Prevalence and morphology of lower second molars with C-Shaped canals: A CBCT analysis

This study aimed to assess the prevalence and morphology of lower second molars with C-shaped configuration among patients at the University of Barcelona Dental Hospital using cone beam computed tomography (CBCT).

CBCT images of 408 patients, comprising 792 lower second molars, were examined to identify C-shaped canals and evaluate their anatomical characteristics. Inclusion criteria required patients to have both lower second molars present. The configuration of C-shaped canals was categorised at three axial root levels. The variables of symmetry, position, gender and age were analysed.

Out of the 792 lower second molars analysed, a total of 65 molars with C-shaped canals were identified in 42 patients, representing a prevalence of 10.2%. The prevalence in females (12.6%) was significantly higher than in males (6.5%). Bilaterality was observed in 54.76% of individuals with C-shaped molars. The C1 configuration was most frequently observed in the coronal third (56%), while the C2 configuration was equally distributed between the coronal and middle thirds (44.1%). The C3 configuration was most prevalent in the middle third (41.4%), and the C4 configuration was predominantly observed in the apical third (96%). Variations in configurations along the root were observed in 70.8% of the molars. The longitudinal groove was predominantly located on the lingual surface of the roots (83.1%).

CBCT is a useful tool to analyse the morphology of the root canal system. Key words:C-shape, anatomy, prevalence studies, root canal, Cone beam computed tomography, mandibular second molar.