Rethinking J Shaped Radiolucency: Don’t Fear This Tricky Lesion!

This tooth story is one of hope. I have written about other teeth like this—that is, difficult cases (like the recent story of the “tooth that wouldn’t heal”) but this one was different. This tooth was stubborn. No joke. In fact, I thought that this tooth was cracked … and so there was a real hesitancy to even get started on this case. What I ended up discovering was the J-shaped radiolucency that so many of us are taught to fear. But I wasn’t going to let that stop me from saving this tooth. 

Over and over again throughout my career, I’ve seen the power of giving teeth a chance. It’s a lesson I go back to often. Those experiences have shown me that my assumptions about a diagnosis could be dead wrong.  

It wasn’t until I started looking deeper, practicing patience, and trying something different with these cases that I started learning what was possible. 

Diagnosing a Sneaky J-Shaped Radiolucency

I’ve learned over time to question my beliefs about a tooth based on what I saw on the radiograph and to instead wait to lean into those assumptions and let the process be determined alongside the patient. I’ve learned this lesson, but I still see my colleagues struggle with it. The idea here is to be fully transparent with your patients. I get it, nobody wants to be wrong, do treatment, charge the patient and STILL need to remove the tooth.😱

You all know I’m about saving teeth whenever possible, and if I took out a tooth that didn’t need to be taken out, well, that would weigh on my mind. When I say I have been surprised many times in my career, that’s the complete truth. That’s why I’m honest with my patients: as long as they understand there’s so much that I don’t know until I get inside a tooth and they are willing to put in the time, money, and energy, well…if they can do that, then I’m all about trying to save their tooth! 

This is the story of a case exactly like what I’m describing. Take a look at the preoperative radiograph. As you might also see, there are many things that aren’t great here. For one, there is too much “space” in the canal system—both in the chamber and the distal canal. I like to always see the buildup touching my gutta percha. And…could there still be cotton and cavit under this crown? Oof. 

The bitewing shows everything a bit clearer. 

There shouldn’t be any gaps between that buildup and the gutta percha. That tells me there’s—unfortunately—room for contamination. The patient was asymptomatic for the most part, but there was a probing on the buccal and there was no pain to percussion. I diagnosed the tooth as Previously Treated and Chronic Apical Abscess #30.

The CBCT confirms that terrible J-shaped radiolucency that everyone is taught to fear.  

This description of a lesion is what has made so many practitioners believe that a vertical root fracture is a super hard diagnosis. But, as I have learned over the years, the J-shaped radiolucency can simply be a draining sinus tract or, of course, a sign of a vertical root fracture.  But I’ve also learned this: a deep probing does not always mean a vertical root fracture. Instead, often the body has found the path of least resistance and is allowing the infection to drain out through the sulcus, which is likely what we’re seeing here.

I’m telling you this so you remember in the future that these two signs do not 100% guarantee that the root has a vertical root fracture—so be smart as you plan your treatment. 

What to do Once the Diagnosis is Made

After a careful discussion with the patient, we decided together that we wanted to try and save the tooth.🦷

With the full understanding that the tooth could be cracked. The patient understood that if I saw a crack internally, then the tooth would have to be removed. In these cases, I give the patient two different financial breakdowns and I would never, ever charge them for a full root canal if I didn’t actually do the whole thing.  

So I started treatment and I thought I saw a crack with my microscope in the MB root. Uh oh. But I needed to be sure. Sometimes this can just be gutta percha stuck to the side of the root. I still wasn’t convinced that this tooth needed to go.

So once again, I had an informed conversation with the patient and I let her know what I saw. Together yet again, we decided to keep moving through with treatment. I medicated the tooth with calcium hydroxide for about one month and then I obturated the tooth. 

Then it was just a matter of time.

Remember, bone takes FOREVER to heal. You will not usually see any changes in the radiograph for at least 6 to 12 months. This is why I always do a one year recall and I typically don’t try to see a patient any sooner.

The patient came back for her one year recall and was fully asymptomatic with no more probings. However, I still saw some radiolucency around that root. Hmm.

Since I like to personally follow a lesion until complete healing, I called her back for a recall in another year. At two years, she was still asymptomatic and this is what she looked like:

Normally, I would consider an apicoectomy at this point, but she was still asymptomatic. So, I decide what the heck, let’s give it a little more time. At year three, this is what she looked like with the straight angle radiograph …

But, the off angle radiograph to me was more promising …

And get this—the CBCT was even more promising!

I think this tooth has finally stabilized and since this lesion was so big, I think it may heal with a little bit of scar tissue. The PDL looks a bit thickened in the CBCT, but I would say this tooth has healed pretty perfectly.  

Let’s look at it side by side. 

Man, I am so happy that I tried to save this tooth! Look at these results!  It took some time, but we had such an amazing outcome. This just goes to show you how you really can’t carry with you the silly belief that a tooth has a vertical root fracture if there’s a J-shaped radiolucency or has a probing every single time. 

I wish they would stop teaching this belief in dental school because it is doing more harm than good. You can see so for yourself in this particular case. What a revelation!👏🏽👏🏽

How about you? What’s the worst vertical fracture case you’ve run into? How did you diagnose it and what steps did you take afterwards? Let me know in the comments!

– Sonia