Now you see it, now you don’t

Sometimes in endodontics, we miss signs, symptoms or findings that are important to diagnosis or prognosis. Sometimes our brain fools us into thinking we see or find things that aren’t really present. This case is a good example of both of these possible errors. The patient presented complaining of mild tenderness to bite on the 26. The tooth was slightly tender to percussion, mobility was normal and there was slight tenderness to palpation on the palatal aspect. Periodontal probing was within normal limits. Here are the intra-oral radiographs:

Bitewing cracked tooth

PA - Cracked toothCracked tooth PA

I decided to take a CBVT scan. The main finding on the scan was a lucency at the mesiopalatal aspect of the marginal tissues.

CBVT_Crack1

CBVT_Crack3

CBVT_Crack2

My plan was now to raise a flap to investigate. Once LA had been applied I probed again. This time I found a narrow deep pocket at the mesiopalatal aspect of the tooth. The locating of a pocket after giving LA that had not been found prior to LA is something that happens in my practice on an occasional, but recurring basis. In fact, it’s been happening since one of my demonstrators made me look silly during my endo specialty program by finding a pocket that I said was never there. I think there are a couple of factors behind this:

1. We are happy to probe more firmly when the patient is numb;

2. Radiographic findings, especially on CBVT point you to a specific location to probe for a pocket.

In a case such as this, the symptoms, followed by the radiographic finding increases the probability of a fracture being present. The added finding of a deep, narrow pocket increases the probability even more. That said, the fracture is not confirmed until visualised. So, a flap was raised and the root surface stained with methylene blue. The visualised crack confirmed the diagnosis.

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The CBVT helped immensely in this case. However, it’s easy to look at the CBVT and think, “Ah, I see the crack!” (go back to the bottom CBVT image above and look again),  but also have a look around the rest of the teeth shown in the CBVT. Almost all of them seem to have lucent lines running through them that look like”cracks”. It is very dangerous to look at the lucent line on a CBVT and “diagnose” a crack. All we have in this case from the CBVT is a finding that may be typical of a pattern of bone loss associated with a crack. It added to the other findings to lead to the final confirmation of the diagnosis of cracked tooth via visual inspection.

Let me know your thoughts on this in the comments section below.

Pat Caldwell

3 Responses to “Now you see it, now you don’t”

  1. Dylbert February 1, 2014 at 11:00 pm #

    Excellent diagnostic skills Pat. I love the case presentations you share here. The walk through from history, exam, special tests and diagnosis with clinical and radiographic images in a succinct,
    interesting and humorous style is a joy.
    Would you ever consider resecting the palatal root of an upper molar, or is this one toast?

  2. Pat Caldwell February 2, 2014 at 9:39 am #

    Hi Dave, I’m glad you’re enjoying the site. We’re planning to extract this tooth and place an implant. Resection of the mesiobuccal or distobuccal roots would be considered, but I don’t think there are too many circumstances where we would resect the palatal root and leave the buccal roots supporting the crown. It certainly has been done, and management of occlusion to limit the forces on the tooth would be paramount.

  3. Mateus Miranda February 6, 2014 at 5:33 am #

    Amazing Pat! I would have missed that one for sure. Thanks for sharing it with us and for making us think out of the box. Cheers Mate!

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