Comparative evaluation of curvature severity of mesiobuccal canals in permanent maxillary 1st molar using multiple complexity risk criteria: A cone-beam computed tomography-based cross-sectional study of central Indian subpopulation

Aim: The study is aimed to evaluate the curvature severity in Mesiobuccal (MB) canals of permanent maxillary 1 st molars along sagittal and coronal planes using cone-beam computed tomography in a Central Indian subpopulation. Methods: In the Central Indian subpopulation, 300 untreated permanent maxillary first molars with single curvatures in sagittal and coronal planes were assessed to determine canal angle and radius ( r ). Curvature severity was classified using the Case Difficulty Assessment form proposed by the American Association of Endodontists, based on Schneider’s method. Curvatures were categorized as slight (<10°), moderate (10�–30�), and severe/extreme (>30�). Statistical analysis was performed using t -tests and Chi-squared tests, with significance set at P ≤ 0.05. Results: Moderate curvature was most prevalent in sagittal (58.7%) and coronal (59.7%) planes, followed by severe/extreme curvatures at 28.6% and 26.3%, and slight curvatures at 12.7% and 14.0%, respectively. A significant inverse relationship was noted between curvature severity and radius, with sharper curvatures showing reduced radii ( P < 0.001), reflecting increased biomechanical complexity. Conclusion: MB canals in this population predominantly show moderate curvature by Schneider’s method, indicating medium risk during endodontic procedures.