. 2018 Jun 8;18:103. doi: 10.1186/s12903-018-0569-4

Table 1.

Descriptive comparison of differences in the interradicular distance measurements between T1 and T0, using the Wilcoxon test^a for statistical analysis

Measurement level		n	Minimum	Maximum	Mean	SD	Wilcoxon test^a	T1–T0
Maxilla
¼	T1–T0	90	−1.75	1.27	−0.07	0.52	Z	−1.189 ^b
¼	T1–T0	90	−1.75	1.27	−0.07	0.52	A. significance (two-sided)	0.234
½	T1–T0	90	−2.40	1.33	−0.03	0.66	Z	−0.127 ^b
½	T1–T0	90	−2.40	1.33	−0.03	0.66	A. significance (two-sided)	0.899
¾	T1–T0	90	−2.45	1.67	−0.22	0.75	Z	−2.505 ^b
¾	T1–T0	90	−2.45	1.67	−0.22	0.75	A. significance (two-sided)	0.012
Apex	T1–T0	90	−3.02	1.94	−0.32	1.03	Z	−2.565 ^b
Apex	T1–T0	90	−3.02	1.94	−0.32	1.03	A. significance (two-sided)	0.01
Mandible
¼	T1–T0	90	−0.68	1.35	0.30	0.46	Z	−5.237 ^c
¼	T1–T0	90	−0.68	1.35	0.30	0.46	A. significance (two-sided)	< 0.001
½	T1–T0	90	−0.87	1.71	0.42	0.52	Z	−6.113 ^c
½	T1–T0	90	−0.87	1.71	0.42	0.52	A. significance (two-sided)	< 0.001
¾	T1–T0	90	−1.33	2.49	0.45	0.62	Z	−6.051 ^c
¾	T1–T0	90	−1.33	2.49	0.45	0.62	A. significance (two-sided)	< 0.001
Apex	T1–T0	90	−1.86	2.60	0.40	0.84	Z	−4.048 ^c
Apex	T1–T0	90	−1.86	2.60	0.40	0.84	A. significance (two-sided)	< 0.001

SD standard deviation

^aWilcoxon signed rank test

^bBased on positive ranks

^cBased on negative ranks