From: Prevalence of complex root canal morphology in the mandibular first and second premolars in Thai population: CBCT analysis
Tooth
Level
Coronal 1/3 n (%)
Middle 1/3 n (%)
Apical 1/3 n (%)
Mandibular 1st premolar
33 (15.3)
163 (75.5)
20 (9.3)
Mandibular 2nd premolar
2 (20)
5 (50)
3 (30)