What does an ANB angle greater than 4 typically indicate?

An ANB angle greater than 4 degrees typically indicates a Class II skeletal pattern. The ANB angle is a measurement used in cephalometric analysis to assess the positional relationship between the maxilla (upper jaw) and the mandible (lower jaw). Specifically, it is the angle formed between the points A (the deepest point of the maxillary arch), N (nasion), and B (the deepest point of the mandibular arch).

In orthodontic terms, a Class II skeletal relationship often suggests that the maxilla is positioned relatively forward to the mandible, which results in the mandible being retruded or positioned further back than normal. When the ANB angle exceeds 4 degrees, it shows a significant discrepancy favoring the maxilla, indicative of a Class II relationship.

This dental and skeletal classification helps in diagnosing malocclusions and determining appropriate treatment modalities in orthodontics. Other angles associated with normal and Class I relationships tend to have lower ANB values, closer to 2 degrees or lower for normal (neutral position), making them less applicable to an ANB angle greater than 4. Similarly, a Class III skeletal pattern is characterized by an ANB angle that is typically 0 degrees or less, indicating a protruded