Interrelationship between anatomical variations in mandibular teeth: a cone-beam computed tomography (CBCT) based...

This retrospective study evaluated the anatomical variations and morphological interrelationships of mandibular anterior, premolar, and first molar (MFM) teeth in a Turkish subpopulation using cone-beam computed tomography (CBCT), while categorizing and comparing root canal anatomies based on both the traditional Vertucci and contemporary Ahmed's classification systems. The study analyzed CBCT images of 9,504 mandibular teeth from 792 patients. Root canal configurations were classified utilizing both the Vertucci and Ahmed's systems. The study additionally evaluated root counts, distolingual root (DLR) presence in MFMs, bilateral agreement, and cross-group anatomical correlations. All anterior teeth were single-rooted but displayed significant internal morphological diversity. MFMs predominantly featured a two-rooted structure, with a DLR (Radix Entomolaris) observed in 5.3%-6.8% of cases. A significant positive correlation emerged between complex canal configurations in lateral incisors and the presence of an ipsilateral MFM DLR (p = 0.003, OR = 2.23). Males exhibited significantly higher anatomical complexity in premolars than females. Mandibular teeth demonstrate high morphological diversity and bilateral agreement. The statistically significant but weak correlation between lateral incisor canal complexity and MFM DLR presence may represent a preliminary indicator that requires further validation. Furthermore, the Ahmed's system provides broader descriptive coverage for for defining complex root canal anatomies compared to the traditional Vertucci classification.