Unmasking the Hidden Complexity of Mandibular Premolars: A Case Series on Navigating Root Canal Variations in Endodontics

Mandibular premolars are often perceived as straightforward in endodontic therapy due to their typically single-rooted anatomy. However, an increasing body of evidence reveals significant variations in their root canal morphology, posing diagnostic and therapeutic challenges for clinicians. These anatomical anomalies, including multiple canals, bifurcations, and atypical curvatures, may lead to missed canals, inadequate debridement, and ultimately treatment failure if not properly identified and managed. This case series showcases three cases exhibiting the types of root canal variations in mandibular premolars, emphasizing the importance of advanced diagnostic tools such as cone-beam computed tomography (CBCT), enhanced magnification, and illumination. The first case, a 44-year-old woman, exhibited two roots and three canals in both premolars, confirmed by CBCT imaging. Treatment involved rotary instrumentation, heated sodium hypochlorite irrigation, and obturation with bioceramic sealers under magnification. The second case featured a 33-year-old man with a previously initiated treatment in tooth #35. Enhanced visualization under the dental microscope revealed three separate canals, which were disinfected and obturated using a single-cone technique. The third case involved a 27-year-old woman whose premolar had a Type II configuration, with canals merging apically. Careful negotiation and sealing were performed under magnification. These cases highlight that combining CBCT, magnification, and contemporary obturation materials is essential for effectively managing complex premolar anatomies and achieving predictable outcomes. The study also explores contemporary shaping, cleaning, and obturation techniques tailored to complex canal systems. By integrating anatomical knowledge with evolving clinical strategies, endodontists can enhance the success of treatment outcomes in these deceptively complex teeth.