Are these two dental x-rays from the same person?

[Sandy Larsen]

I'm studying a situation where a dental x-ray may have been accidentally assigned to the wrong person.

My understanding when I first took the case was that the person was apparently missing molar #30. Here are photos of the exhumed teeth:

 

 

I was surprised to find such a narrow gap between #29 and #31. Molars #31 and #32 had managed to make a substantial translational movement -- with virtually no tipping -- as though the person had received orthodontic treatment. (Teeth #31 and #32 may appear to be tipping, but their angles are merely due to the slope of the mandible and gum line in that area.) Yet it is known that this person had not received orthodontic treatment.

Going through the material I was handed, I came across an x-ray of the teeth taken in 1958. It is of the same side of the teeth as missing molar #30.

1958

(Please disregard the all lines and labels drawn in by prior researchers.)

I was even more surprised to see this x-ray, which you will understand in a moment. It shows precisely what I was expecting to see in a case where molar #30 is missing. In this case we do see a wide gap between #29 and #31. And we see molar #31 tipping down into the space left behind by molar #30, and molar #32 tipping in the same direction behind that.

The reason I was surprised by the x-ray is that it was taken only five years before the death of this individual. Which means that those two tipping molars had to have spontaneously uprighted themselves, and then made an approximately 1/4 inch translational movement within that five year period of time. Without orthodontic treatment. I began to suspect that this x-ray did not belong to this person who'd been exhumed, and I decided to study the teeth more carefully.

Among the materials I was given were x-rays of the exhumed teeth. For the side with missing molar #30, I had two overlapping x-rays. I combined the two into a single x-ray, which was easy to do due to substantial overlap making alignment a simple task.

analysis.

Exhumation X-Ray

Comparing the composite x-ray above to the photo of the exhumed teeth below, we see that they match quite well. Unfortunately the x-rays I was given don't show the complete root on several of the teeth.

Exhumation Photo