Cone beam computed tomography in endodonticsCommander John S. Evered, DC, USN and Commander Terry Webb, DC, USNPurposeComputed tomography (CT) was invented by Sir GodfreyNewbold Hounsfield and Allan McLeod Cormackworking independently in the late 1960' s and early1970's. They shared the Nobel Prize for Medicine in1979 for this discovery. It was developed as a way to seea "slice" of a patient's body which was not available beforewith two-dimensional radiographs. CT machines arerelatively large and expensive and expose the patient tohigh doses of radiation. Cone beam CT (CBCT) wasdeveloped in the late 1990' s as an outgrowth of computedtomography. It offers reduced radiation exposure andscan time. Cone beam CT was approved by the FDA in2000, and then introduced to North American dentists in2001. Since then, it has presented new opportunities inendodontic diagnosis and treatment planning. This clinicalupdate will define cone beam CT, present its diagnosticabilities compared to conventional two dimensionalradiographs, and explain its endodontic applications.