The “C” in Complexity - A Case Series on Navigating Fan’s Classification of C-shaped Canals

Sep 30, 2026

Uploaded by Stanley

C-shaped canal anatomy is most commonly found in mandibular second molars, and its complex ribbon-shaped configuration, transverse anastomoses, fins, and webs make endodontic negotiation, debridement, and obturation challenging. Radiographic and clinical assessment enables identification and targeted management of Fan-based C-shaped classifications. Root canal configuration knowledge is essential to achieve success. This case series documents four different cases categorized using Fan’s classification, and all achieved positive outcomes with specific protocols and modified obturation techniques.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Abstract

Introduction

Case Presentation

Case Report

Review began 11/07/2025 Review ended 12/05/2025 Published 12/08/2025 © Copyright 2025 Rawal et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0. , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited. DOI: 10.7759/cureus.98699 Open Access Case Report The “C” in Complexity: A Case Series on Navigating Fan’s Classification of C-shaped Canals Aabha B. Rawal 1 , Dhaval V. Desai 2, Riddhi V. Doshi 3 , Hetvi K. Bhuva 4 1. Conservative Dentistry and Endodontics, Government Dental College and Hospital, Jamnagar, IND 2. Conservative Dentistry and Endodontics, Faculty of Dental Science, Dharmsinh Desai University, Nadiad, IND 3. Conservative Dentistry and Endodontics, Private Practice, Ahmedabad, IND 4. Public Health, Reflections Dental Care, Brooklyn Park, USA Corresponding author: Aabha B. Rawal, [rawalaabha3@gmail.com](rawalaabha3@gmail.com) Abstract C-shaped canal anatomy is most commonly found in mandibular second molars. The complex anatomy can be challenging to the clinician during negotiation, debridement, and obturation. The fan-shaped regions, transverse anastomoses, fins, and webs ofthe C-shaped anatomy can be identified and treated with the help of radiographic and clinical diagnosis. Adequate knowledge of the root canal configuration is essential to achieve success in endodontic therapy. This case series highlights the management of four different cases of C-shaped canal configurations categorized on the basis of Fan 's Classification. Despite the significant challenges, a positive outcome was achieved in all the cases through specific protocols and modified obturation techniques. Categories: Dentistry Keywords: c-shaped canal configuration, endodontic treatment, fan 's classification, root canal anatomy, themoplasticized obturation Introduction A good understanding of the root canal anatomy is essential for the success of root canal therapy. The root canal anatomy of the mandibular second molars varies greatly. The root canal system 's "C " configuration is the most prevalent among them, which was first reported by Cooke and Cox in 1979 [1] . Manning [2] proposed that the main reason for the C canal configuration might be the inability of Hertwig 's epithelial root sheath to fuse onto the buccal or lingual root surface. Instead of having multiple distinct orifices, this form of canal arrangement has a single ribbon-shaped orifice that resembles a 180° arc that begins at themesiolingual line angle and arcs across the buccal to the distal side. The two main variations are (a) a single, ribbon-like, C-shaped canal that extends from the aperture to the apex and (b) three or more separate canals that emerge beneath the C-shaped orifice [3] . With a prevalence ranging from 2. 7% to 44.5%, the C-shaped variations were most frequently found in mandibular second molars [4] . Additionally, maxillary first molars (0 . 12%), maxillary third molars (4 . 7%), mandibular third molars (3 .5-4%), and mandibular second premolars (1%) have also been observed to have"C " shaped canals [5] . It is not associated with gender, age, or tooth position. However, ethnic predilection is noted, with the highest incidence reported in East Asian population groups such as Chinese (29 . 7%) and Koreans (31 .3%-45 .5%) [6] . Various classifications have been published to make it easier to diagnose and treat variations of C-shaped canals. Melton [7] divided them into three groups based on their cross-section: continuous C-shaped, semicolon-shaped, and two or more distinct canals. Fan et al. [8] later modified this classification, as the main drawback of Melton 's Classification was that there was no clear description of the difference between categories C2 and C3. Four distinct C-shaped canal configurations in mandibular second molars, classified from C-1 to C

FAQs

Where are C-shaped canals most commonly found?

C-shaped canal anatomy is most commonly found in mandibular second molars.

Why is managing C-shaped canals challenging in endodontic therapy?

The complex anatomy, including fan-shaped regions, transverse anastomoses, fins, and webs, can make negotiation, debridement, and obturation difficult.

How many cases are presented, and how are they categorized?

The case series presents four different cases categorized based on Fan’s classification of C-shaped canal configurations.

Sep 30, 2026

Uploaded by Stanley