From: CBCT evaluation of root canal morphology and anatomical relationship of root of maxillary second premolar to maxillary sinus in a western Chinese population
Gender
Canal category
Type I
Type II
Type III
Type IV
Type V
Type VI
Type VII
Type VIII
Female
232 (54.7)
141 (33.3)
3 (0.7)
44 (10.4)
4 (0.9)
0
Male
384 (55.3)
216 (31.1)
3 (0.4)
70 (10.1)
13 (1.9)
5 (0.7)
1 (0.2)
2 (0.3)