Treatment Planning on a CBCT: example patient #1


Let's take a look at our first CBCT example. This patient has walked into the office. Let's assume, of course, that their dentist is addressing some of their more urgent restorative needs. But there's a couple things in the sinus here that I want to highlight and look at. They've been referred for an implant, two implants actually, on the upper right side. They're going to be replacing tooth number two and number three in that area. So what are we going to do?

First, we're going to take a look at the CT scan here and kind of scroll through. We've got our panel here, which gives us an overview. We can see when we look at that right sinus, nothing really jumps out. The sinus is pretty clear. We have a radiolucent look. It's not grossly radiopaque. There might be a little bit of radiopacity here, but at this point, nothing that really strikes me as significantly concerning. I think a little bit of this is kind of some bilateral artifact.

So let's just take a scroll through. This is our coronal image, and let's try to see what we get here. As we start out in the posterior portion of the sinus here, scroll through. This section here, you can see, that's what you want to see. Black, radiolucent, healthy. I don't see any inflammation. I don't see any irritation. I don't see any inflamed membrane or lining. So we're looking good.

Keep scrolling forward, and we continue to see that healthy black radiolucent sinus. Things are looking good so far. We're going to start to see here, probably about here, we're getting into the area of where we would be looking at placing our number 2 implant. And it keeps scrolling forward.

Now we're starting to see something here. As we get to the spot where we would be placing implant number 3, we start to see a radiopacity. Somewhat small, ovoid, well-defined. This does not look like sinusitis to me. This looks like some type of cyst. There are cysts that are common in the sinus, like mucous retention cysts and other things that aren't worrisome. Nonetheless, at this point, we don't necessarily know what this is.

And it is very close to the area of our proposed sinus lift or sinus graft for our molar implant placement. This is a patient that I do not think that there is a contraindication to the sinus lift procedure. However, this is somebody that I would consult with an ENT physician to have them comment on what they think this is and if it requires any treatment. I would also relay to them what we're doing. This might be a case where I picked up the phone and talked to them personally, letting them know we're going to be doing some grafting in there, we're elevating the membrane. What is that pathology? What are the things going on? And probably one of two things is going to happen. Either the ENT surgeon might say that this is not something to worry about, you can continue with your procedure. Or they may say, you know, we're going to do some treatment on there and resolve that before you do surgery. The third scenario would be it is something pathologic that is worrisome and needs to be treated. In this particular patient's case, I don't think that would be the case. But that's why we take those steps to ensure that we know what the diagnosis is before proceeding.

So with this patient, I would hit pause. I would consult with an ENT surgeon and we would go from there. Let's assume that that patient has seen the ENT surgeon. They've come back to us. This is resolved and is no longer there. It's not a concern. Now we've got to plan two implants for molars number two and three here.

I start on the pano. I'm going to get a measurement here and I want to see what type of bone height we have. We are planning number three somewhere here. We've got about close to 12 millimeters of bone. So we have enough bone in that area. The implant system that I'm typically familiar with would provide me an 11.5 millimeter implant. We should be good on height, on bone height, for an implant placement in that region. Let's slide back here and look where we would have our number two implant. We're going to look and see that we've got about 7.5 millimeters. Maybe I'm a little generous there, maybe 7 millimeters of bone.

When we look at that bone height, the smallest implant that I'm comfortable using in the posterior is going to be an 8 millimeter implant. For me, I don't really have enough bone to just place the implant as is. I need to come up with maybe realistically another millimeter of bone or a millimeter and a half to ensure that the apex of my implant is fully covered in bone.

This would be a good time to utilize an indirect sinus lift for placement of that number two posterior molar implant. Our rationale is going to be that we have more than six millimeters of bone availability. As Miesch and other authors have commented, typically you can predictably get one to two millimeters of bone height from an indirect sinus lift. Some authors have said as much as three to four. I'll tell you even in my hands, predictably getting three to four millimeters every time is difficult. I think two millimeters is a more realistic goal. And so in this scenario, that six millimeters of bone allows us to get to that eight to nine millimeters bone height mark to provide space for an eight-millimeter implant.

Here we've got seven and a half millimeters. I know if I can get two millimeters, I can get nine and a half millimeters of bone. I can safely place an eight-millimeter implant. So I'm going to plan an indirect sinus lift here in the posterior with a goal of getting an additional two millimeters of bone height and an eight-millimeter implant. Here I don't need one for the number three implant. We'll place that just routine placement. Both of those can be placed at the same time.

The last thing that we're going to do is confirm that we have enough bone width. Now, when I scrolled through, I saw that we clearly did. However, for implant planning purposes, we do want to confirm a measurement indicating that we have enough bone width in these areas to place an implant of an acceptable size. And we can clearly see here, you know, we've got seven and a half, eight millimeters of bone at both of those sites, actually. So we'll have plenty of bone to place a four or five-millimeter implant, no problem.

Alright, that concludes the first CT scan. Let's go ahead and take a look at the second CT scan.

Lesson Summary

The analysis of the second CT scan reveals the following:

  • The first CT scan indicated that the patient needs two implants on the upper right side.
  • Upon review of the second scan, there are no concerning findings in the right sinus.
  • A small, well-defined radiopacity is observed near the area where the implant for tooth number three would be placed. This is suspected to be a cyst.
  • Consultation with an ENT physician is recommended to determine if any treatment is required before proceeding with the implant.
  • The second CT scan confirms sufficient bone height for implant placement.
  • However, additional bone width may be needed for the implant for tooth number two.
  • An indirect sinus lift is planned to obtain the necessary bone height.
  • This will allow for safe placement of an eight-millimeter implant.

Complete and Continue