Measurement · MAX
Maxillary length (ANS–PNS)
Loading the reference ceph.
Definition
The length of the bony palate: from the anterior nasal spine to the posterior nasal spine.
How
Measure the straight-line distance ANS→PNS in mm. This is the palatal plane's own length.
Purpose
Direct size read of the maxillary base. A short palate means a genuinely small maxilla (not just a retropositioned one) — relevant for expansion/protraction planning, and for airway thinking since the palate is the nasal floor.
High
Above the norm reads as a long maxillary base.
Low
Below the norm reads as a short maxillary base — a truly small upper jaw (distinct from a normal-size maxilla positioned back).
This is a reviewed tracing on one real cephalogram — the same ceph on every page in Learn — so Maxillary length (ANS–PNS) here is a real reading and not a diagram.