Association among the morphological characteristics of the human ear – An approach towards forensic identification

Introduction and objectives: The human external ear has intricate anatomy due to the presence of elevated and depressed structures which form the morphological characteristics of the external ear. It has been observed that they have some form of interdependence. Therefore, the present study is aimed to investigate the association amongst the morphological characteristics of the external ear and its feasibility for forensic identification. Material and methods: A cross-sectional sample of 497 participants (233 males and 264 females) aged 18–35 years (24.42 ± 5.17) was taken for the study. The data was collected from the district Solan of Himachal Pradesh, North India. Both the ears of the participants were examined for various morphological characteristics. The shape of the external ear, the contour shape of the supero-anterior, superior and supero-posterior helix, and other morphological characteristics were analyzed and classified based on the shape, rolling, contour shape, the strength of the elevated structures, and other factors. The associations between the morphological characteristics were investigated using chi-square and correspondence analysis, while Cramer’s V test was used to determine the strength of the association. Results: A total number of 33 morphological characteristics were considered for the present study. Each morphological characteristic was compared with the other 32 parameters. Therefore, a total number of 1056 (33 ×32) pairs were examined, with only 587 pairs showing a statistically significant association. The shape of the external ear, for example, has a significant association with 25 out of 32 morphological characteristics, including rolling of the superior and posterior helix, the contour shape of the supero-anterior, superior, supero-posterior helix, etc. Moreover, all the statistically significant pairs were subjected to correspondence analysis to evaluate the measure of their association. Wide rolled superior helix, for example, is closely associated with a round-shaped external ear, implying that if a person has a wide rolled superior helix, he or she is more likely to have a round-shaped external ear. Conclusion: The present study has explored and developed the database of the association of the morphological characteristics of the external ear. The database may be useful in predicting the shape and size of the external ear from some of these characteristics. The findings could be utilized during facial reconstruction in forensic examinations and the reconstruction of deformed ears. This study, therefore, finds that the morphological features of the ear are an important addition to the arsenal of the forensic investigator.