Posterior tooth morphology and lower incisor crowding

Abstract

Frequently, only the mesiodistal dimensions of mandibular posterior teeth have been investigated in relation to lower incisor crowding. The aim of the present study was to investigate any relationship between lower incisor crowding and mesiodistal widths, buccolingual dimensions, occlusal area and occlusal perimeter of mandibular posterior teeth. Mandibular dental casts of 50 Caucasians (25 males and 25 females) were used. Mesiodistal widths, buccolingual dimensions, occlusal area and occlusal perimeter were measured using image analysis techniques. Lower incisor crowding was determined using (1) Little’s irregularity index and (2) anterior-tooth size arch length discrepancy. Using Pearson correlation, the occlusal area, perimeter, mesiodistal widths and buccolingual dimensions of the lower first molar were significantly, positively correlated with Little’s irregularity index. The significant correlation between occlusal area and crowding did not appear to be secondary to larger mesiodistal widths.