Table 2.

Error analysis for upper-arch length projected onto the midsagittal plane in millimeters measured from models and cephalometric radiographs

Statistics	Radiographs	Models
Mean of difference between readings	0.24	0.15
Confidence interval: lower limit	0.04	-0.02
Confidence interval: upper limit	0.45	0.32
Coefficient of repeatability	1.13	0.92
Number of points in the warning zone	9	6
Number of out-of-control points	2	2