What is a radix root?

Radix root is a term for an extra distal root on a lower molar tooth.

missed canal radix root root canal — If you only take a single PA you can miss the root like this case. If the final PA was at the same angle this root canal was going to be a failure do to missing that root.

What is the research on radix roots?

The radix root is much more prominent in the Asian population. Less than 1% of Venezuelans have one but 22% of Chinese have one. Martins JOE 2022

Korean study March 2012 Stats show Koreans have high rates and high rate of consistency between bilateral sides. They have a correlation with complex root canal configuration of mandibular 1st premolar. Wu JOE 2017

2R2C 23%
1R1C 4%
bilateral 2R2C was 18%
bilateral 1R2C was 3%

Korean population study Kim 2013 JOE Dec shows 3/4 have 2 roots, 1/4 have 3 roots – 50% have 4 canals.

Other examples of radix root cases

The radix root is not that uncommon so not going to show a lot of them. We currently take CT on all molars getting a root canal but prior to that it was much likely to miss one due to angle of the x-ray. The treatment of these roots is not difficult when you know it’s there. They are straight forward single canal roots.

The case in this link shows a pretty typical one.

For more information on the anatomy of lower molars you can check out our page on lower molar root canal anatomy. The page is heavy on studies and is for professionals not patients.