Studies on Anatomy Mandibular Premolar

C shaped premolar image

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

root canal anatomy mandibular premolar c-shape canal

C-shape premolar 20% Chinese popualtion micro-CT – Buccal always main canal so be careful on lingual so don’t perf Gu 2013

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

CBCT Chinese study Yang 2013

  • 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