Prevalence and morphology of different root canal systems in mandibular premolars: a cross‐sectional observational study

Abstract

BackgroundThis 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.MethodsCBCT 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.ResultsA 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).ConclusionsThere was substantial variation in cross‐sectional anatomy within and between C‐shaped premolars, which will affect endodontic treatment planning. © 2023 Australian Dental Association.