cephalograms

Cephalograms are radiographic images of the craniofacial region produced with a cephalostat that stabilizes the patient's head during X-ray exposure. The resulting image is typically two-dimensional, most often a lateral view of the skull and face, though posteroanterior (PA) projections are also obtained.

In lateral cephalometry, a fixed geometry of X-ray beam and a standardized head position yield a profile view that enables assessment of the relationships among the cranial base, maxilla, mandible, and soft tissues. PA cephalograms provide frontal symmetry information and aid in detecting asymmetry. Modern practice frequently uses digital cephalometry, with landmarks and measurements identified on computer software; traditional methods may rely on acetate tracings.

Cephalograms are used chiefly in orthodontics and orthognathic surgery planning. They support diagnosis of malocclusions, growth assessment, treatment planning, and evaluation of treatment effects. They also permit assessment of airway space, hyoid position, soft-tissue profile, and craniofacial harmony. Landmark-based cephalometric analyses (for example, analyses that use landmarks such as Sella, Nasion, A point, B point) quantify skeletal relationships and dental positions to guide decision-making.

Limitations include the inherently two-dimensional view of a three-dimensional skull, potential magnification error, and landmark identification variability. Radiation exposure is low but not negligible, so exposure should be justified and protective measures used. Digital techniques reduce tracing time and enable superimposition across time points; three-dimensional imaging (cone-beam CT) may be used as a supplement but does not replace cephalograms in routine planning.

Cephalography originated in the early 20th century and became standardized with methods such as Broadbent's analysis in the 1930s, forming the basis for modern cephalometric assessment in dentistry and craniofacial medicine.