Root canal Anatomy Mandibular Premolar
98% single root (1-4 present) 76% single canal 79% single apical foramen. Very high racial variances Cleghorn May 2007 Lit review
Second premolars are more likely to have 1 canal (nearly all) leaving the first premolar more likely to have 2 canals (22%). Three canals are very rare less than .5%. Bürklein JOE 2017
Worldwide study of mandibular premolars show 24% of first premolars have lingual canal and 5% of second premolars have lingual canal. Martins JOE 2021
American population sectioned teeth 73% type I 3% type III 24% type IV (actually all either type V or type VII) – 14% were C shaped – mostly type IV Baisden Oct 1992
2000 tooth study in Portugal found 2.6% first premolars have C-shape and .6% of second premolars have C-shape Martins JOE 2017
C-shape premolar 20% Chinese popualtion micro-CT – Buccal always main canal so be careful on lingual so don’t perf Gu 2013
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| 2:2:1 ratio of A:B:C |
Single canal 54-88% Multiple 11.5-46% with Type V being most common Xiangje Li March 2012
- 77% 1 canal
- 22% 2 canals type II to V
- 1% C shaped
- <1% type VIII
3x view only of sectioned teeth India Singh 2014 JOE
