cephalometrics

Cephalometrics is a field within dental and craniofacial sciences that focuses on measuring the head, particularly the skull and face, using radiographic images known as cephalometric radiographs. The standard modality is the lateral cephalogram, though frontal and posteroanterior views are also used in some assessments. Patients are typically positioned in natural head position to reduce distortion and improve reproducibility.

Cephalometric analysis requires the identification of fixed craniofacial landmarks, such as sella (S), nasion (N), A point (A), B point (B), porion (Po), orbitale (Or), pogonion (Pog), gnathion (Gn), and menton (Me). From these landmarks, a range of angular and linear measurements is calculated to describe skeletal relationships, dental orientations, and soft-tissue profiles. Common metrics include SNA and SNB for maxillary and mandibular positions, ANB for the sagittal jaw relationship, and vertical indicators such as the facial angle, Y-axis, and Frankfort-mandibular plane angle. Additional analyses assess dental relationships, including incisor inclinations and interarch harmony. Numerous standardized analyses exist, each with specific landmark configurations and normative data.

Applications include diagnosing malocclusions and skeletal jaw discrepancies, assessing growth and development in children, planning orthodontic or orthognathic surgical interventions, and evaluating treatment outcomes. Limitations of cephalometrics involve its two-dimensional representation of three-dimensional structures, potential magnification and distortion, reliance on precise landmark identification, and variability in head position.

Advances emphasize digital cephalometry, improved standardization, and integration with three-dimensional imaging modalities such as cone-beam computed tomography, while 2D cephalometrics remains foundational for longitudinal studies and historical records.