A cone-beam computed tomography study of C-shaped root canal systems in mandibular second premolars in a Taiwan Chinese subpopulation

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

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.

Prevalence and correlation of C-shaped root canals of mandibular premolars and molars in Eastern Chinese individuals

The aim of this study was to investigate the prevalence, correlation, and differences of C-shaped root canals (CSRCs) morphology in permanent mandibular premolars and molars in Eastern Chinese individuals using cone-beam computed tomography (CBCT). A total of 8000 mandibular first premolars (MFPs), mandibular second premolars (MSPs), mandibular first molars (MFMs), and mandibular second molars (MSMs) CBCT images from 1000 patients (692 females and 308 males) were collected. The prevalence, correlation, bilateral/unilateral presence, the morphology of CSRCs, level of canal bifurcation, gender differences, and location of radicular grooves (RGs) were evaluated. The prevalence of CSRCs in MFPs, MSPs, MFMs and MSMs were 10.25%, 0.25%, 0.55% and 47.05%, respectively. The prevalence of CSRCs in MFPs of males was higher than that in females, while the prevalence of CSRCs in MSMs of females was higher than that in males (P < 0.05). The bilateral symmetry presence of CSRCs in MSMs was significant but not in MFPs, MSPs, and MFMs. RGs were predominantly found on the mesiolingual (ML) surface of premolars and the lingual surface of molars. There was a high prevalence of CSRCs in MFPs and MSMs in the Eastern Chinese population, but there was no correlation. The prevalence of CSRCs in MFPs and MSMs differ significantly by gender (P < 0.05).

Prevalence of complex root canal morphology in the mandibular first and second premolars in Thai population: CBCT analysis

Background

Mandibular premolars demonstrate high variability in root canal morphology, especially mandibular first premolars. The purposes of this study were to determine the prevalence of root canal configurations of mandibular premolars according to Vertucci classification in a Thai population.

Methods

Total of 1159 CBCT images of Thai patients who received radiographic imaging at the Department of Radiology, Faculty of Dentistry, Chulalongkorn University in 2017–2018 was evaluated. The data were reported using descriptive statistics and the relationship between the prevalence of the root canal complexities and sex was analyzed using the chi-squared test.

Results

The most common root canal configuration was Vertucci type I, with a 63.1% and 98% prevalence in the mandibular first and second premolars, respectively. More than 98% of mandibular premolars had a single root. The prevalence of a bifurcation was 28.5% and 1.5% in the mandibular first and second premolars, respectively. The prevalence of a trifurcation was 3.2% in the mandibular first premolar. A C-shaped root canal was observed at 23.7% and 0.7% in the mandibular first and second premolars, respectively. The level of branching was mostly found at the middle 1/3 of the root. Bilateral appearance of the same root canal configuration was identified in 80.3% and 95.9% in the mandibular first and second premolars, respectively. There was no relationship between sex and the prevalence of a bifurcation, trifurcation, or C-shaped root canal.

Conclusion

Mandibular first premolars have more root canal complexities than mandibular second premolars. Horizontal tube shift x-ray technique, CBCT, dental operating microscope, and knowledge of root canal configurations have an important role in root canal identification in mandibular premolar with suspected complex root canal morphology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01822-7.