Iranian Endodontic Journal

Abstract

Introduction: Maxillary third molars have unpredictable anatomy, and no anatomical series has described them in Azerbaijani individuals. We aimed to describe their root and canal morphology in Azerbaijani men and to test whether root fusion relates to canal configuration. Materials and Methods: In this cross-sectional study, 450 consecutively extracted maxillary third molars from 417 men aged 18–40 years were stained with India ink, cleared, and examined under a stereomicroscope. We recorded root fusion, root length and curvature, canal number, Vertucci configuration (atypical patterns recorded separately), apical foramina, accessory canals, and isthmus. Associations were tested with chi-square or exact tests, and reliability with Cohen’s kappa (κ). Results: Teeth had one (46.2%), two (28.0%), or three roots (25.8%), and roots were completely fused in 58.2%. The longest root per tooth averaged 13.25±1.85 mm, with a median curvature of 14.8^°. Two or more canals were present at the apical third in 81.3%. Vertucci type I was the most common (26.2%), and 14.7% were atypical. More than one apical foramen occurred in 60.0%, accessory canals in 15.6%, and an isthmus in 12.7%. Inter-observer agreement for isthmus (κ=0.672) and accessory canals (κ=0.645) fell below the prespecified threshold (κ≥0.75), so these two estimates should be read with caution. Fusion pattern showed a weak, borderline association with tooth-level Vertucci configuration (exact P=0.048; Cramér’s V=0.171), with type I least common in completely fused roots. Isthmus was not significantly associated with configuration (exact P=0.169). Conclusion: Root fusion showed a modest, borderline association with canal configuration, which should be treated as exploratory because it was not adjusted for multiple comparisons. Findings from extracted teeth may not apply to living patients.