An epidemiological study of extracted mandibular premolars from adolescent patients in Damascus using two...

This study aimed to assess the root number, length, and root canal morphology of extracted mandibular premolars (MPs) from adolescents in Damascus using two classification systems: Vertucci's classification and Ahmed's classification. This was conducted through radiographic examination utilizing Cone Beam Computed Tomography (CBCT) and digital dental radiography analysis. Additionally, the study sought to investigate the correlation between these variables and gender within the sample.

Immediately after extraction, the root number and maximum length were recorded. Each MP was then radiographed in buccolingual and mesiodistal directions using digital periapical radiographs. Subsequently, MPs were scanned using a CBCT device (200 μm voxel size) and the root canal morphology was classified based on Vertucci's classification and Ahmad's classification based on both radiographs. Moreover, the presence of C-shaped canals was investigated and classified according to the Fan et al. classification. Finally, the previous findings were correlated with the patient's gender, and statistical analysis was performed using the Chi-Square test and T-test in the SPSS program. The confidence interval used for the Chi-square test was 95%. Moreover, the sensitivity, accuracy, specificity, and overall agreement tests was performed to compare digital sensor radiographs with the gold standard CBCT radiographs.

The sample included 255 first MPs and 163 s MPs. No significant differences were found between males and females regarding the frequency of one, two, or three roots in the first and second MPs (p = 0.931 and p = 0.010, respectively). Most MPs had a single root. The mean length of the first MP was 21.9 mm, and the second MP was 21 mm, with males generally having longer MPs than females (p < 0.001). There were no significant gender differences in the distribution of first and second MPs according to Vertucci and Ahmed classifications (p > 0.05). Type I (¹TN¹) was the most common root canal morphology, followed by Type V (¹TN^1-2). Low occurrence of C-shape canals was observed in first and second MPs (4.31% and 9.82%, respectively). The sensitivity, specificity, accuracy, and overall agreement between the two radiographic assessment techniques of both MPs were highly comparable.

It can be concluded that variations in root number and canal classifications are evident in MPs. Although gender does not influence the root number or canal morphology, males tend to have longer MPs. Moreover, it is noteworthy that digital sensors performed better in detecting small accessory canals in the apical third.