Reading Veterinary Dental Radiographs for Non Vital Dead Teeth in Dogs

Let’s look at some common case examples of some other things that we might see that are common radiographically that are not necessarily periodontal in origin. Take a look at that, look closely at that image and make a mental note of what you see there.

Did you identify that little lesion? You’ve got some rotation on that third premolar but the blatant thing there is that little lesion. When you have something like that that’s in the unattached gingiva like you have here, which is above that line of demarcation that you see at the butt of that arrow. You see that line there that kind of continues on, you’ve got pigment in the unattached gingiva, you’ve got the lesion in the unattached gingiva and then, in the attached gingiva toward the crown, you don’t have any pigment. That is the line of demarcation in this particular patient. Anything that is toward the root tip, away from that line, or in the unattached gingiva is a. indication, not always the case but a good indication, that the tooth or teeth adjacent to that area are possibly non vital.

Take a look at this radiograph of the exact same patient. What do you see there? Pretty obvious, huh?

You’ve got a really large pulp cavity diameter in that tooth as opposed to the pulp cavity diameter in the other teeth. You do have a large pulp cavity diameter in that first premolar there as well and if you look around that root tip, you possibly have a lucency there as well that would indicate that that tooth is non vital. Any time or almost every time that you see that increase in pulp cavity diameter that tooth is non-vital and the recommendation is either root canal or extraction. In this case we also have if you look at the root to the right, not the one where the arrow is but the one to the right of that, which is the distal root on that third premolar. You definitely see that lucency around there in addition to the changes that you see around the other root where the arrow is that are not so blatant, are the reason why we have a lesion. The tooth has died and the necrotic pulp has infected the bone, caused inflammation and destruction in that bone, and then that inflammation and infection gets past the bone and into the soft tissue and that is where that lesion came from.

Look at the other side to compare and see that that’s perfectly normal versus the side where you’ve got all those changes.

Take a look at this image, see what you see. There are some changes there that you can note. They’re not really, really obvious but, there are some changes there so take a quick look at that, make a note of what you see.

If you look closely there, you are going to see that there is some discoloration. Look at these three teeth versus the color of the other teeth, especially that second left maxillary incisor that’s to the right of the arrow there. That one’s pretty white, those are kind of cream colored. Thats a good indication there might be some problems there.

Then you look at that radiographically and low and behold, two of those have a very distinct lucency. All four of those central incisors have increase in the pulp cavity diameter compared to the pulp cavity diameter in those lateral incisors. Those are all dead. The lucency again. Same pathophysiology, the tooth dies, necrotic pulp causes inflammation and subsequent bone destruction. Those are extractions, they could have root canals done on them. We don’t recommend that in general for incisors but, that might be an option. I would never personally recommend root canals on those with that much bone loss. My thought is, I want to get that inflammation and bone change gone now, not in a couple weeks when that bone heals so I’m going to recommend extraction on those every time.

You can not read in those lucencies like we see here into maxillary incisors on a consistent basis because we see a lot of the Chevron sign or a lot of lucencies around normal incisors too. You have to be really careful in interpreting those changes and if there’s any question, you need to get the patient back, reevaluate radiographically in 6 to 10 to 12 months to see if those changes are progressing. If there’s any question in these here, looking at that I would say those are perfectly normal and would not make any recommendations other than to maybe re-radiograph in a year or so depending on how old that patient was.

Another example here, very subtle change. Look at that second premolar versus the two adjacent teeth. It’s a little bit more cream colored but, not something that we jump on just looking at that grossly.

Then look at that pulp cavity diameter on that tooth. That tooth is non vital. I wouldn’t say that there’s changes yet around the root tip but that would ensue if it’s not already starting and we just can’t see definitive evidence that its there. I would say probably what changes are there would be impossible to differentiate from bone changes that are superimposed around that tooth root. I would not be able to call that by any means. That tooth is an extraction in our practice and in yours versus root canal although, the owner should be given the option but, they are almost always going to opt for extraction. We probably would not even give an option for root canal on that tooth. It’s not a critical tooth and not one that we would think would be in the best interest of the patient to save.