No correlation between sexually dimorphic ratios of the sizes of fourth to second digits and hypothesized ratios of the sizes of the central to lateral incisors

Abstract

Abstract Aim: Following the fourth to second digit ratios being used as a marker of sexual dimorphism and the embryogenetic hormonal origin in common with the permanent dentition, the aim of this study was to determine if a homologous ratio existed for the central and lateral incisors which correlated with the digit ratios. Materials and Methods: Bilateral linear lengths in millimeters of fourth and second digits (reversed for clearer analysis) were obtained using vernier calipers from standardized photocopies of the ventral palmar surfaces of 61 male and 51 female (n = 112) volunteer dental students, the ratios of which were correlated with the ratios of the linear measures (mm) of the inciso-cervical (IC) and mesiodistal (MD) measurements of their central to lateral incisors. Results: Dimorphic digit ratios were comparable with those of other investigators, with male digits and incisors significantly larger than females (p < .001). Although both male maxillary incisors, IC and MD, were significantly larger than females, the ratios unexpectedly were not, with only a limited number of low but significant correlations with the digit ratios. Conclusions: While there were only a limited number of significant sexually dimorphic correlations between the digit and incisor ratios for non-White participants, the results obtained suggest further investigation of possible relationships between the sexually dimorphic digit ratios and odontometric ratios other than central to lateral incisors.