The Determination of Sexual Dimorphism Among the South Indian and North Indian Populations Using Nasal Index – an Anthropometric Analysis

Abstract

Anthropometry provides quantitative measurements of human body structures and can be used to describe variation within defined study populations. This study evaluated nasal height, nasal breadth, and nasal index among 200 participants, comprising 100 South Indian participants and 100 North Indian participants, with 50 males and 50 females in each regional group. Participants were aged 18–90 years. Nasal breadth and nasal height were measured using a digital vernier caliper, and nasal index (NI) was calculated as nasal breadth/nasal height × 100. Descriptive statistics and independent-samples comparisons were used to examine differences between sexes within each regional group and between the regional groups. The reported nasal-index means were 74.588 ± 8.86 for South Indian males and 70.912 ± 9.41 for South Indian females; the corresponding North Indian means were 70.098 ± 8.78 and 69.08 ± 8.61. Based on the reported summary statistics, the sex difference in nasal index was statistically significant in the South Indian group but not in the North Indian group. The regional difference in mean nasal index should therefore be interpreted as population-level or regional variation rather than as evidence of sexual dimorphism. The pooled descriptive means were approximately 72.75 for South India and 69.59 for North India. Mesorrhine was the most frequent nasal-index category in South India, whereas Leptorrhine was the most frequent category in North India. These findings provide descriptive baseline information for the study populations and may be relevant to clinical, anthropological, and forensic research; however, the nasal index alone should not be interpreted as sufficient to determine an individual's sex, race, ethnicity, or geographic origin.