Dental cone beam computed tomography (CT) is a special type of x-ray machine used in situations where regular dental or facial x-rays are not sufficient. It is not used routinely because the radiation exposure from this scanner is significantly more than regular dental x-rays. See the Safety page for more information about x-rays. This type of CT scanner uses a special type of technology to generate three dimensional (3-D) images of dental structures, soft tissues, nerve paths and bone in the craniofacial region in a single scan. Images obtained with cone beam CT allow for more precise treatment planning.
Cone beam CT is not the same as conventional CT. However, dental cone beam CT can be used to produce images that are similar to those produced by conventional CT imaging. With cone beam CT, an x-ray beam in the shape of a cone is moved around the patient to produce a large number of images, also called views. CT scans and cone beam CT both produce high-quality images.
Dental cone beam CT was developed as a means of producing similar types of images but with a much smaller and less expensive machine that could be placed in an outpatient office. Cone beam CT provides detailed images of the bone and is performed to evaluate diseases of the jaw, dentition, bony structures of the face, nasal cavity and sinuses. It does not provide the full diagnostic information available with conventional CT, particularly in evaluation of soft tissue structures such as muscles, lymph nodes, glands and nerves. However, cone beam CT has the advantage of lower radiation exposure compared to conventional CT.