The a-b Dermatoglyphic Ridge Breadth: An Indication of Developmental Significance

The purpose of this study was threefold: to present a-b ridge breadth data on various populations; to synthesize factors influencing the a-b ridge breadth; and to suggest areas of developmental significance which are important in the a-b ridge breadth determination. The a-b ridge breadths of ten sample groups representing Whites, Blacks, Amerindians, and Indians were collected and determined.

The mean a-b ridge breadths were determined for each of the ten sample populations. These a-b ridge breadths were compared with previously published a-b ridge breadth data. The primary procedure used in data analysis was analysis of variance (ANOVA). The groups were further divided to determine differences between sexes. An F ratio was calculated for both the males and the females to determine if there were significant differences in a-b ridge breadths.

The major findings of the research were that the differences in the mean a-b ridge breadths of the ten populations were significant. These results agreed with other studies of the a-b ridge breadths. It appears that there are differences between sexes when the a-b ridge breadths are compared. Ridge breadth was found to indicate significant group differences. Additionally, there was noted a geographic patterning of ridge counts and ridge distances. The a-b ridge count was found to be the one factor that varied between groups with consistency.

The developmental significance of the a-b ridge breadth was further highlighted by this study. It was previously known that the ridges of the palms are a record of the developing fetus. However, the exact nature of the record which is marked on the palms is unclear. It was perceived through this research endeavor that the actual width of the dermatoglyphic ridges in the a-b palmar area was the aspect of the a-b ridge breadth which illustrates developmental significance.

Systematic population comparisons were proposed in this study to help illustrate the aspects of palmar dermatoglyphics which are affected during development. More diverse sample populations need to be included in future studies. With more populations being examined for differences in palmar dermatoglyphics, the developmental significance of the a-b ridge breadth will be better understood.