As clinicians, we must be aware of the variations that are possible in root canal anatomy.  There have been many studies that have attempted to classify these variations and one of the commonly sited papers is Vertucci et al. 1984.  The following is a diagrammatic representation of Vertucci’s canal configuration:

 

(Adapted from Vertucci 2005)

We all know that maxillary 1^st premolars tend to be quite narrow mesio-distally and have slender roots, which can pose both restorative and endodontic challenges.  The following are a few examples of variations in root canal anatomy in 1^st premolars that I have managed recently.  A thorough preoperative radiographic assessment and careful visual examination upon endodontic access are critical in locating all the canals! 

Two canals in two roots (Type I)

 

Two canals in one root (Type II)

 

Two canals in one root (Type IV)

Three canals in three roots (Type I)

 

 

 

 

 

Dr. Michael Yoon