Cone Beam CT is arguably one of the most incredible advances the entire dental profession has seen in the last few decades. While we certainly have seen many other innovations such as digital impressions, handpiece technology or laser dentistry, each of those is related to treatment. And we can only treat what we have diagnosed, and we can only diagnose what we can actually see.
Put simply, Cone Beam CT allows you to see more. It provides three-dimensional views of teeth, the TMJ or airway that have never been available before.
The technology works in a similar fashion to other radiographic imaging, such as digital panoramic systems. There is an x-ray source on one side and a detector on the other. In the case of the cone beam, the x-rays are released in the shape of a cone. As the unit spins around the patient’s head, the computer picks up a series of cephalometric x-rays with variable densities and uses a complex algorithm to rebuild them into a 3D pattern based on similar points of density.
The result is a 3D image of the patient.
While 2D images have distortion similar to the way a shadow is distorted depending on the position of the sun, Cone Beam images are free of distortion, allowing exact sizes and distances to be measured down to the 10ths of a millimetre. Another advantage over 2D imaging is the ability to view an internal slice of a Cone Beam image to view a specific plane of the anatomy without having to deal with structures in front or behind it.
Radiation exposure from any x-ray imaging is a concern, but Dental Cone Beam systems use far less radiation than a medical CT scan. Those systems capture individual x-ray slices and then reassemble them to create the 3D image. It’s similar to building a loaf of bread by grabbing one slice at a time, whereas dental Cone Beam systems grab the entire loaf at once.