Cone Beam CT & 3D Imaging

Conventional X-ray images are actually 2-dimensional representations of a 3-dimensional object. Standard dental radiographs take a “flat” image of an object without the ability to determine the “third plane”:

 

In order to obtain “depth” to a radiographic image, tomography was developed. A panorex is an example of a dental tomogram, where a thin slice of the entire upper and lower jaw is visualized on film. Objects within the slice appear sharp; however, objects outside the slice are blurred:

 

Computerized tomography takes multiple 2 dimensional slices and stacks them together sequentially to develop a 3 dimensional view of an object. The slices can be oriented in different planes for different views. A computer algorithm combines the data to form a 3 dimensional reconstructed view:

Conventional medical CT scans require a large amount of radiation to visualize small areas. In addition, they have little use in most dental applications. The scanning machine has a large �footprint�. The cost of a medical CT scanner is prohibitive for a small office, and special software programs are necessary to reconstruct the data for useful interpretation.

Cone Beam CT (CBCT) technology was developed to overcome many of the above obstacles. CBCT uses �volumetric tomography� in forming direct 3 dimensional images of an object. Instead of using multiple slices to reconstruct an image, CBCT takes multiple�3D cones� to develop primary 3 dimensional views.

 

The advantages of a Cone Beam CT are many over a medical CT, and especially a conventional panoramic x-ray when evaluating a patient for surgery:

• Small areas of the body can be scanned with high resolution
• Radiation dosage is minimized
• Images displayed are unique to oral and maxillofacial surgery
• Scanners are smaller and less expensive than medical CT scanners

Cone Beam CT is extremely valuable in many areas of oral and maxillofacial surgery:

• Placement of dental implants
  • Evaluating bone density
  • Determining nerve location
  • Determining bony anatomy
• Determining root fractures
• Evaluating impacted teeth
• Assessing degeneration of the TMJ
• Facial trauma
• Bony cysts and tumors
• Airway anatomy for sleep disorders

Raw data obtained from CT scans can be utilized to manufacture Patient Specific Anatomic Models and Surgical Guides in order to accurately plan many surgical procedures (please refer to the next section).

 

Please refer to the next section on Computer Guided Surgery to see the applications of 3d imaging on your treatment!