Table V.

Wire landmarks: comparison of differences between two-dimensional and three-dimensional measurements of 20-mm horizontal wires and 40-mm vertical wires for 28 skulls imaged in 3 positions

Wire orientation	Skull side	Measurement	Difference*		Absolute value of difference†
			2D	3D	2D	3D
Horizontal	Left	Mean error (mm)	−0.28	0.18	0.5	0.34
		% error	1.4%	0.9%	2.5%	1.7%
		SD	(0.58)	(0.38)	(0.39)	(0.23)
	Right	Mean error (mm)	−0.20	0.03	0.47	0.19
		% error	1.0%	0.2%	2.4%	1.0%
		SD	(0.56)	(0.24)	(0.34)	(0.14)
Vertical	Left	Mean error (mm)	−0.47	−0.23	0.56	0.25
		% error	1.2%	0.6%	1.4%	0.6%
		SD	(0.50)	(0.23)	(0.39)	(0.19)
	Right	Mean error (mm)	−0.50	−0.36	0.61	0.37
		% error	1.3%	0.9%	1.5%	0.9%
		SD	(0.60)	(0.26)	(0.47)	(0.23)

2D, two-dimensional; 3D, three-dimensional.

^*Average of 84 measurements (measurement in image–known length).

^†Average of 84 measurements |measurement in image–known length|.