Table 2.

Statistical analysis of δ^a

		Clivus			Occipital protuberance			Mental protuberance			C5
		LR	CC	AP	LR	CC	AP	LR	CC	AP	LR	CC	AP
All patients	Number of δ values	867	858	858	824	824	824	813	813	813	831	831	831
	Median (mm)	−1	1	0	−1	0	1	0	1	0	0	1	2
	(Range)	(−4 to 3)	(−4 to 6)	(−3 to 4)	(−6 to 3)	(−7 to 6)	(−4 to 5)	(−4 to 5)	(−7 to 8)	(−8 to 10)	(−8 to 6)	(−6 to 6)	(−7 to 9)
	1σ (mm)	1.2	1.4	1.2	1.4	1.7	1.3	1.5	2.3	1.9	1.9	1.7	2.3
Underweight	Number of δ values	123	123	123	123	123	123	112	112	112	112	112	112
	Median (mm)	−1	1	1	−1	1	1	1	1	0	0	1	2
	(Range)	(−3 to 2)	(−3 to 6)	(−1 to 4)	(−5 to 3)	(−4 to 6)	(−2 to 4)	(−3 to 4)	(−2 to 4)	(−2 to 4)	(−5 to 5)	(−2 to 5)	(−2 to 7)
	1σ (mm)	1.3	1.5	0.9	1.4	1.6	1.1	1.6	1.5	1.2	1.7	1.5	1.8
Normal-weight	Number of δ values	512	512	512	501	501	501	501	501	501	501	501	501
	Median (mm)	−1	1	0	−1	0	1	0	2	0	0	1	1
	(Range)	(−4 to 2)	(−4 to 5)	(−3 to 4)	(−6 to 3)	(−5 to 5)	(−4 to 5)	(−4 to 5)	(−6 to 7)	(−8 to 6)	(−7 to 4)	(−4 to 6)	(−4 to 8)
	1σ (mm)	1.1	1.4	1.2	1.3	1.7	1.3	1.5	2.2	1.7	1.6	1.7	2.2
Overweight	Number of δ values	158	158	158	147	147	147	158	158	158	158	158	158
	Median (mm)	0	0	1	−1	−1	1	1	1	0	−1	0	2
	(Range)	(−4 to 2)	(−4 to 5)	(−3 to 4)	(−4 to 2)	(−7 to 4)	(−3 to 4)	(−4 to 4)	(−7 to 8)	(−4 to 10)	(−8 to 6)	(−6 to 3)	(−4 to 9)
	1σ (mm)	1.2	1.5	1.2	1.4	1.9	1.2	1.5	2.8	2.6	2.3	1.8	2.1

Translational directions are expressed in left–right (LR), craniocaudal (CC), and anteroposterior (AP) directions. ^aDiscrepancy of the position between treatment and treatment planning.