•Purpose: to review and discuss the etiology, incidence, anatomic features, classification, diagnosis and
management of the C-shaped canal configuration.
Manual and electronic searches of literature were performed from 1979 to 2012¬ in Pub Med by crossing the keywords: Cshaped canals¬ mandibular second molar¬ mandibular first premolar¬ root canal morphology.
•Most highlighted Results:
•First Described by Cooke and Cox .
•Etiology: The failure of fusion of Hertwig’s epithelial sheath. (genetic origin)
•Incidence: higher in Asian population and in mandibular 2nd molar. •Anatomic features:
–Roots: conical or square configuration – Fusion labially or lingually of the mesial and distal roots- Occluso-apical groove on the buccal or lingual surface.
–Pulp chamber: Low bifurcation and connecting slit.
–Root canal system: C-shaped canals shows broad, fan-shaped communications from the coronal to the apical third of the canal. Accessory and lateral canals, inter-canal and apical delta can be found in (11-41%), in the apical region of C-shaped canals.
Numerous classification (Figure 1), earliest by Manning and Melton et al. (only the appearance of the canal orifices.
-RG characteristics: Radicular fusion- radicular proximity- a large distal canal or a blurred image of a third canal in between.
-Pre clinically: A longitudinal groove on lingual or buccal surface may predispose the tooth to localized perio disease (first indication).
-Access: Fan et al, features: Fused roots, a longitudinal groove, at least 1 cross-section of the canal belong to the C1, C2, or C3 configuration. (figure 2)
•Management: Careful location and negotiation of the canals and the meticulous mechanical and chemical debridement of the pulp tissue should be carried out in order to successfully treat a C-shaped canal.
Knowledge of the C-shaped canal configuration is essential to achieve success in endodontic therapy.