Table 1

		N	IF	MP	SF	NPC length	NPC angle
		N	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)
General	-	1000	3.54 (1.11)	2.25 (0.9)	2.53 (1.01)	9.49 (2.61)	76.41 (9.08)
Gender	Female	497	3.31 (1.03)	2.14 (0.83)	2.4 (0.99)	8.78 (2.32)	75.21 (9.21)
	Male	503	3.77 (1.14)	2.37 (0.96)	2.66 (1.01)	10.19 (2.7)	77.6 (8.81)
	P value	-	0.000^a	0.000^a	0.000^a	0.000^a	0.000^a
Age groups	Group 1	119	3.16 (1.02)^A	2.25 (0.9)^AB	2.43 (1.01)	9.01 (2.18)^A	79.64 (9.22)^AB
	Group 2	208	3.31 (0.88)^AB	2.13 (0.91)^A	2.5 (1)	9.92 (2.58)^B	76.38 (9.16)^A
	Group 3	226	3.58 (1.21)^B	2.05 (0.82)A^B	2.59 (0.99)	9.63 (2.81)^AB	77.1 (8.94)^AB
	Group 4	291	3.63 (1.07)^BC	2.3 (0.92)^B	2.55 (1.05)	9.27 (2.6)^AB	76.19 (8.36)^B
	Group 5	156	3.94 (1.23)^BC	2.36 (0.94)^B	2.53 (0.93)	9.49 (2.62)^C	73.42 (9.52)^AB
	P value	-	0.000^b	0.001^b	0.504	0.017^c	0.000^b
Dental status	Group 1	818	3.53 (1.12)	2.23 (0.9)	2.54 (1.02)	9.71 (2.57)^A	77.08 (8.79)^A
	Group 2	47	3.49 (1.02)	2.31 (0.98)	2.43 (0.92)	9.12 (2.5)^B	76.3 (9.02)^B
	Group 3	48	3.40 (1.05)	2.2 (0.95)	2.4 (0.91)	8.65 (2.82)^B	74.7 (7.93)^AB
	Group 4	87	3.84 (1.12)	2.46 (0.83)	2.63 (0.95)	8.1 (2.47)^B	71.21 (10.67)^B
	P value	-	0.082	0.07	0.655	0.000^b	0.000^b

The nasopalatine canal dimensions in sagittal section according to the general, gender, age groups and dental status
^aStatistically significant at level P ≤ 0.01 (independent samples Mann-Whitney U test).
^bStatistically significant at level P ≤ 0.01 (independent samples Kruskal-Wallis test).
^cStatistically significant at level P ≤ 0.05 (independent samples Kruskal-Wallis test).
The uppercase superscript indicates statistical differences within column (Dunn-Bonferroni post hoc analysis).
IF = incisive foramen; MP = mid-level point; SF = stenson foramen; NPC = nasopalatine canal; SD = standard deviation.