Prevalence and Anatomical Characteristics of C‐Shaped Canals in Mandibular Molars in Chile: A Nationwide Multicentre Cross‐Sectional Study
Fernando Peña‐Bengoa, Pablo Betancourt, Jaime Abarca, Carolina Cáceres, Patricio Meléndez, Claudia Valenzuela, Karin Steinfort, Nicolás Dufey‐Portilla, Jorge N. R. MartinsABSTRACT
This retrospective multicentre cross‐sectional study aimed to determine the prevalence and characteristics of C‐shaped canals in Chilean mandibular molars using cone‐beam computed tomography (CBCT) and to assess associations with demographic and geographic variables. A total of 5660 mandibular molars from CBCT scans obtained from imaging centres across different regions of Chile were analysed. External root morphology was categorized according to root fusion, and C‐shaped canals were classified using Fan's classification at five axial levels. The prevalence of C‐shaped canals was 9.88%, with most cases occurring in mandibular second molars (93.92%) and bilateral occurrence observed in 53.87% of affected individuals. Their distribution differed significantly across geographic regions ( p = 0.002). Regression analysis accounting for within‐patient clustering showed that female sex was significantly associated with their presence (OR = 1.74), whereas age showed no significant association. All C‐shaped canals showed root fusion. These findings provide population‐specific data for improving diagnostic accuracy and endodontic treatment planning.