| Measurement | Description | Normal Value | Class II / III |
|---|
Understanding cephalometric analysis
A cephalometric analysis translates the complex three-dimensional relationships of the skull, jaws, and teeth into a series of angular and linear measurements that can be compared to population norms. The most commonly used analysis is Steiner's analysis, which uses SNA, SNB, and ANB as its primary skeletal indicators.
SNA tells you where the maxilla sits relative to the cranial base. SNB tells you where the mandible sits. ANB - the difference between them - tells you the relative jaw position: positive values indicate maxilla forward (Class II tendency), negative values indicate mandible forward (Class III tendency). A normal ANB is 2° ±2°.
No single measurement makes a diagnosis. A patient with ANB of 5° could be Class II because of a prominent maxilla, a deficient mandible, or both. The skeletal measurements must be interpreted alongside dental measurements (overjet, overbite, interincisal angle) and soft tissue analysis to plan treatment correctly.
For orthodontic cost planning after analysis, see the Braces and Invisalign Cost Estimator. For checking orthodontic readiness in children, use the Orthodontic Readiness Checker. X-ray settings for cephalometric radiographs are in the X-Ray Exposure Reference Chart.