width of the lateral incisor, lengthen the lateral incisor and the mesial distal space available between the canine or between the lateral incisor and first premolar for the canine.
Scott Frey 35:44
And lastly, they had the angular measurements angulation to midline from the coronal view, angulation to the lateral incisor, again from the coronal view, the canine angulation relative to the occlusal plane, so the attitude of whether that canine was kind of nose down or not, and then the lateral incisor inclination to the maxillary plane was also looked at. And that’s pretty extensive. I mean, is there anything I don’t think they missed anything, honestly.
William Hatcher 36:14
Scott I was looking at, I was looking at this one. When I was in school, working on our masters, my most favorite person on a master’s program was a stats guy. He was a PhD stats guy, and quite often because he could take all these numbers and these are extensive numbers. I mean, they put a lot of time and energy to get this accurate, but you’ve got to have someone that can decipher it and run all the analysis and so I’m pretty impressed with how they went through this process. It’s pretty awesome.
Scott Frey 36:44
Oh yeah. Yeah, it’s, you know, more. You know, it’s always nice to really get a comprehensive, you know, look at like what they did here and you know, they whittled it down. So as we get into the results here, they whittled it down to about six key variables that they were able to include in that multivariate analysis. We’ll get to that in a second. But you can see that with the measurements and the variables that they were looking at, we can get to Table I here,
which looks at the canine related variables and their association to whether the tooth was impacted or not impacted. So these are just the variables for that first section there. And what they found was that in the impacted section, you’ll see that the canines were rotated pretty significantly as compared to the non-impacted canines. The crown position there was a significant tendency for it to be out of the line of arch. So it’s either palatal or buccal and again, it was like, you know, significant, you know, kind of leaned towards being palatally positioned with the impacted side, or impacted tooth I should say. And then there was, in fact, contact with the lateral incisor. So the interplay between It wasn’t that they were totally missing it, but there were the interplay was significant. Some of them even had contact with the central incisor or the first premolar when it was impacted, so these local obstructions certainly coming into play with what happens when these teeth kind of come down. Going on to table two here, we can see that they compared linear measurements now here. So and they found that the position of the canine relative to the midline and this kind of gets into that sectors analysis, right, so we’re talking about linear distance, and I would say that’s a close approximation to what they’re looking at here. The canine tip to the occlusal plane, so if it was way up high or close to the midline, it was going to be more likely to be impacted. And the mesial distal space at the occlusal level if there was a lot of crowding, there was not going to be obviously room for that canine to be in the correct position and it would make it somewhat likely to be impacted. I will say that, you know, just because there is crowding doesn’t mean we have to jump in and treat it. I mean, that’s that’s a very dangerous, like kind of, you know, trap that people fall into to over treat patients early. You know, the, this paper, other papers 85% of the time, they showed that the actual crowding was not what was causing the impaction but it is a contributing factor of mainly buccal impactions has been my experience. I don’t know about you, you know, do you want to weigh in on that a little bit?
William Hatcher 39:46
No, I agree. I find it to be more buccal. And the one thing when we have patients come into the office, I always say there’s needs tos and want tos. Just because you have crowding in there that doesn’t necessarily warrant to do treatment unless the parents want to do it. So we may not need to do treatment, they may want to do treatment, or we may not need to do any treatment, and they don’t want to do any treatment. So really, it’s a combination of just going over the pros and cons and educating our parents and that 3D X-ray really does an amazing job of just showing the knowledge as they say, you can tell me or you can show me showing is always better than telling.
Scott Frey 40:29
Yeah, and there’s the the they’re working on. They have it for 2D radiographs now, but there’s an AI component. I mean, there’s a company called Pearl that’s out there. For your normal two dimensional radiographs, they’ll be able to identify and highlight problem areas, caries, calculus, all sorts of stuff. I think visualization tools are super important for communicating problems to patients, also for us keeping track of them. But you know, as you mentioned here, now that we’re getting into the 3D realm, we get down to Table III. And as opposed to the 2D study, which had no angular measurements that they found were significant and only basically linear slash sector kind of measurements, were resulting in any sort of significant patterns developing. They found that the canine angle to midline canine angle to lateral incisor and canine angle to occlusal plane. Were all highly highly highly significant when it came to when teeth were going to be impacted and determining and predicting that. So they went down now and to you know, Table V here, they look at as they went ahead and kind of put all of this together. You know Table IV, they have the results of the multivariate, Table V was the results of the final prediction model and kind of how they weighted things. But what they looked mainly was the crown position, was it buccal or palatal or in the line of the arch and if it was palatal, there was a significant was 20 was the odds ratio that it would get impacted, you know, only almost eight for buccal position. The customer to midline also again, was, you know a factor and the angulation of the canine to the midline and the lateral incisor. And then also, it’s you know, position whether it was you know, relative to the occlusal plane so, if we were to see a tooth that’s higher up, okay then its counterpart on the other side, we would get a little bit concerned because obviously something locally is interfering with that tooth, eruptive pattern. And it’s important to look at, you know, rather than, you know, kind of focusing in on, okay, well at this age, you know, we’re supposed to have these number of teeth and at this age, we’re not, but the differences in symmetry for these patients is going to be indicative of these developing problems. So we can have patients who I mean dentally are more like a nine year old instead of a 10 or 11 year old, but everything’s kind of developing along the same general pattern. They’re just a little bit delayed, and that’s fine. It’s when we see that unilateral deflection of a canine up, issues developing that we’re going to start thinking about a plan there. And the last thing I’ll mention before I turn it over to you for, you know, just some additional comments here. One of the things that I was hoping they would really catch that they didn’t catch when they were analyzing and discussing this, was that the difference that started to develop in terms of the angulation relative to the lateral and to the midline, in the teeth that were getting impacted. One of the, you know, even more significant differences, like in terms of magnitude, just in looking at some of the tables was the fact that when they become impacted, there is interference and interaction with that lateral incisor. So the change in the discrepancy between the angulation of the midline and the angulation of the lateral starts to kind of diverge at that point when you’re starting to see an impaction developing. So when we see things in or out of the line of occlusion, and then a really, really significant involvement of that lateral, that is going to be you know, two of the hallmarks that we’re going to be looking for on these 3D X-rays that we do.
William Hatcher 44:45
Yeah, I guess. Excuse my cough. I guess the biggest thing sometimes this can be challenging as a orthodontist is to sometimes see a 12 or 13 or 14 year old come in, and the impacted cuspid is, you know, nearing the midline palatally and gets to be a bit of a challenge. And so and sometimes there’s extenuating circumstances where, where the hygienist or the dentist is really recommending them to come see us and for whatever reason, it hasn’t happened. So, you know, I think early intervention and I think the 3D X-rays that we have, at our offices really make a big, big difference because then catching it early just makes such such a big difference and, and the amount of care that we have to do is so much less and less care for our patients means that they’ve had great experiences with us and with you and it really makes a big difference that way, Scott.
Scott Frey 45:46
Yep. Yeah, the and they touch on that as well, you know, as they’re kind of unpacking, you know, how they’re finding stackup with other papers. Obviously, they’re aware of what these 2D papers have found in the past, and what they’re finding in 3D and how it’s, you know, markedly different and it’s much more level of detail that they’re able to kind of capture, but their study was unique in terms of they knew that these teeth, were going to be destined for impaction it wasn’t, you know, you know, something that, you know, they they didn’t we weren’t able to do it in some of these other studies. So they made a specific distinction between impacted and non impacted teeth and they followed it all the way out. And then also obviously, the fact that it was three dimensional was super important. I’d love to get in you know, we had prepared a couple things just to kind of bring this back around to you know, basically real world examples, and what you would see or we would see in practice here, so, you know, we typically will want to get panoramic X rays to evaluate for canine impaction ages seven and up. So right in that sweet spot between kind of 7 and 10 is when we want to start looking and tracking these canines just to make sure they’re not getting loose somewhere driving on their neighbor’s lawn, all that good stuff.
Scott Frey 47:08
You can see this example here. This is somebody who came in and yes, there is crowding. Yes, there are things that we’re watching, but it’s not someone that we’re recommending anything at this time for. Mainly, because the angulation of both canines even with that, you know, bit of overlap on that right canine there in the maxilla. We’re going to be watching this with, you know, basically every 6 or 12 months somewhere in that time range to kind of check in and make sure that these teeth are kind of zipping down where they’re supposed to be. We do see on the lower that there is, you know, some significant crowding. You know, certainly we can be proactive and have that one primary tooth wiggle down. But in this particular circumstance, you can see that there is some resorption of that, that lower canine so we’re just going to watch that for right now. You know, if the parent raises a concern about that tooth and they seem particularly motivated to kind of, you know, be proactive, you know, yeah, we can put that on the list of things to treat. But when someone comes in like this, we see the angulations. We see that there’s really not a huge cause for concern but there is future orthodontic needs. We’re not going to jump in and do anything, but we will kind of do some watchful waiting.
William Hatcher 48:29
And, Scott, on that previous pan down there on the lower left lateral incisor a lot of times and maybe it’s just anecdotally for me, whenever I see those lower lateral incisors where the distals are kind of turned buccal, typically there’s plenty of room for those customers to come in and really do a decent job. It’s crowded, but it doesn’t necessarily warrant treatment. So just keep an eye on that as you go through looking at everything.
Scott Frey 48:55
Yeah, and that’s, I think, you know, these things. I hope this is going to help, you know, our dental friends listening here to kind of analyze and evaluate their own imaging when they kind of see things developing in their patients so Yeah, that’s absolutely right. It’s almost like the ugly duckling just for the lower arch. You know what I mean? Like it’s got that, that appearance there, helping guide that tooth in but not blocking this one. You can see it’s in Sector three; basically, it’s way over there. The lateral route has been reserved, which is interesting, right? Because they, you know, originally thought, hey, you know, lateral incisors are I mean, primary canines, not resorbing is why it gets tucked in behind the lateral incisor. But in this circumstance, you can see it’s kind of resorbed it, but it’s also stuck. But this one is, I mean, we’ll get the primary canine out and start making room because the patient’s ready to get started. But I like our chances of getting this tooth in without having to do surgery, don’t you?
William Hatcher 49:57
Yes, sir. Absolutely.
Scott Frey 50:00
Yeah, it’s, I mean, this is it’s a little bit late, you know, we would have loved to have seen it a little bit sooner. But, and that tooth may, you know, we could have directed it all the way in even without some orthodontic treatment, but at this stage, it’s recoverable. So we’re not going to, you know, sweat too much there. But that one. Here’s another example, and this gets into the local obstruction involving lateral incisors. Okay.
Scott Frey 50:28
So this patient, you know, lateral incisors are going to come in, you know, somewhere between 7 and 8 typically, you know, they can be delayed a little, you know, ahead of schedule sometimes, but when you get up there and age with this patient, and you can see that we’ve got, you know, good development of lateral incisor routes, as you can see here, but there’s just simply no room for them to come in. That’s where we go ahead and get concerned about what they’re going to be doing. And you can see, they’re already starting to kind of tip and entangle themselves with those maxillary canines, on the lower right and lower left to some degree. There’s almost no space for the lower permanent canines to kind of park themselves in the arch. And, you know, this patient, you know, probably had some crowding. As those lateral incisors come in, it starts to wiggle out some of the primary canines and then all of that space is stolen and lost by the incisor liability, and now there’s just simply no room for the canines so this is someone who got to us, you know, just the right time, because yes, we are going to need to make some space. We will not need to necessarily take out any primary teeth. But if we facilitate normal developments, and get that back on track, we’ve got a very, very good shot. I mean, pretty close like 100% that we’re not going to have to take out any primary teeth, have to do any surgical exposures because the canines are going to be funneled into the correct area. And we’re going to have gotten things back on track. Do you have any comments at all?
William Hatcher 52:03
Yes, sir. Our experience is you know, as they say If you build it, they shall come all the words if you create the space, they will come and I know there was a studies years ago, where they made the space, you know, by one and a half teeth and they really found out that those canines a lot of times, once you get those obstructions out of the way, they come down on their own, whether they come down in the timely fashion of your senior year in high school and college or not, may help dictate whether you need to get it exposed or apically repositioned to that to that manner to help everything nice. But if we create a space, chances are good things are going to happen.
Scott Frey 52:44
Yep. And that’s, I mean, it’s funny because a lot of parents, you know, they’ll come in, they’re not familiar with that ugly duckling phase and stuff like that, you know, they think that the shifting is super concerning, and it’s our job to look at that and say, Hey, this is fine. You know, certainly, they’re going to be shifted, but we have the actual space, and these teeth are going to come in in the correct spots. So you know, making sure that there’s sufficient room, looking at the angulations, looking at the position of these teeth like we’re doing with these early screenings. Super key and getting them into the mouth.
Scott Frey 53:16
Now, what happens when we encounter a situation where, you know, we have to do the surgical exposure, and we’ll kind of go through this one case example here.
And you can see, she was about 15-16 at the time of these initial records. Obviously, with the primary canines in place, that’s a bit of concern. You know, she does have some spacing on the top. But the permanent canines are pretty good and stuck. And you can see here, you know, basically what is it, sector four all the way back over there, interacting with almost the central incisor at this point. And we’ve got pretty full retained full rooted retained primary canines in the upper and we’ve got some really excellent surgeons around here. That will do exposures for us. In the way that we, and you know I mean, Dr. Becker, like, kind of lays it all out in his literature, extensive analysis that he goes into his book about how to get teeth in in a proper way. And the open exposure technique for a palatally impacted canine is the most physiologic way of directing these teeth into the mouth. You know, the oral surgeons got to obviously uncover, access these teeth, place a little bit of barricade, you know, or period pack or something over that particular location. And then we’re going to have a really clean path to bring that tooth into the mouth. And that saves us you know, a ton of time, you know, for somebody like this, I mean, what would you say you know, as the average, you know, treatment time that someone’s going to, you know, be in braces or aligners before we get these?
William Hatcher 55:04
Well, Scott, I think there’s two ways to look at it. If you looked at me, probably my first 10-15 years of doing this, I would always make it 24 months, and then I would always add six months to that time because then we’re probably doing a few more braces at the time. And we’re always trained and taught to create the space form before we go get the exposure done. And that typically will always add extra time. Now, with the advent of Invisalign, and also now that we do it with braces, well, we get the exposures done, hopefully within the first month or two of starting our appliances, whether it’s going to be braces or Invisalign, and we’re able to start bringing those cuspids in with the open exposure so much more rapidly and when it’s an open exposure I feel like to surgeons are even more methodical as far as removing some of the bone around the crown of the tooth. So we’re less likely to have to have pressure necrosis to bring them in which can be very uncomfortable and take a lot longer. So with the advent of the open exposures that we do routinely, the crown is typically a little bit more exposed, we’re less likely to have gingival issues and bony tissue, so I’d say 18-20 months, we can get this done looking good. And if we have a patient that’s game on, could be even a little less than that.
Scott Frey 56:27
Yeah, I mean, that’s a, you know, the reason I, you know, wanted you to get into that is the way in which we’re exposing these now, I think, is a huge, huge time saver. You know, certainly the old way with that chain going through the tissue. It’s basically necrosis of overlying bone and dragging that to through, and it’s uncomfortable every time we have to activate it for the patient. The open technique has a clear path: the tooth is in, the discomfort related to the surgery subsides quickly after that, and then the tooth is just coming on in. We’re directing an end; more importantly, it saves the patient a ton of time and inconvenience compared to that closed technique. Now, certain times, you know, given the location of the tooth, they can’t do the open technique all the time, but it is, you know, the skilled surgeons that we have here, you know, they’re very, very capable of doing that for most of the cases.
Scott Frey: 57:30
You can see with this patient she did, actually, didn’t get braces. She got Invisalign. And you know, some people will say, hey, you can’t bring it impacted teeth, and that’s simply not true. She had no braces that were placed on; we were able to get these teeth in, you know, there’s stuff that we do in the background like, you know, and part of the knack that we have for, you know, using you know, both clear aligners and brackets makes it a lot more convenient and pleasurable for the patient because we can sidestep some of these difficulties with that people would experience with other techniques. We could go ahead and get these in, parked where they needed to be all in 20 months, and no braces were used. There’s a little bit of space around that smaller right lateral incisor where the tooth size discrepancy is significant, but you know the occlusion is exactly where it needs to be; the tissue looks awesome around those. Can you comment a little bit? Because the open technique you can see and it’s been studied, it’s definitely better than the clothes regarding tissue aesthetics.
William Hatcher 58:39
Well, Scott is, as you look at them, I found that as we do the open exposures, hygiene is so much better. In the close exposures, we were always pushing and pulling on the chain with elastic thread or what have you. And so that area was always a little sore, and the patients inadvertently said, Well, if it’s sore, I’m going to brush it less. And then the inflammation was there. And then it was a real challenge. And when you finally got it in and took a look at everything, the gingival tissues were just so inflamed, and then you’re going to get a bunch of hypo calcification. So with the advent of open exposure and doing the Invisalign, hygiene for me is along with being done sooner, and of course, the sooner you get done, always better the hygiene. So those who go together significantly are the biggest advantages I’ve seen, with the combination of Invisalign in the open exposure.
Scott Frey 59:37
Hour of technology making things easier. Thank you, everyone, for joining us for this kickoff episode. I hope it was informative. I hope you get your CEs, so make sure that you click the quiz link at the bottom, get your information filled out, and get that completed so we can get you your continuing education credits. But if there’s any topic that you want to hear about, we’ve got some other ones planned throughout the year here. Some guest experts are coming on. I talk about some fascinating subject matter, you know, in a couple of months here, but if you have anything that you want us to cover, do not, you know, be shy, reach out to our team and our office and let us know what you want to hear about. But thank you.
William Hatcher 1:00:23
Hey Scott, one last thing: a shout-out to Stephanie, who keeps our CE current and up to date. That can be very daunting, and we’re very appreciative of her work. I’m sure you’ll see her run around the different offices and visiting and saying hi, but if you do tell her, Tell her we threw her some love and a big bone because she does a great job. So let’s take care of everybody. Take care. Bye bye.