Placed on the lip
The lip outline is longer and smoother than the corner, so the point slides down it.
Point · Sn
Subnasale: where the columella meets the upper lip.
At Beginner a placement counts as found within 2.1 mm of the reviewed reading.
How to find it
Press a step to be shown it on the ceph.
Each figure is the reviewed reading of Subnasale (Sn) and a typical miss, on the same ceph, at the distance the mistake usually goes.
Placed on the lip
The lip outline is longer and smoother than the corner, so the point slides down it.
Placed at the nostril shadow
The nostril reads as a dark notch just behind the true corner and looks like the junction on a low-contrast ceph.
3 measurements are built on it. Miss it, and every one of them moves.
Your record
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