Development of imaging selection criteria and procedures should precede cephalometric assessment with cone-beam computed tomography

Cone-beam computed tomography (CBCT) systems for craniofacial imaging are now available from several manufacturers. CBCT potentially provides opportunities for 3-dimensional cephalometrics in orthodontic assessment of bony landmarks and air-bounded surfaces such as the facial skin. Two-dimensional cephalogram simulation could facilitate the transfer of growth projections from existing data sets as a starting point for use of a new 3-dimensional paradigm. Three methods are described to simulate conventional 2-dimensioinal cephalograms from CBCT images and volumetric data sets. However, certain precautions are required to assure that selection criteria and imaging parameters guarantee a radiation dose that is as low as reasonably achievable.