Defense Date


Document Type


Degree Name

Master of Science in Dentistry

First Advisor

Dr. Amber Ather

Second Advisor

Dr. Garry Myers

Third Advisor

Dr. Parthasarathy Madurantakam

Fourth Advisor

Dr. Caroline Carrico


Introduction: Premolars are especially challenging to treat endodontically due to their small size and often-intricate anatomy. While the majority of premolars present with one or two root canals, the presence of three root canals has been reported. The aim of this study was to investigate the correlation between the root-to-crown width ratio (RCWR) and number of root canals in maxillary and mandibular premolars.

Methods: Data was retrieved from the electronic health records of patients treated at Virginia Commonwealth University School of Dentistry. A total of 100 premolars which had both periapical radiograph (PA) and cone beam computed tomography scans (CBCT) were identified and used for this study. The maximum mesial-distal crown width (MCW) and the widest mesio-distal width of the root (MRW) of each premolar were measured by two examiners using both PAs and CBCTs. The root-to-crown width ratio (RCWR) was calculated by dividing the MRW by the MCW. Statistical analysis was performed to determine the correlation between RCWR and the number of root canals as confirmed by CBCTs.

Results: Premolars with three root canals had a RCWR significantly higher than premolars with one or two root canals (p<0.0001). Based on the logistic regression model, RCWR of at least 0.83 as determined from a PA or RCWR of at least 0.70 from a CBCT were associated with three root canals (predicted probability of 90%).

Conclusion: A larger root-to-crown width ratio (RCWR) indicates a significantly higher probability of three root canals in maxillary and mandibular premolars.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission


Available for download on Tuesday, April 23, 2024