Jeffrey Caso There has been great confusion and many questions regarding what the numbers really mean when we activate the cursor details. Sure, at first, it’s a bit annoying having the cursor details box attached to our cursor. It follows us around and can be in the way of what we are trying to see. I for one have gotten used to it and like that fact that, when activated, it is where I am looking. No need to move your gaze to the bottom of the screen away from the restoration. It kind of grows on you.
The other issue is, just what do those numbers mean? Well, the height of fissure is just that. It’s a measurement of the thinnest part of our central fissure. That makes sense. It’s the other reading or the thickness number that can throw us off. How can we have a low point in the Height of Fissure measurement as one number, and when we move the cursor through the fissure area we get thickness readings that are sometimes less? Even more confusing is that sometimes we cannot replicate or find the Height of Fissure reading. Where is the low spot?
The answer to this phenomenon is simple. The Height of Fissure is measured in the view that is set by you in the insertion axis step. The Thickness is measured in the view you currently have on the screen. So, for example, in this series of screen shots I have created an artificial low spot.
You can see the Height of Fissure and the Thickness are the same in this location. Keep in mind that the orientation of the model on the screen is exactly the insertion axis. I know that because I have selected from the side bar, the View Options tab and clicked on occlusal. This view is the insertion axis view and the reference for the Height of Fissure number.
Now look what happens when we rotate the model little bit.
The thickness, in exactly the same location as before, is now less than the Height of Fissure. Let’s look at one more example.
Here in the same spot again, the thickness is so much greater. Why? Because the reference has been changed, not for the Height of Fissure because that is fixed, but for the Thickness measurement.
That is the reason for these seemingly conflicting numbers. To reliably evaluate your restoration, always look at it from the insertion axis view. That will set the point of reference exactly the same for both of those readings, and you will be much more accurate in this important part of the design process.
