Which ANB value corresponds to Class III malocclusion?

Which ANB value corresponds to Class III malocclusion?

• A. ANB = 2°
• B. ANB ≤ 0°
• C. ANB ≥ 4°
• D. ANB = -2°

Answer: (B)

ANB angle shows how far the maxilla sits in front of the mandible relative to the cranial base. A normal value is about 2 degrees. A larger positive ANB points to Class II malocclusion, where the maxilla is ahead of the mandible. When the mandible is ahead of the maxilla (or the maxilla is retruded), the ANB becomes zero or negative. That’s why an ANB value of zero or negative corresponds to Class III malocclusion. The key idea is that this skeletal pattern shifts the relationship to zero or a negative value, indicating the Class III pattern.

ANB angle shows how far the maxilla sits in front of the mandible relative to the cranial base. A normal value is about 2 degrees. A larger positive ANB points to Class II malocclusion, where the maxilla is ahead of the mandible. When the mandible is ahead of the maxilla (or the maxilla is retruded), the ANB becomes zero or negative. That’s why an ANB value of zero or negative corresponds to Class III malocclusion. The key idea is that this skeletal pattern shifts the relationship to zero or a negative value, indicating the Class III pattern.