Intro: Welcome to UAB MedCast, a continuing education podcast for medical professionals, providing knowledge that is moving medicine forward. Here's Melanie Cole.

Melanie Cole, MS (Host): Welcome to UAB MedCast. I'm Melanie Cole. And today, we have a panel for you with two UAB Medicine physicians as we highlight a comprehensive guide to subperiosteal dental implants. Joining me is Dr. Michael Kase, he's an Assistant Director of the Advanced Education in Maxillofacial Prosthodontics and Dental Oncology Fellowship; and Dr. Jay Ponto. He's an Oral and Maxillofacial surgeon, both with UAB Medicine. Doctors, thank you so much for joining us today. And Dr. Kase, I'd like to start with you. What are subperiosteal dental implants? And how do they differ from traditional dental implants that we've heard about?

Dr Mike Kase: Sure. Well, thanks for having us again. I always enjoy coming on this program with you. But subperiosteal implant is a different type of implant than what people normally think of when we're talking about dental implants. So, the normal standard endosseous implant gets screwed, essentially, into the bone, whereas this subperiosteal implant sits on top of the bone, and it has a bunch of tiny little screws that's fixated to the bone. So, it almost acts like a cage as it sits around the bone and it has real good stability and allows us to put these implants in places that normal implants might not actually be able to go, which is very helpful for us. But as far as the surgical placement and maybe a little bit more specifics, I'm going to defer that to Dr. Ponto. He's the one that places them.

Dr. Jay Ponto: Yeah. So, thank you, Dr. Kase, and thank you for having me. It's a pleasure to be here today. Subperiosteal implants, as we're discussing them, are a new take on an old form of implant. In the 1980s and 1990s, they came out with these subperiosteal implants that were not really anchored to the bone like any implant that you think of today. And they didn't really work that well. But then, traditional dental implants came around, they screw into the bone and actually fused to the bone. So, they are intimately connected to the person, and that's great, but they have the disadvantage that they require a bed of bone to be engaged in and they take time to fuse to the bone, so you can't always function on them and chew immediately after getting a dental implant.

The subperiosteal implants, like what Dr. Kase said, are a cage that you put over the bone and they are mechanically retained to the bone. So, they are often used for replacing a stretch of teeth instead of, say, one individual tooth. And an advantage of them is that they can support the teeth immediately after being placed because there is no waiting period to fuse to the bone. Once you put in all the little screws and the implant is mechanically retained, we can often put teeth on immediately and give the patient a more immediate dental result.

Melanie Cole, MS: That's awesome. Really exciting in your fields, doctors. So Dr. Ponto, when would you consider these? For what patients are they ideal?

Dr. Jay Ponto: These are really good options for people who are not candidates for traditional dental implant therapy. So, patients who do not have that foundation of bone, like what I was talking about before, and it's all wide scope of patients that we have already performed this procedure on; patients who just congenitally were born where they have a very small jaw that doesn't have enough bone to accommodate dental implants, where we're worried about drilling into like a nerve or a sinus.

This  subperiosteal implant fits right on top of the bone and it has little screws that secure it. So, it's a very practical application for people with congenital problems. Also, if someone had a tumor removed, particularly benign tumors, and they have a stretch of missing teeth, then we can put this  subperiosteal implant in an area that they do have some bone either on their top or their lower jaw, and restore the teeth in that sense. It also works for people who may have had a large tumor removed and they have a hole that is connecting their mouth and either their sinus or their nose. When you have that hole, it becomes very problematic because you get food up into your nose, when you're eating, when you're drinking. Also, the resonance is much different in your voice, so it can serve to occlude those holes and correct those difficulties that patients are having when they're talking or when they're eating. This can be used after the fact in patients who later down the road have a missing stretch of teeth or one of those holes who had a malignant disease, but that's a little bit more tricky because we have to work around bone that's has often gotten exposure to radiation. It can be done in some situations. We just have to plan it carefully.

Dr Mike Kase: I'll also add that these are just great options for patients that just simply don't have enough bone too. So, there's another type of implant called a zygomatic implant, which we do, which is kind of a longer version of the regular implants we think of, but they're really only able to be used on the upper arch. But I personally think that this new option, the subperiosteal implant, offers a better prosthetic solution, and surgical solution for these patients. So, the versatility of these are just tremendous and really allow us to help patients where options weren't as great before. So, the strength in these is definitely the versatility.

Melanie Cole, MS: Dr. Kase, why do you prefer these over the zygomatic implants? You just mentioned those.

Dr Mike Kase: I'll be honest, a lot of it is personal experience. So, the thing about these zygomatic implants. In the right patient, they work fine. But the reason we have the zygomatic implant is because patients tend to not have a lot of maxillary bone, so they need to anchor these really long implants to the zygoma, which is essentially your upper cheek bone. And then, they have this about three inches or so in length and it just becomes this long lever arm that has this micromotion to it. And we've had it where those implants have fractured before on some patients where it causes a big problem in retrieval and the ability to offer prosthodontic solutions.

Tissue is often a concern as well. The tissue tends to be a little bit unhappy around some of these zygomatic implants that as they come out into the oral cavity and other reasons like that. So, they're very specific with what you can or cannot do. Whereas this subperiosteal implant allows you to do something that's fixed in place that doesn't come out, something that's removable. It allows you to do something that's unilateral. Whereas with zygomatic implants, you really cannot do something unilateral. So, again, the versatility, it just opens up all sorts of possibilities for the patient.

Dr. Jay Ponto: If I can add on too, another thing that's great about this, as opposed to zygomatic implants, is surgically it is a lot easier for us to place a  subperiosteal implant than a zygomatic implant, and it has more reliability when Dr. Kase is going to be restoring this. With a zygomatic implant, I have to place this long implant into the cheek bone and it goes into the mouth. And it's very technique-sensitive in terms of trying to get the exact location, and I need good exposure to avoid complications and running into other structures. Whereas with a subperiosteal implant, the patient gets a CT scan. We plan the subperiosteal implant with an engineer, and we make this implant custom just for the patient. And then, when we deliver it, my exposure is less dramatic and more reliable because, again, this is something that was just made custom for this person that makes it easier for Dr. Kase to restore because he was involved in the planning process, so we know exactly how everything is going to look after the operation is over. And it is a less invasive result.

Melanie Cole, MS: Dr. Ponto, along those lines, then, why don't you speak a little bit more about that planning and how these implants are made?

Dr. Jay Ponto: What happens is, for the workflow, patients come in for a consultation. And if they are an appropriate candidate, we can take a CT scan with some guides in their mouth that Dr. Kase makes. And the scan is reviewed by Dr. Kase, myself, and an engineer. And we plan this implant based on the patient's anatomy. The implant is made out of titanium, and it has some screws that are inserted into the cheekbone and on the sides of the nose. the entire surgery is done within the mouth. So, there are typically no scars that are left on the patient's face. The implants typically also have four what we call abutments or spokes that go from underneath the gum out into the mouth.

So when the patient wakes up, they had an incision in their mouth, but then they're left with four metal spokes that are sticking out, and those are the pillars that support the teeth. The teeth are manufactured by a lab before surgery, and it's a temporary set of teeth. The bite is not always completely perfect, but it's as good as we can possibly make it. The patient has these teeth that are loaded onto the prosthesis at the time of surgery. They wake up with the teeth. And then, later down the road, and I'll let Dr. Kase speak to this a little bit more. Those teeth will be replaced for a more permanent, more aesthetically pleasing, more functional set of teeth.

Dr Mike Kase: Yes. So when we get to that point, we have the prototype teeth that we deliver in the OR, which is so easy to do. It's, again, so much better than the zygomatic implants or the standard all on four type procedure. You might hear about where we have to do these drawn out procedures where we essentially attach the teeth by resins and light curing materials during the surgery, which eats up a lot of time. Well, with these, since everything's made ahead of time, they literally just screw in. It takes five minutes to deliver this in the OR, which is outstanding for everybody. But again, like Dr. Ponto said, that's just a temporary, that's meant to have the patient with Teeth when they wake up, you know, good psychosocial response. And then, allow them to kind of develop their bite again and allow those tissues to heal.

So once they're stable after a couple months, then we just use the same vectors we have for those implants. We might scan the tissue again real quick so we get the correct tissue representation in the prosthesis, and then we have them mill out that final prosthesis, which is usually in a zirconia type material. So, it's much more time stable, much more aesthetically pleasing, because it goes from being a milled resin to a milled zirconia. And then, the patient has a nice long-term time, stable and functional prosthesis.

Melanie Cole, MS: Wow. Really such advanced technology. And Dr. Kase, where do the subperiosteal implants fit into the picture for cancer patients? Where in their line of therapies does this happen?

Dr Mike Kase: Just to reiterate what Dr. Ponto said is this is a new take on old technology. So, it's relatively new. I mean, there's eight years of literature on it, so it's not, brand, brand new, these new iterations. But their uses are being figured out as we go, for lack of better explanation. So, the integration into. An ongoing plan whereas the patient comes in to see us and, immediately, they have the surgery as soon as possible to get rid of the cancer and having this be a functional part in that regard really isn't possible just due to the planning that we have to do and how long it takes to actually make the subperiosteal implant.

So probably, the best answer to that would be once that patient is stable and cancer-free. And we can take our time and plan something because, like Dr. Ponto said, these patients often have these large surgical resections, and it's not as simple as just a normal patient that is getting a denture-type prosthesis. There's a lot more planning that goes into things. So once they're through with their primary therapy, that's when we're going to start looking at them.

Melanie Cole, MS: Because it really is so exciting, can you discuss any recent technological advancements in imaging and surgery that have improved the placement of subperiosteal implants, and why this is such a great benefit for patients?

Dr. Jay Ponto: This innovation is something that is now allowing people who did not have the option of having fixed teeth in their mouth, meaning anything more than a removable denture that doesn't snap into anything. This has allowed us to consider giving teeth to like people who-- actually, a lot of this was begun in Germany, about eight years ago. So, I'll say about five years ago in the United States, this was not an option for anyone.

What my message to other providers would be if patients have any sort of dental rehabilitation where they are desiring teeth, there is a chronic hole in their mouth going to the nose or the sinus. And if these patients have been told, "Oh, there is no other option for you now to either close this hole or get teeth in these areas," well, now there might be, it's very exciting. I have other patients where they have traumatic injuries, benign tumors, malignant tumors, a history of benign tumors or malignant tumors, who five years ago, we would just say, "Oh, well, here's your removable prosthesis." And they would complain that it falls out all the time and they can't go out in public as easily. Maybe their grandchildren tease them, which I got last week from someone, they can't chew, they speak funny. Now, there might be an option for you. Now, we might be able to come up with a solution that could dramatically increase your quality of life.

Melanie Cole, MS: Dr. Kase, last word to you, as you think about these implants and the patients that they help, what would you like other providers to know about the work that you're doing at UAB Medicine?

Dr Mike Kase: I would just like to really offer the point that, as complex as it appears, as innovative as it is, that it's really not overly difficult, and I don't want people in the community even to think that, well, this is way beyond my ability to even comprehend doing this. Like as long as you have an excellent surgeon like Dr. Ponto or one of our other surgeons in our department here that can work with you, you can do this on your own too. Like, I was lecturing to residents a week or so ago about this. They all were looking at me, like how, crazy and amazing it is. But it's really straightforward. You just get a good tooth set up for the patient to where you want the teeth to be, and then essentially provide that information to the surgeon and the company we work with, and then have the ability to screw teeth in place. It's not as complex as it looks.

And going back to what Dr. Ponto just said, is it opens up the possibilities for patients that otherwise might not have had any sort of option to have something functional like this. So, it's something that everybody should consider, I think. And we're just thankful that we have good surgeons here that can do this, and we do this a lot. We were just planning one this morning actually. So, I just think that it should be part of treatment planning for a lot of different patients. And I would just like to make sure people know that, it's something within the realm of capability for most practitioners out there. It's technology these days make things that are super complex be much more easy to do. So, I would just like to leave on that note.

Melanie Cole, MS: Thank you both so much for joining us today. You really are both such great guests every time you join us. So, thank you again. And for more information, you can always visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. I'm Melanie Cole. Thanks so much for joining us today.