Application of tpsDig2 Software in Nasal Angle Measurements

J Craniofac Surg. 2020 Jan/Feb;31(1):319-325. doi: 10.1097/SCS.0000000000006024.

Abstract

Introduction and objectives: Nose is considered to be a conspicuous feature of human face. Its different parameters like shape, size, nasal angles etc may indicate one's gender, age, race, adapted climatic conditions, and the environment to which one belongs to. Furthermore, it is an important component and determinant of an individual's physical outlook and appearance. The current study provides a new approach for the assistance of anthropologists and forensic experts in human identification and sex determination from the nasal angles.

Methodology: The study was performed on a total of 500 subjects (250 males and 250 females) belonging to north India (Mandi, Himachal Pradesh State). In comparison to the classical and manual methods for nasal angle measurements, an automated approach was followed in the present study. A Windows-based software called tpsDig2 was used for nasal angle measurements by utilization of the landmarks (nasion, pronasale, subnasale, and alare). Three nasal angles (nasal prominence angle, inter-alar angle, and nasal tip angle) were measured in all the subjects and each measurement was repeated thrice to reduce the measurement error and increase the specificity and efficiency of the results. Discriminant function statistics was used for determination of sex from different nasal angles.

Results and conclusion: The results of the statistical analysis (ANOVA) performed using SPSS reveal the significant difference between males and females in all the 3 repeated measurements of nasal angles. The final discriminant classification statistics show that 64% of original grouped cases have been correctly classified and the designed statistical model can be used in several forensic scenarios for the sex determination on the basis of the available nasal angles. The study may be further useful in the identification cases pertaining to facial reconstruction. The investigation may also be helpful in providing specific correlation of the nasal angles with the other parts of the face in the cases of remodelling and reformation of craniofacial alterations and reconstructions in plastic surgery and aesthetics.

MeSH terms

  • Adolescent
  • Adult
  • Discriminant Analysis
  • Female
  • Humans
  • Male
  • Nose / anatomy & histology*
  • Software*
  • Young Adult