This fact is from Cephalometric Analysis in Orthodontics. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
SNB = 80 degrees mandible position relative to cranial base
ANB = 2 degrees skeletal relationship Class I
ANB greater than 4 = Class II skeletal
ANB less than 0 = Class III skeletal
Wits appraisal when ANB unreliable
Tweed triangle = FMA FMIA IMPA
Steiner analysis = SNA SNB ANB.