Relationship between root canal merging and presence of C-shaped canal in fused rooted maxillary molar teeth

Abstract

Objective: This study aimed to evaluate the prevalence of root fusion and the incidence of C-shaped canals inmaxillary first molar (MFM) and maxillary second molar (MSM) teeth using cone-beam computed tomography.Material and Methods: In this study, a total of 1233 MFMs and 1406 MSMs from 802 patients were analyzed.First, the number of fused rooted teeth and the type of root fusion were determined. Subsequently, incidenceand number of C-shaped canals were ascertained according to the type of fusion, location, position, and levelof canal merging in teeth with fused roots. Six types were established according to the C-shape configurationsobserved. Presence of root fusion and the C-shaped canal according to gender, age, and tooth position wereevaluated by chi-square test. Values with p< 0.05 were considered significant in statistical tests. Results: Theincidence of fusion in the MFM and MSM teeth was 6.16% and 22.40%, respectively. Only three MFMs (0.24%)and 3.77% of the MSMs had C-shaped canals. While the incidence of fusion was higher in women (p< 0.05),the C-shaped morphology was not affected by sex (p> 0.05). Individuals over the age of 50 years had a lowerincidence of C-shaped canals (p< 0.05). Conclusion: C-shaped canal morphology was more commonly associatedwith complex types of root fusion involving three roots; 16.83% of MSMs with fused roots had C-shaped canals.KEYWORDSCanal merging; Cone-beam computed tomography; C-shaped root canal; Root canal anatomy; Root fusion.