Score Group 1
(n = 74)
Group 2
(n = 76)
Group 3
(n = 72)
Coronal third 1 60a 58a 58a
2 6a 6a 8a
3 4a 10a 2a
4 4a 2a 4a
Middle third 1 52a 48a 48a
2 8a 14a 8a
3 6a 8a 12a
4 8a 6a 4a
Apical third 1 8a 30b 30b
2 42a 40a 36a
3 20a 4b 4b
4 4a 2a 2a

Note: Different superscript letters indicate statistical significant differences (P < 0.05) among groups using the Kruskal-Wallis test and Bonferroni multiple range test for multiple group comparisons.