ANB Angle
Pronunciation: A-N-B angle
Also written as: ANB — A Point–Nasion–B Point Angle
A cephalometric angle representing the anteroposterior skeletal discrepancy between the maxilla and mandible, derived by subtracting SNB from SNA. It is the primary numerical indicator of skeletal class.
Full Definition
The ANB angle is calculated on a lateral cephalogram and quantifies the sagittal jaw relationship. A value of approximately 2°–4° is considered Class I; a larger positive value indicates a Class II (maxillary protrusion or mandibular retrusion) pattern, while a negative or very small value indicates a Class III pattern. In editorial practice, ANB must be written as a three-letter uppercase acronym and reported with a degree symbol. Editors must take care that the value is mathematically consistent with the SNA and SNB figures stated elsewhere in the same document.
Usage
Usage note: Negative ANB values should be presented with a minus sign (−2°), not in parentheses. Confirm mathematical consistency with SNA and SNB wherever all three appear.
In Context
- "An ANB angle of −2° was consistent with the patient's Class III skeletal pattern." — Orthodontic referral letter
- "The editor flagged that the reported ANB angle did not equal SNA minus SNB, indicating a transcription error." — Proofreading note