Variability in human external ear anthropometry- Anthropological and forensic applications

Area of Science:

• Forensic Anthropology
• Human Anatomy

Background:

• The human auricle possesses unique morphological characteristics valuable for forensic identification.
• Ear morphology, including features like Darwin's tubercle and variations in helix and lobule, is utilized in criminal investigations.
• The ear's accessibility and its variations across sex, sides, and populations make it a subject of anthropometric study.

Purpose of the Study:

• To investigate sexual dimorphism and bilateral differences in the morphometry of the human ear.
• To establish a database of anthropometric variables for the human ear in a North Indian population for forensic and anthropological applications.

Main Methods:

• Anthropometric measurements of the human ear were taken from 140 individuals (71 males, 69 females) aged 18-30 years in North India.
• Linear measurements included ear length, ear breadth, and distances related to tragus, antihelix, and helix, along with lobule dimensions.
• Statistical analyses, including t-tests, Mann Whitney U, and discriminant function analysis, were employed to evaluate sex and bilateral differences and predict sexual dimorphism.

Main Results:

• Significant sex differences (p<0.05) were observed in physiognomic ear length, breadth, ear length above tragus, and distances from tragus to antihelix and helix on both sides.
• Significant bilateral differences (p<0.05) were found in most ear measurements for males, and for specific measurements (ear length above tragus, tragus to helix distance, lobule width) in females.
• The discriminant function model achieved 82.10% accuracy in determining sexual dimorphism.

Conclusions:

• The study confirms the presence of sexual dimorphism and bilateral variations in human ear morphometry within the studied North Indian population.
• The collected anthropometric data provides a valuable resource for forensic and anthropological identification purposes.
• Ear morphometric analysis offers a reliable method for individualization in forensic science.