C-shaped root canal configuration in maxillary first molars.

AIM: This clinical report presents the endodontic treatment of two maxillary first molars and the anatomical study of two additional maxillary first molars with a C-shaped distally located root canal system. This configuration is not a common finding.
SUMMARY: According to the endodontic literature, the C-shaped root canal is most frequently seen in the mandibular second molar. The occurrence of C-shapes in maxillary first molars, however, has only been described in a limited number of case reports. We observed this configuration in two out of 2175 root-filled maxillary first molars treated at the Department of Endodontology, Ghent University Hospital, during the last 10 years. In order to study and visualize this particular aberration, cross-sections in two additional two-rooted maxillary first molars were made. From these cross sections it can be concluded that the C-shaped canal configuration is the result of a fusion of the distobuccal and the palatal roots.