Crown morphology and additional canals in mandibular incisors using cone-beam computed tomography: A geometric...

Mandibular incisors usually have a single root and canal, but additional canals may be present. Undetected canals can lead to endodontic failure.

This study evaluated whether tooth shape and dimensions can predict additional canals.

This study evaluated the relationship between crown shape, buccolingual (BL) width, and overall tooth dimensions in mandibular incisors using cone-beam computed tomography and two-dimensional geometric morphometry.

Coronal morphology was documented using TPSutil (version 1.83) and TPSdig2 (version 2.31) in teeth with single and bifid canals. Landmark coordinates were analyzed in MorphoJ (version 1.07a) using Procrustes superimposition.

Chi-square test, Procrustes analysis of variance (ANOVA), and discriminant function analysis (DFA) were used.

Of 108 teeth assessed, 52.7% (n = 57) had single canals (Type I), and 47.2% (n = 51) had additional canals (98.03% Type II and 1.96% Type IV). The first five principal component analysis components accounted for 82% of variation. DFA classified 64.7% of additional canal teeth and 63.1% of single canal teeth (63.9% accuracy). Maximum variation occurred at cervical crest curvatures, with lower incisal edges in additional canal teeth. Procrustes ANOVA showed no size differences (P = 0.7301).

Teeth containing additional canals displayed increased buccal and lingual crest widths and reduced incisal height compared to teeth with a single canal; however, the BL width differences were not statistically significant. Overall, crown dimensions did not show any meaningful association with the presence of extra canals in mandibular incisors.