Morphometric Analytical Study of External Nose Angulations Using Photographic Technique to Derive Reference Values for Sex and Ethnic Group Differentiation in Forensic Identification

Abstract

Background: Shape of the nose is unique with regard to ethnicity, race, and sex. Therefore, determining external nose angles provides norms for ethnic and racial differences. Prime objective of the present study was to describe the external nose angulations of Medical students of Tamil Nadu origin (representing South Indian population). Methods: The present cross-sectional study was done on 118 Medical students from Velammal Medical College Hospital and Research Institute, Tamil Nadu Dr. M.G.R. Medical University, Chennai. Consenting students of Tamil Nadu origin were included. Individuals, other than Tamil Nadu origin, or with noticeable facial disfigurement, or with history of previous facial surgery were excluded. Sample size was calculated using Sample Size Calculator presented as a public service of Creative Research Systems: Survey software, ‘The Survey System’. Results: It was found that the angles were more obtuse in females compared to male counterparts, except for nasofacial and nasomental angles. Based on linear regression graph plotting, low positive correlation was seen to exist between nasal tip and nasolabial angles. However, low negative correlation was found between nasofacial and nasal tip angles. Also, the results were significant with nasofrontal, nasal tip, and nasolabial angles in differentiating gender, i.e., significant difference exists between male and female participants in relation to these angles. Conclusion: Nasofrontal, nasal tip, and nasolabial angles are useful parameters in differentiating individuals based on gender and ethnicity. These angles differed significantly amongst the gender groups in the present study.