The mnemonic
Normal, Distal, Mesial
What each word stands for
- NormalClass I neutroclusion: molar relation normal
- DistalClass II distocclusion: lower arch is distal to the upper
- MesialClass III mesiocclusion: lower arch is mesial to the upper
Why it matters clinically
Class III is the prognathic or underbite pattern.
Where it stops being reliable
Based on the first molar only and ignores skeletal and vertical relations.
Teaching aid, still awaiting independent review. Confirm facts in a standard source.