Accuracy in measurement of facial index on the basis of an android application

Objectives The Prosopic index or Facial index is an important measurement, required to be taken during the orthodontic diagnosis phase. Classification of faces into broad, average, or narrow not only allows comprehensive orthodontic treatment planning based on aesthetics and facial form, but could also be used in other fields such as anthropology and forensic medicine. The authors have developed a photographic app for AndroidOS that will enable easy classification of the face into different facial types as given by Banister. The aim of this study is to compare the findings of the facial index of a sample of randomly selected subjects derived from the application with findings of the same subjects derived manually, to check for the accuracy of the new technology. Material and Methods The measurements of facial index derived from this app were compared to the facial index of a sample of Indians derived manually (using an independent t-test). Inter-examiner reliability of the measurements by three different investigators on the same sample was tested using Cronbach’s alpha. A Chi-square test was used to compare the Prosopic index based on the method of determination. Results There was no significant difference between the values of facial index generated from the app compared to those derived manually. The Cronbach’s Alpha value derived was 0.998, indicating the best agreement between examiners. Maximum subjects showed a hyperleptoprosopic facial phenotype in both the app and manual methods. Conclusion The app, utilizing a smartphone, enables quick and reliable measurement of the Facial Index without the need for equipment like calipers or calculations.