I was very young when I first heard of the ancient tale from India of the blind men and the elephant. This tale spread far and wide, but the Indian version is probably the original and is definitely the most succinct.
From the Wikipedia entry,
Ramakrishna Paramahamsa used this parable to discourage dogmatism: "A number of blind men came to an elephant. Somebody told them that it was an elephant. The blind men asked, ‘What is the elephant like?’ and they began to touch its body. One of them said: 'It is like a pillar.' This blind man had only touched its leg. Another man said, ‘The elephant is like a husking basket.’ This person had only touched its ears. Similarly, he who touched its trunk or its belly talked of it differently. In the same way, he who has seen the Lord in a particular way limits the Lord to that alone and thinks that He is nothing else."
I shall refrain from any discussion of how this applies to modern American politics and the religious sphere. But to dentistry, it also has tremendous relevance.
For my entire career I've been intrigued by how 2-dimensional X-ray images represent, and misrepresent, 3-dimensional objects. I've posted before on how the level of bone or a small chip in enamel can be superimposed over the rest of the tooth in such a way that it looks like a cavity. Well, we took some X-rays recently that show a large cavity with tremendous variation in how it actually looks.
As we look at the images, recognize that the dark curvy lines inside the teeth are the outlines of the root canal. The white lines are an existing root canal treatment and post. The other white things are metal restorations.
In this first image, focusing on the tooth with the question mark, we see a hint of darker gray under the light filling, which could be a cavity:
However a dentist could perhaps be excused for thinking nothing of this shady shading and, if no open decay was visible to the eye (or touchable to those little sharp silver things that we're always poking around with), leaving this tooth be. Because, you see, the line of the dense bone throws a shadow right along this part of the tooth and it's supposed to look a little darker there. Same picture, with a line drawn along the bone crest:
Yet a Full Mouth Series of radiographs picks up different views of the same tooth. Much like those chaps investigating the elephant, we start to see different aspects of the same thing:
And for the win:
So multiple radiographic views of teeth are often vitally important in diagnosis. This is even more true when we get into diagnosing periodontal disease, endodontic lesions (infections in root canals), cysts and the like. The new 3-D scanners are a great advancement in this regard. They do not yet have the resolution to detect small cavities, but in short order they probably will. Until then, it's sometimes a challenge to know the tusk from the trunk.