Orthodontic Products Chief Editor Alison Werner speaks to Dr Jeffrey Miller about why CBCT is key to the long-term stability of orthodontic cases. Miller, who is a frequent lecturer on the topic and is in private practice in Maryland, explains why cone beam computer tomography should be a part of an orthodontist’s treatment planning workflow and why keeping the individual tooth root within the alveolar housing should be a primary treatment consideration.

Miller shares how he incorporates CBCT into his workflow and offers advice to orthodontists looking to purchase a CBCT machine. What’s more, Miller talks about why CBCT is so vital to orthodontics maintaining its status as a specialty. OP


Alison Werner: Hello, my name is Alison Werner, and I am the chief editor of Orthodontic Products. Thank you for joining us today. Today we’re going to talk to Dr. Jeffrey Miller about the role of CBCT in the orthodontic practice. One of the arguments against direct-to-consumer aligner companies is centered on how they’re putting patients at risk for complications or poor treatment, because they’re performing aligner treatment without proper imaging. But the reality is orthodontists may also be putting their patients at risk for long-term complications for similar reasons.

The fact is today’s imaging technology can give orthodontists a more complete picture of the patient’s alveolar bone anatomy. And with this information, they may improve the long-term consequences of orthodontic treatment. As I said, we are talking to Dr. Jeffrey Miller today, an orthodontist in private practice in Baltimore, Maryland, who frequently lectures on cone beam computed tomography, or CBCT technology in orthodontics. We wanted to talk to him about what CBCT imaging brings to orthodontic treatment planning and treatment outcomes. Dr. Miller, thank you for joining me today.

Dr. Jeffrey Miller: Thank you so much for having me.

Alison Werner: Great. Well, let’s get started. How does CBCT imaging improve orthodontic treatment as well as change the way orthodontic treatments results are evaluated?

Dr. Jeffrey Miller: There’s many uses for cone beam CT, but for orthodontists specifically, it has to do with a shift from using cephalometric analysis where we’re taking a two dimensional x-ray and trying to measure relationships between the teeth and the bone that support it. With cone beam CT, orthodontists for the first time are actually able to visualize the position of the root within the alveolar housing for individual tooth. What that also means is that when the cases are completed orthodontically, we can look back and see if we were able as orthodontists to keep that tooth within the alveolar housing, or if the tooth is pushed out or expanded outside of the alveolar housing, and it dehisces through the cortical plate.

What does that mean? And what does that look like? And does it really matter? I think the argument that if you use certain magical appliances orthodontically that you can expand, and there are no consequences because the bone modifies as the tooth or the root is expanded. I think that’s pretty much been put to bed that does not happen. There’s many studies, they all point in exactly the same direction. I am aware that they’re still orthodontists making those claims. I would just in my humble opinion that they should be looking at the literature and not at the information that’s provided by the manufacturer of those orthodontic systems.

Alison Werner: Okay, well, a greater percentage of orthodontic practices are using 2D cephalometric imaging than CBCT. There are those orthodontists who think this cephalometric analysis gives them all that they need for treatment planning and tracking outcomes, but what are they missing?

Dr. Jeffrey Miller: When you look at a two dimensional ceph, and they’re usually using a combination of a cephalometric x-ray and a panorex. They’re looking at those two images to treatment plan or help them treatment plan orthodontic case. But what they’re missing is they’re missing that they can’t visualize properly what the alveolar anatomy is for individual tooth. The alveolar anatomy or the alveolar housing that supports that tooth not only varies between different individuals. It actually varies in different segments of the same individual’s arch. And there is no way to look at that and evaluate it with a ceph and pan. It’s just too limited. So why so few orthodontists use a cone beam currently? I think it’s actually sad because here we have a tool that allows us I believe, a much more detailed way of treating these patients and evaluating their finished results, but there’s a tendency to want to hold on to what you’re comfortable with. And also, when you look at cone beam, it’s also a matter of knowing how to use it.

A lot of orthodontists that actually have cone beam, they’re using it for other things. They’re maybe looking at the temporomandibular joint, and that’s why they have the cone beam machine, or they’re looking at airway, which I’m not sure is really a valid use for cone beam. But what they tend to do is take the cone beam and reconstruct the pan and ceph from the cone beam. And even though they’re taking cone beam, they’re still using the same cephalometric analysis, where the real difference is that when you start looking at individual teeth and alveolar housing, it really does change everything for you orthodontically, not only in the way you treatment plan the cases, but the way you evaluate your finished results.
For example, if you have a case where you’re not sure, you think it’s a borderline extraction case, and you are just trying to decide, is the best thing for this patient to extract four teeth? To expand? To do interproximal reduction? You can finish that case in any of those three treatment strategies, and clinically, the case is going to look good. The clinical crowns of those teeth are going to be aligned and you may think you did a really good job, but when you look at it from the perspective of a cone beam CT versus a pan and ceph post-treatment, you may realize that, “Oh, I expanded this hit, but these cuspid roots are halfway out of the alveolar housing.

That information will help you for the next case you treat. So the next case you see, you’ll say, “Well, wait a second. Let me rethink this. Maybe there’s a better way to do it. Maybe I should do a little more IPR.” And this is not an argument about extraction versus non extraction, it’s an argument to what is the best way to keep the teeth within the alveolar housing when you do orthodontic treatment. I believe it’s a gold standard because I don’t think anybody’s going to disagree that a healthier tooth is one that the root is completely surrounded by bone. And once you minimize or compromise that bone support, that tooth is not as healthy as it was when it was surrounded by bone. Now we can at least visualize it.

By the way, orthodontists are some of the smartest people on the planet, and they come up with these rationalizations as to why cone beam’s not necessary. And they come in different forms, but basically it’s, “There might be 0.6 millimeters bone missing. It shows as missing on the cone beam, but it actually might be there.” And they’ll also say, “Well, dehiscence and fenestration are present in most of the population, and cone beam CT studies show that there’s a lot of false positives.” When in other words, on the cone beam it looks like a dehiscence, and there is actually bone there. But those things are, if you really think about them, they’re really pretty meaningless for orthodontists because the dehiscence studies are all done on naturally occurring dehiscence that are very minor.

So orthodontically, we make an effort to keep the teeth within the alveolar housing. If you violate that a little bit, I’m not sure it really affects the long-term health of the tooth. What we’re talking about is orthodontics that causes the root to go halfway out of the alveolar housing, that’s a significant magnitude. And orthodontists are putting these things in the same category where it’s a big difference between an orthodontically induced dehiscence, where the root is significantly out of the alveolar housing and one that just slightly is.

And these are the arguments that are being projected today. The 0.6 millimeters of non visible bone on the cone beam CT is actually plus or minus 0.6 millimeters, they tend to forget that. But there’s a process or rationalization that I hear quite often that anytime you see a root dehiscence on a cone beam, it always has 0.6 millimeters of bone there. And that’s not at all what those studies show. It’s a total abomination of that information, but I guess it’s a rationalization when you see it post-treatment. And when you see the dehiscence and you don’t do anything about it, it’s not going to help you for the next 150 cases you treat. You got to recognize it first. And we finally are able to have a tool where we can do this, and it does change things, orthodontically.

Alison Werner: Yeah, definitely. Okay. So you talked a little bit about some of the risks of not using cone beam CT imaging as part of treatment planning. Can you talk about anything else orthodontists should be recognizing by not using this technology?

Dr. Jeffrey Miller: Well, the big one is they won’t be able to recognize, there’s two things. One is the treatment diagnosis that goes on that determines the treatment strategy that’s appropriate for that individual patient. And then also, the finished result, how do you evaluate a finished result? There’s lots of finished results orthodontically that clinically look fantastic because you’re only evaluating those cases based on the clinical crowns. It’s almost like with Invisalign, the virtual setups all look perfect. The tissue always looks perfect, but the tissue has no basis in reality, the tissue is painted on those virtual setups by a technician. So you can expand and the tissue still looks fine, well, it’s the same thing that happens clinically. The tissue response to the dehiscence and fenestration is a lagger.

It doesn’t happen immediately, usually. It was a function also of the gingival phenotype or hygiene, and health of the patient. But in general, it won’t appear right away. I mean, there’s plenty of cases out there where there’s no question the root was mostly pushed out of the bone, and the tissue is almost like a stretch rubber band around the anatomy of that root, but the tissue response, which is a loss of tissue, which is gingival recession or gingival dehiscence hasn’t occurred yet. It’s also a long-term perspective and these things still need to be studied because I believe the literature pretty much is clear that if you orthodontically move the tooth through the alveolar housing, you’re going to create root dehiscence or fenestration. But what’s not exactly clear is how does that affect the tissue? So someone with a thicker gingival phenotype may be able to get away with more root dehiscence than someone with a thinner gingival phenotype. And these are things that it seems you can draw conclusions, but I don’t believe they’ve been really properly studied.

Alison Werner: Okay. We talked earlier, and one of the things you mentioned was that by not using cone beam CT to monitor and to also check those finishes, down the road, orthodontists could be putting themselves at risk if another dental provider examines them and sees undesirable consequences of the orthodontry. Can you talk a little bit about that?

Dr. Jeffrey Miller: Yeah. Orthodontists, we don’t practice in a vacuum. Our patients are usually shared patients with other dental providers. So when we treat a case, and we take a post-treatment ceph or pan to look at our finish, the general dentist is generally not going to take a pan and ceph just to look at the result of the orthodontic treatment. But as cone beam CTs become less expensive, the Delta or the difference in price between a digital pan and a cone beam CT is smaller. The gap is much, much smaller considering that the fee, the general dentist gets for a cone beam versus a pan is significantly higher. When that general dentist, and it could be any dentist, I’m just using a general dentist as an example, when that general dentist needs to replace his pan machine, is he or she going to replace it with a cone beam CT or another digital pan, which is becoming outdated.

And I think if you talk to the general dentist, when they’re looking for a new machine, they’re looking in the direction of a cone beam CT, because the cost is really not that much and they can generate higher fees. So that patient that was treated today by an orthodontist where the roots were violated or dehisced through the cortical plates, that patient then five years from now goes to their general dentist, and that general dentist takes a cone beam CT, versus the pan they take every two or three years. When they look at that cone beam, the pattern of dehiscence, the generalized pattern of dehiscence that occurs from orthodontic treatment or poor orthodontic treatment is very obvious. So then what does the dentist do? Does the dentist ignore it completely? I don’t think so. I mean, the general dentists are more than happy to criticize the orthodontist as it is today, I mean, for stuff we’re not even guilty of.

Here’s something we are guilty of. These general dentists are going to look at these cone beams and go, “Oh my God, the roots from your lower first bicuspid, it looked like they’re dehisced through the cortical plate. Let me send this over to an oral and maxillofacial radiologist to read.” The report’s going to come back, and the radiologist’s going to say, “Two thirds of bone is missing on the buckle surface.” Even in the absence of tissue dehiscence, what’s that dentist’s obligation to that patient? My guess is they’re going to make a referral to a periodontist. So if you think about it, five years from now, the cases you treat today even in the absence of tissue dehiscence are going to be evaluated with a cone beam at some point in the next 10 years most likely.

If there is tissue dehiscence, the general dentists are going to take a cone beam and say, “Well, your root’s sticking out. That wasn’t there before.” So the idea that they were brushing too hard and they did it to themselves, orthodontists, I mean, I believe we contribute to it. I think there is documentation that shows clearly that orthodontics is related to an increased incidence of gingival recession. Now, the same argument happens with that as well in the orthodontic community. There’s studies that show as you get older, gingival tissue recedes.

But when you talk about gingival recession related orthodontic root dehiscence, you’re talking about gingival recession of a much higher level. It’s a higher magnitude, and it happens sooner on a younger population. We tend to put all these things in one category and I believe it’s just a rationalization, but they don’t fit in all one category. It’s just like saying, “I smoked a cigarette once when I was 14, and I am at the same health risk as someone that smokes four packs a day for 40 years.” There a difference in the magnitude of these problems that are associated with these types of treatment.

Alison Werner: You talked a little bit about this, but one of the arguments against cone beam CT use is the risk of false positives associated with dehiscence and fenestration. Are the false positives really as common as some believe? And how does this impact the use of cone beam CT for orthodontic patients?

Dr. Jeffrey Miller: It is true. The false positives are quite common, but the false positives are mostly related to minimal root dehiscence. So it goes together with the possible plus or minus 0.6 millimeters of bone that may not be visible. So when you have a tooth like a prominent cuspid, you’re going to see along that facial surface, on a cone beam you might see a very thin thread of bone on the axial view. Is there a bone there, or is it just slightly dehisced? Well, it could be slightly dehisced, but I don’t think that really matters in terms of orthodontics other than if you have a slightly dehisced root or very, very thin bone let’s say on the facials aspects of the lower cuspid roots. If it’s pre-treatment what that tells you is you probably don’t want to expand anymore because whether there’s 0.6 millimeters of bone there, or maybe there’s a slight dehiscence, or there’s no dehiscence, there’s thin bone.

So if you expand, there’s not a whole lot of bone to move that tooth. Now, if it’s after treatment, if you take a post-treatment cone beam CT, and you see a bit bone that looks like it slightly disappears, and I’m not sure it means anything clinically, but when you see the root that’s one third or halfway out of the bone, post-treatment, then you might want to reconsider your treatment strategy for the next case that’s like that. So I believe it’s more of a rationalization, the studies that are done on false positives using cone beam CT for dehiscence, they’re most all done on or they are all done on nationally occurring dehiscence, and naturally occurring dehiscence are quite different mainly in magnitude to dehiscence that is orthodontically induced.
We talk about orthodontically induced dehiscence, we’re talking about just the roots halfway out or a third of the way out. That’s a big difference from something that just… You have to look at it. And by the way, the studies on this topic, when there is a significant root dehiscence, it’s very easily recognized on the cone beam, and there are not false positives when it comes to that. The false positives are related to minimal or minor dehiscence.

Alison Werner: Okay. Great. Well, so how do orthodontists avoid dehiscence then? Let’s talk about that.

Dr. Jeffrey Miller: I don’t believe we can actually avoid it completely. I think it’s just part of what we do. I think a realistic objective for treatment planning orthodontic cases is to minimize it at best. And clearly, patients can get away with a little bit of root dehiscence. Otherwise, orthodontic patients should be losing teeth left and right. I think it comes down to proper treatment planning. So there are different treatment strategies. For example, if you are a non extractionist, complete non extractionist, there’s not many orthodontists that will say, “I never ever extract a tooth,” but there are some that lean the pendulums towards a non- extraction side, which means if you have a crowded case, you’re expanding. So if you expand and you take a pan and a ceph post-treatment, and look at your results, and you’re measuring things like the changes in the lower incisor to the mandibular plane angle, you’re probably not going to get that much of a change.

But when you look at the cuspids, which you can’t evaluate changes radiographically to the cuspids. The only thing you can do is clinically evaluate the change of the intercuspid width. But with cone beam, you can actually look at the position of the root cuspids, and this is usually where the roots get dehisced the most, because a lot of times especially with the broader Form arch wires, they expand the lateral segments, which means they’re expanding the cuspids and the first bis, and those changes cannot be measured on a pan and a ceph. So you expand, and then you take a pan and a ceph to evaluate your finished result. You do the cephalometric analysis and you go, “Wow. I did a great job on this case. Look, the lower incisor to mandibular plane angle only changed two degrees from what it started with.”

But that’s not where the decrowding really came. The decrowding was associated with the changes in intercuspid width. By the way, there is probably no greater body of refereed scientific literature in orthodontics than changes in the lower intercuspid width. Basically, that literature points in one direction and that is the more you change it, the less stable long-term that case is. So what’s happened in orthodontics in my opinion, is that as orthodontists, as a group, we went through a large discussion about long-term stability of treatment. And we’ve gotten away from that discussion completely, mainly I think because bonded fixed retainers allowed for us to break all the rules of orthodontics and get away with it, at least in the short-term. So we’ve gotten away from this discussion about what’s going to be most stable long-term, to this idea that, “Well, I like my bicuspid. It’s a little more upright because I think it’s more cosmetic.” And to me, it’s just a bunch of rationalizations for really poor orthodontic treatment.

It’s almost as if these orthodontists, they’re only concerned with the clinical crown. So you started this interview with the direct-to-consumer products that don’t take x-rays, and there’s no doctor to supervise it, and then you led into that and you implied that there are orthodontists doing the same thing. And I think that is really a problem because as orthodontists, we really need to clean our own house. I mean, I go through some of these Facebook groups, and I look at the cases that are posted on there. And these are cases that I look at, and I just can’t believe it. To me, they’re gross negligence, and that’s putting it nicely. And these people are posting these cases, and they’re proud of it. And then other orthodontists chime in and they go, “Oh, great job.”

But they’re great cases if you’re evaluating results based on the clinical crown alignment. They’ve reduced orthodontics to the mechanical alignment of the clinical crowns. It’s clear from those cases that these orthodontists that are posting, they’re not even mindful what’s going on below the gingiva, or below the CEJ, because if they were, and it’s surprising to me, a lot of these orthodontists actually have cone beam. I was like, “What are they even doing with it?” I mean, if they would look at it properly and do a proper evaluation on that cone beam, they probably need to change their underwear because it would not be pretty. I’ve seen so many cases that this, I mean, it’s not like it’s an outlier. I see them all the time. People come in here, and I’m like, “Let me take the cone beam.”

They’re like, “Oh my gosh.” What do you do now? And also, there’s a perception in orthodontics, I just mentioned this, that if I’m going to try to line everything thing up, I’m going to expand. I’m going to see what it looks like, and then I’ll decide later whether I need to extract teeth or not. It’s really not good treatment planning because what happens especially in the lower anterior region, when you do that, the alveolar housing that you had adaptively resorbs to comport with the position of the artificially expanded teeth. And then when you say, “Well, this is not working out. Let me pull teeth and move the teeth back into the alveolar housing, the alveolar housing that was there when they started treatment is smaller than what it is after you try this treatment strategy.

Like I said before, it’s not about whether you extract or expand. It’s about trying the best strategy for the patient that keeps the root of the tooth centered within the alveolar housing as best as possible. Some orthodontists will go a step further, and they’ll add bone pre-treatment so that they expand the alveolar housing, but I think for the majority of cases, a good treatment strategy orthodontically can still keep the tooth reasonably within alveolar housing. I think one thing cone beam tells you is probably what not to do. It may not tell you exactly what to do, but it will tell you, “This is not a good plan for this patient,” especially when you look at different types of alveolar housings, and I can show you a slide of the… When you look at cone beam, one of the things you really become mindful of is that the alveolar housings are different sizes and shapes.

I mean, what are you supposed to do as an orthodontist? Are you supposed to just ignore that information? I mean, that doesn’t even make sense, but that’s what’s happening because cephalometric analysis assumes that all the alveolar housings are approximately the same size and shape. There’s really not a measurement on cephalometrics for the most part that looks at the anatomy of the alveolar housing. And with cone beam, you see it. So you can look at it and you go, “Whoa, this dolichocephalic patient has a golf tee looking alveolar housing. Do I want to expand this case?” I mean, I have it in my slide deck here. Slide deck’s an old term, PowerPoint. But it’s a dolichocephalic patient that was, I mean, expanded beyond belief.
The tissue’s all blanched. There’s no question that those roots are out of the bone without even looking at cone beam. And they posted up on one of the Facebook groups, and nobody said anything bad which is commendable, but a lot of people were complimenting the case. “Oh, Great job.” But then you saw some comments, they don’t want to openly criticize, but they’ll say something like, “Well, what about the tissue recession that wasn’t there that’s associated with these several teeth? What about the tissue blanching?” So these orthodontists, not that they should be jumping on this case and saying how terrible it is, but to learn something you have to recognize it. And to show a ceph is going to show you a successful case. To show a cone beam will show you a case that’s actually a disaster.

Alison Werner: Okay. How are you using CBCT in your practice? How does it fit into your clinical workflow and your treatment planning?

Dr. Jeffrey Miller: Okay. It’s a good question because it does change things. So our diagnostic records, we don’t take cephs anymore. The original cone beam machines we have have a ceph attachment. We don’t use it anymore. There’s no reason to buy that ceph attachment because you can reconstruct a cephalometric x-ray from the cone beam 3D reconstruction very quickly, just like you can reconstruct the panorex. So we take a cone beam on all our patients. The argument about a high dose radiation or you’re exposing younger children to a higher dose of radiation, really it doesn’t hold any water anymore because the new machines it’s actually about equivalent or maybe a little bit less to take a low dose cone beam versus a pan and ceph. And that’s a digital pan and ceph. I mean, I can’t imagine someone’s still practicing with a plain film, but the radiation levels of those are higher.

So that argument about increased radiation doesn’t really hold water anymore. Even the low dose cone beams, I mean, they probably wouldn’t be good for an endodontist, but they’re absolutely fine for orthodontist, in my opinion. Because we’re looking at individual teeth and the anatomy of the alveolar housing that’s associated with that tooth. And from that, we develop a treatment strategy that best keeps those roots within the alveolar housing. Like I said before, and I like to repeat this, to think that you’re never going to dehisce at all is not realistic as an orthodontist. It’s just try to keep it to a minimum. I mean, sometimes you have a rotated lower incisor and the buccal lingual width on lower incisor it’s generally wider than the mesiodistal width. So if a tooth is rotated 90 degrees, and then you turn it to correct it, lower it, there’s a good chance that there won’t be enough alveolar housing to hold that root.

So if that patient doesn’t want to get a bone graft pre orthodontic treatment, they take their chances. And we hope their tissues quality is good enough that at least you don’t see the tissue dehiscence while they’re in treatment. And then later you can blame it on a toothbrushing trauma or something. So what we do is we take cone beam on every patient, and we try to come up with a treatment strategy that keeps those teeth within the alveolar housing as best as possible. Let’s say, it’s an example, it’s a patient with 12 millimeters of crowding. Well, I don’t think with 12 millimeters of crowding in the lower arch there’s any reasonable orthodontist that thinks that they can expand that arch and not run those roots through the alveolar housing. Well, let me take that back.

If you’re an orthodontist and you believe that you’re using some magical system that modifies bone as you expand, show me the data that supports that, because it doesn’t exist. Okay. Other than from the manufacturers. That’s probably not a good strategy because when you look at the post-treatment results cone beam wise, you’re going to be upset, and it’s not a good thing for the patient. In those cases, sometimes even an extraction doesn’t give you enough space. You have to extract, and then you have to shave a little bit, but that would be one category. And let’s say a patient comes in with generalized spacing, where you have to close the space. Well, depending on their alveolar housing, you might not be able to close all the space. So in a case like with a bimaxillary protrusive patient that comes in with generalized spacing and tongue thrust, the alveolar housing projection, I can show you this in an image, comports with the position of that tooth.

And on those cases, uprighting the lower incisors will probably do quite a bit of damage long-term. Plus it’s unstable. So it might be better to maybe not close all the space or leave space for a fifth incisor if the overject can tolerate it. Things like that change what we do as an orthodontist. And it really makes you rethink everything. I joke around with my colleagues. I’ve been so busy going around speaking, and I’m like, “Why would anybody want to hear what I have to say? I’m telling everybody everything they’re doing is wrong.” There’s a group I’m sure, they listen to what I have to say and they think about it, and then they come back with some rationalizations to discount the information so they can continue doing what they were doing.
And other people, they clearly get it. I get a lot of love. Actually, it’s very rewarding to me. I get emails all the time and especially from more experienced orthodontists. They go, “I thought about this for years.” And I think what it is, is I remember when I was a resident, getting off on a tangent here, but when I was a resident, our chairman, Dr [Kurnanov], blessed memory used to say, “A pendulum never swings to the middle.” It goes from extraction to a non extraction, and it doesn’t stop in the middle. So I think, we as orthodontists, we always are trying to figure out the best treatment for our patients.
And unfortunately, when you’re an orthodontist, after about 10 minutes of practice, you realize that parents don’t want to hear, “Extractions.” Nobody likes to lose body parts. I’ve heard orthodontists tell me, and I’ve heard it more than a few times, “Well, the mom didn’t want extractions on the kid, and even though there’s 10 millimeters of lower crowding, I’m just doing what the mom said.” You’re the doctor. Let that patient go somewhere else. That is not a good thing long-term. You can’t tell people what they want to hear and expect that to end well. You do what you know is right. You were trained properly. You went through all that school and to just come up with a, to me that’s a lame excuse. The mom didn’t want extraction so therefore I blew all the roots out of the cortical plate because the mom told me so.

Unless the mom’s an orthodontist, then they wouldn’t come anyway. The other thing cone beam does, and I think this is a tremendous value for us as orthodontists is if we get the patient, let’s say in the late mixed dentition or middle mixed dentition, we can take a cone beam and look for potential issues in a 3D format. And that really reveals quite a bit of information. For instance, if there are canines that erupt into the roots of the lateral incisors, more on the upper arch than the lower arch, that can be completely avoided. What happens is the cuspid erupts into the root of say the lateral incisor and just wipes the root out. That can be completely avoided if it’s caught early. And also, if we can develop a treatment strategy that allows the tooth to erupt within the alveolar housing versus erupt ectopically, and then go back orthodontically and try to reposition the tooth back into the alveolar housing later. For example, ectopic cuspid that comes in out of the arch.

We know that ectopically erupted teeth do not have the same root bone coverage as a tooth that erupts within the center of the alveolar housing. The gold standard I would say, is for the tooth to erupt within the alveolar housing. And cone beam allows you to better come up with a strategy to allow that to happen, providing you see the patient early enough. I think that’s tremendous. I’m not aware of anybody that’s actually talking about these strategies today. I mean, I know there are people now going around talking about keeping the teeth in the alveolar housings and how important that is. We also have now technology that allows us to virtually treatment plan the cases using the bone modeling of the cone beam CT, which I think is tremendous. Although it’s not perfect, the bone modeling’s static. At least you can tell what not to do. When half the root’s sticking out of the bone, you maybe want to rethink a treatment strategy.

Alison Werner: Okay. What’s your advice to orthodontists considering a CBCT purchase?

Dr. Jeffrey Miller: Okay. First of all, the best advice I can give you is don’t buy the cephalometric attachment. You don’t need it. First of all, you can recreate the ceph and you can get a perfect ceph because you can line up the left and right side and superimpose them exactly. You don’t need the cephalometric attachment. That’s the first advice. The second advice I would give them is when you look at these machines, all these machines have gotten better. As they progress, the technology gets better, the image quality is better. It’s almost like analog TV versus a high definition TV. Okay. When you look and you’re comparing the different machines, don’t get caught up in the software that reproduces a ceph and a pan because as you mature into the cone beam CT world, those become less and less, and less, and less relevant.

You also need to find out the cost per year for the service agreement, the licensing agreement. Some of the cone beam machines have a very hefty yearly fee for their maintenance agreement. Some of them have zero fee. That’s very important in terms of the overall cost to you for the cone beam CT machine. I would say that any orthodontist that’s starting out today or building a new practice, I think would be foolish to purchase a digital pan and ceph when the difference in cost is really not significant at this point, and having the cone beam, I don’t see a downside to it other than you may not want to see what you see, some ignorance is bliss thing. But back in 1959 Steiner said the same thing about cephalometric analysis, the orthodontists were resistant to using cephalometrics, and he said something, there’s a quote, I can give it to you later.

He said, “They’re afraid to see what they say”. And I think it’s same thing with cone beam. There’s no argument that cone beam doesn’t provide more information. The argument goes in the way of, “Well, I don’t need cone beam to treat these cases because the ceph and pan are the standard of care, and that’s what I use. And I’m the best orthodontist in the world, so I don’t need to change anything.”

Alison Werner: How does cone beam move orthodontics back to the specialty arena? How does it go back to being what it was?

Dr. Jeffrey Miller: That’s a great question. I believe it is going to be the thing that projects orthodontics back into the specialty arena whether or not orthodontists participate in that movement or not. Of course, every orthodontist wants it back in the specialty arena, where of course, I believe as a specialist, it belongs. But what happens is several things. First of all, when you start looking at cases through cone beam, they become more complex. What do you do here? If you’re just looking at it from the basis of the clinical crown alignment, your world is much simpler. So it makes it more complex. Imagine for a second that the aligner companies would start showing cone beam CTS, part of their virtual treatment. Then you go to align the teeth, and you’re like, “Well, wait a second. These roots aren’t in the bone properly anymore.”

And by the way, there are companies that do that now for us. What we’re finding is that these dentists are questioning, “Wait a second. I thought I could just line these teeth up and expand everything, but now I’m looking at the cone beam version of the virtual simulation, and it doesn’t look so great.” So that’s happening now. Also, what’s happening is the literature is becoming much more clear as to what happens when you orthodontically dehisce the root through the cortical plate. When cone beam was new, first of all, people didn’t know how to evaluate it, but secondly, people weren’t mindful of it because they were using cone beam like a ceph and pan, they weren’t looking at individual teeth.

Now that orthodontists that are versed in cone beam are looking at individual teeth, they’re seeing the manifestations of, I would say, poor orthodontic treatment strategies. But that’s really not the main reason why it’s going to move back into the specialty arena. I think the main reason is because orthodontists do not practice in a vacuum. As I said before, our patients are shared with other dental professionals. So when that patient that we treated 5, 10, 15 years ago, goes to the periodontist, I mean, I don’t know a single periodontist that doesn’t take cone beams now on patients. A good number of general dentists have cone beam. And as the prices of cone beam machines decrease, when they go to replace their digital pan, they’re not going to get a digital pan. They’re going to get a cone beam.

So they’re going to take cone beams on their patients. They’re going to recognize orthodontic dehiscence pattern. I mean, it’s distinct. You’ve seen one, you’ve seen them all. It’s a generalized dehiscence pattern of a much higher magnitude. So that orthodontist that is coming up with all these rationalizations of why they don’t need to extract teeth because they’re modifying bone and things like that, when that patient ends up in another dentist’s office, whether it’s a periodontist or general dentist, and they take a cone beam, and they see that general pattern of root dehiscence, they’re going to know definitively that was caused by the orthodontic treatment.

So then what do you do? The point is the cases you treat today are going to be evaluated differently five to 10 years from now. So if you think about that, orthodontists, this is what we’ll do. We’ll pivot. Some of us will pivot faster, some will pivot later. The general dentist that are doing orthodontics, and most of them when they do it, they’re using aligners or they’re using some of those bracketing systems that are marketed directly to general dentists. I mean, most of the general dentists are, I would consider what’s called a clinical crown jockey. They only care about the mechanical alignment of the clinical crowns. That’s their metric for whether it’s treated successfully or not.

Those general dentists are going to take a cone beam on their patient at some point, or they’re going to end up in another general dentist’s office and that person’s going to take a cone beam, or they’re going to send them to periodontists, they’re going to take a cone beam. And they’re going to say, “Oh my gosh, look what I did.” Well, they’ll stop doing it because last thing they want is a lawsuit. And there are already lawsuits associated with orthodontic movement that pushes teeth out of the alveolar bone. Before cone beam you couldn’t really visualize as easily until the damage occurred. Now you can see it in advance of the tissue recession. And those things are all going to push orthodontics, in my humble opinion, back to the specialty arena. And I’m not criticizing the general dentist. I don’t want anybody get the wrong idea.

They know what they’re taught by the manufacturer of the aligners. So they think what they’re doing is appropriate until something comes along that shows them it’s not. If they get an implant from a oral surgeon and the implant is sticking out of the alveolar bone, they know there’s something wrong. Well, you think that any general dentist that looks at cone beam and sees the root outside of alveolar housing is going to say, “Oh my gosh, maybe I should rethink this.” And refer it out. Or, “I’m going to stop doing this. I don’t need this aggravation.” Or, “I don’t need to complicate my life.” And I think all those things are pushing, and you think about the volume of just the aligners that are being done today by non orthodontic specialists.
I know in my practice we do aligners, and there’re many times we have to pivot the treatment plan, we have to make adjustments, and I’m sure that’s with everybody. They’re not as easy as people think, “Oh, I’m going to give the plastic to them, and they’re going to take care of itself.” Nothing is ever that simple. It’s that vast volume of it, I think it’s going to implode, but that’s just my humble opinion.

Alison Werner: Great. Well, Dr. Miller, thank you so much for your time and taking the time to explain this to our viewers. In the meantime, to catch up with past episodes or check out the latest orthodontic industry news, visit our website, orthodonticproductsonline.com. Thank you.

Dr. Jeffrey Miller: Thank you so much.