Table 3. Radiographic sign scores of three groups over the periods.

Time period	Radiographic sign score	Group I	Group II	Group III	χ2 value	p value
0 mon	1	25 (100.0)	25 (100.0)	25 (100.0)	NA	-
	2	0 (0.0)	0 (0.0)	0 (0.0)
	3	0 (0.0)	0 (0.0)	0 (0.0)
	4	0 (0.0)	0 (0.0)	0 (0.0)
3 mon	1	25 (100.0)	23 (92.0)	24 (96.0)	3.08	0.544
	2	0 (0.0)	1 (4.0)	0 (0.0)
	3	0 (0.0)	1 (4.0)	1 (4.0)
	4	0 (0.0)	0 (0.0)	0 (0.0)
6 mon	1	20 (80.0)	16 (64.0)	18 (72.0)	13.11	0.041
	2	3 (12.0)	6 (24.0)	0 (0.0)
	3	2 (8.0)	3 (12.0)	4 (16.0%)
	4	0 (0.0)	0 (0.0)	3 (12.0)
9 mon	1	17 (68.0)	14 (56.0)	18 (72.0)	21.78	0.001
	2	6 (24.0)	6 (24.0)	0 (0.0)
	3	2 (8.0)	5 (20.0)	1 (4.0)
	4	0 (0.0)	0 (0.0)	6 (24.0)

The numbers in the parentheses were the percentages of the cases rated as the score.

NA, not applicable.