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Updated: Jul 11, 2025
Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Prevalence and morphology of different root canal systems in mandibular premolars: a cross-sectional observational
O Rae1, P Parashos1
1Melbourne Dental School, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Melbourne, Victoria, Australia.
Background:
This study investigated the prevalence and morphology of C-shaped and non-C-shaped root canal systems in permanent mandibular first (PM1) and second (PM2) premolars using retrospective analysis of cone-beam computed tomography (CBCT) scans, and panoramic radiographs.
Methods:
CBCT scans from 2000 patients were screened for the presence of premolars with C-shaped canals and then assessed at three axial levels to determine the canal classification. The teeth were also assessed for Vertucci configuration, number of roots, and radicular grooves. Pre-existing panoramic radiographs were evaluated to identify features specific to PM1/2 with multiple canals or C-shaped anatomy.
Results:
A total of 1576 PM1 and 1424 PM2 from 880 patients were evaluated. The overall prevalence of C-shaped canals was 2.2% (3.3% PM1, 1.0% PM2), with 49 (5.6%) patients presenting with at least one C-shaped mandibular premolar. There were 2.3 ± 0.6 and 2.4 ± 0.5 different classifiable cross-sections per tooth for PM1 and PM2, respectively. The sudden disappearance or bifurcation of a canal on panoramic radiographs was associated with the presence of multiple canals (P < 0.001) or C-shaped anatomy (P = 0.03).
Conclusions:
There was substantial variation in cross-sectional anatomy within and between C-shaped premolars, which will affect endodontic treatment planning. © 2023 Australian Dental Association.
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