[Sex Characteristics and Distribution of External Ear in Uygur Population of Xinjiang]

Objective To analyze the characteristics of the bilateral external ears of Uygur adults by directly observing the morphological characteristics of the external ears of Uygur adults and classifying each feature. The frequency distribution of the characteristics was calculated to provide reference for forensic identification. Methods The 210 cases （75 males and 135 females） of bilateral external ear photos of Uygur adults in Xinjiang that met the inclusion criteria were collected. The frequencies of the features of the external ear were recorded and distinguished between the two sexes and the different sides. The data were statistically analyzed by SPSS 21.0 statistical software. Results The shapes of the external ears of males and females were commonly oblique or rectangular （34.67% of the left external ear of males and 41.33% of the right were oblique; 30.37% of the left and right external ear of females were rectangular）, while triangular ears were the rare variants and the least common. Sex and bilateral differences were observed as regards the form of the helix in the subjects. Normally rolled helix was the most common （58.67% males and 61.48% females for the left ear; 60.00% males and 72.59% females for the right ear）. Wide covering scapha helix was the most rare for the male left ear and flat helix was the most rare for the female right ear. Square and free earlobes were the most common （49.33% males and 62.96% females for the left ear; 40.00% males and 54.81% females for the right ear）, whereas triangular earlobes were rarely seen. Single knob tragus （40.00% males and 37.78% females for the left ear; 37.33% males and 33.33% females for the right ear） and projection type of Darwin's tubercle （50.67% males and 40.00% females for the left ear; 48.00% males and 39.26% females for the right ear） were found to be common. Conclusion The characteristics of the bilateral external ears of male and female Uygur adults have differences, which can be used for forensic identification.