An ANB angle of less than 0 degrees indicates which tendency?

An ANB angle, which is the angle formed between the A-point, the Nasion (N), and the B-point, is a significant metric in cephalometrics for assessing skeletal relationships in orthodontics. An ANB angle of less than 0 degrees typically indicates a Class III skeletal relationship.

In the context of orthodontic classification, a Class III relationship is characterized by a more protruded mandible relative to the maxilla. When the ANB angle is negative or below 0 degrees, it suggests that the A-point is located further back than the B-point in relation to the Nasion, which is indicative of a skeletal Class III tendency. This classifies the individual as having a mandibular prognathism or maxillary retrognathism, highlighting the potential for a Class III malocclusion.

Other classifications do not align with an ANB angle below 0 degrees. Class I indicates a balanced skeletal position, and Class II signifies a relationship where the maxilla is more prominent than the mandible, which would result in a positive ANB angle. Class IV is not commonly recognized in standard orthodontic classification and is generally not associated with any specific skeletal relationship. Therefore, a Class III tendency is correctly identified by the