Sexual dimorphism of the index to ring finger ratio in South Indian adolescents.

Sex determination from prepubertal human remains is a challenge for forensic experts and physical anthropologists worldwide as definitive sexual traits are not manifested until after the full development of secondary sexual characters that appear during puberty. The research was undertaken in 350 South Indian adolescents to investigate sexual dimorphism of the index and ring finger ratio. The index finger length (IFL) and the ring finger length (RFL) were measured in millimeters in each hand and the index and ring finger ratio was computed by dividing the index finger length by the ring finger length. Mean RFL was greater than mean IFL in both males and females. Mean RFL was significantly higher in males. The index and ring finger ratio showed a statistically significant difference between males and females (p </= 0.001). The index and ring finger ratio was found to be higher in females (0.99) when compared to their male counterparts (0.95). The index and ring finger ratio thus shows sexual dimorphism in the South Indian adolescents that may prove useful to determine the sex of an isolated hand when it is subjected for medicolegal examination. The study suggests that a ratio of 0.97 and less is suggestive of male sex, while a ratio of more than 0.97 is suggestive that the hand is of female origin among South Indian adolescents. Copyright 2010 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.