Reading Veterinary Dental Radiographs and X-rays

One of the biggest things that we run into in general practice is trying to interpret dental radiographs from a periodontal standpoint and when you get down to it, it’s pretty easy. There’s really only two changes that we see that are significant with perio and I’m going to tell you both of these in about a minute. Looking at this is a pretty normal radiograph of those three teeth in the bone surrounding them.

What we’re looking for, the number one thing that we’re looking for, is a change in where those arrows are pointing. That level of bone is called the marginal bone height and if we get any alterations to that, if we get any decrease in that height adjacent to the tooth where that bone starts to move down toward the apex, that’s significant and that is an indication that we have periodontal disease.

That’s one thing, to give you an example we ‘ve got a cat mandible here, and if you look at those maroon arrows, that’s where the bone level should be on that right mandibular molar and the blue arrows are where the bone level actually is. Not only on that tooth but, on the other two teeth we’ve got a decrease in the marginal bone height because those maroon arrows point to the neck root interface and that’s about where that bone should be and you can see that we got some early furcation bone loss and some horizontal bone loss where that alveolar bone height has dropped on all of those teeth. That’s one thing that we’re looking at.

The other thing that we’re looking at is an increase in the width of the periodontal ligament space. Those arrows are pointing to that radiolucent or that dark area around that tooth root between the root and the bone. That’s termed the periodontal ligament space, as most of you know and it starts usually at that top arrow where we start to see an increase in the width of that space when we first start to get bone involvement which extends from our gingival inflammation and our perio from a soft tissue standpoint.

Again,an example of that. Another image of that same area, that blue arrow is pointing to exactly that adjacent to that mandibular first molar where we’ve got an increase in the width of the periodontal ligament space there. You can also see that’s really significant in the furcation. If you look to the far right, we’ve got bone loss there as well and also on that second molar on the left side of the screen. All those areas are affected with perio. Those are basically the things that we need to look at. Now, that being said, when we have that kind of bone loss we have to ask ourselves questions about whether we can actually alter that and if we can alter it, fantastic. We can maybe do some curettage to remove the granulation tissue that’s going to be in those dark areas and then plus or minus a bone graft, utilizing periodontal flaps which is a whole nother part of a course. Just to give you a general idea, we could and we did do some tissue regeneration with curettage and bone grafts on tooth to save that tooth and we were successful doing so. You have to ask yourself a question, can we alter the progression based on the amount of bone loss that is present on the individual patient and if we can’t, then that is probably going to be an extraction.

Let’s look at an example of that. Take a look at that briefly. There are mainly two areas that are pretty blatant there that show changes in the gum tissue adjacent to the teeth. Take a note of that, see if you can see what those two changes are. I’ll give you just a second here to conceptualize that and think about that. Two changes there in the gum tissue adjacent to the teeth and moving forward, here are those changes.

We’ve got an increase in the hyperemia of the gum tissue right in that furcation on that second premolar which is the first arrow on the right. Then we see some inflammation that’s not as pronounced and we’ve got recession adjacent to the distal root on that third premolar. Those are the two main things there, not horrendous. Those look acceptable just from a visual standpoint but, when we look at those radiographically, what do you see?

Take a look at that, take metal note of that. Answer to yourself, see what you see (or put it in chat). On the next slide we show the level of bone loss.

So we’ve got horizontal bone loss, a decrease in the marginal bone height that’s significant there so it’s dropped down from the neck root interface moving toward the root tip or the apex on that distal root where we have the recession. We’ve got an increase of the periodontal ligament space that’s significant all the way to root apex. So can we alter the progression of that? The answer’s no, that’s pretty significant.

So those are extractions, even though they didn’t look that bad, grossly. Those are extractions, for sure.

So that’s an example of one case, let’s look at another one. Tell me what you see there.

That one’s a little more obvious. Specifically we’ve got that area there that’s bleeding on probing and pretty inflamed. We also, if you look a little further where the shadow is between the molar and the fourth premolar, there’s some inflammation there. There’s some inflammation in the furcation that are less obvious but, looking at that radiographically we see again those changes where we have an increase of periodontal ligament space around the distal root of that molar that are significant. Not only on the distal side but, also on the mesial side of that distal root.

We’ve got compromise of the second molar there. You can see the bone heights dropped, the space is widened, so all those things are present. Can we alter that? Maybe, the prognosis is not very good because it looks like on that distal root we might have a dead tooth where the space around that root in the bone is increased. There’s a possible increase even if the mesial root there around the root tip so we would definitely not recommend doing anything to that. There’s too much indication that that tooth is dead because that change has, especially around that root tip, has progressed from the periodontal changes to involve the apex where the blood supply goes in. So, the chance of that tooth being dead as well as having periodontal disease is pretty good. If we were going to save that, we would have to do some pretty valiant efforts from the cleaning and bone graft standpoint. We would also have to do a root canal so that would not be something that we would recommend and as you see, both of those teeth were extracted.

Those are some of the common examples that we can take into and start to think about when we’re seeing our patients in our practice when we’re looking at our radiographs.