Abstract
External ear anthropometry has been used as an indicator of some congenital anomalies and other disease conditions. However, its application in assessment of anthropometric indices of adiposity such as body mass index received less attention especially among Hausa ethnic group of Nigeria. The objectives of the study were to (i) evaluate the variation of external ear dimensions, and (ii) determine the ear dimensions which discriminate between normal weight and underweight individuals of Hausa ethnic origin. The study was a cross sectional type involving 257 participants 136 normal weight and 121 underweight individuals. The mean age of the participant was 21.71 ± 2.52 years (18 – 30 years). Eight pairs of linear ear dimensions were measure using standard protocol. Independent sample t test was used for comparison of ear dimensions between the normal weight and underweight individuals. Receiver operating characteristic curve was employed to determine the best ear dimensions that discriminate between normal weight and underweight individuals. In both right and left ear dimensions, significant differences were observed only in ear length (EL), ear width (EW), ear lobe length and the distance between superior point of the auricle to intertragic notch (ITN). Tragus to helix showed significant difference only in the right ear. In all, normal weight individuals exhibited higher mean value compared to the underweight. The best discriminator was ear width in both right (AUC= 0.641, P < 0.001) and left ears (AUC= 0.668, P= P <0.001). This was followed by ITN (AUC= 0.624, P= 0.001) and EL (AUC= 0.642, P <0.001) for right and left ears respectively.
In conclusion, the ear dimensions varied between normal weight and underweight individuals of Hausa ethnic origin and the best discriminator was EW in both right and left ears.
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Discrimination between underweight and normal weight adults Nigerians of Hausa ethnic origin using right external ear dimensions
Discrimination between underweight and normal weight adults Nigerians of Hausa ethnic origin using left external ear dimensions
Variation in external ear dimensions between underweight and normal weight adults Nigerians of Hausa ethnic origin
Side
Ear Dimensions (mm)
Underweight (n=121)
Normal weight (n=136))
t
P value
Mean
SD
Mean
SD
Right
Ear length
54.13
3.87
55.93
4.35
−3.48
0.001
Ear width
31.50
2.57
32.71
2.20
−4.07
<0.001
Tragus‐helix
27.09
2.23
27.73
2.08
−2.39
0.018
Tragus‐antihelix
20.70
2.83
21.19
2.29
−1.53
0.127
Earlobe length
14.21
2.67
14.01
2.21
0.67
0.506
Earlobe width
16.13
5.21
17.81
4.69
−2.71
0.007
Superior point of the auricle to intertragic notch
41.41
5.92
43.86
4.65
−3.71
<0.001
Auricular projection
14.28
2.96
14.16
3.28
0.31
0.760
Left
Ear length
53.64
3.84
55.67
4.25
−4.01
<0.001
Ear width
31.10
2.67
32.68
2.41
−4.98
<0.001
Tragus‐helix
26.55
2.63
27.06
2.00
−1.75
0.082
Tragus‐antihelix
20.52
2.90
20.85
2.43
−0.97
0.333
Earlobe length
14.10
2.51
14.18
2.24
−0.27
0.784
Earlobe width
16.06
4.71
17.77
4.51
−2.97
0.003
Superior point of the auricle to intertragic notch
41.26
5.49
43.58
4.66
−3.66
<0.001
Auricular projection
13.78
3.17
14.06
3.51
−0.67
0.501
Area under the curve in variation in external ear dimensions between underweight and normal weight adults Nigerians of Hausa ethnic origin
Side
Ear Dimensions (mm)
Area Under the Curve
Std. Error
P value
Right
Earlength
0.62
0.03
0.0009
Ear width
0.64
0.03
0.0001
Tragus‐helix
0.57
0.04
0.0497
Tragus‐antihelix
0.55
0.04
0.1688
Earlobe length
0.49
0.04
0.7449
Earlobe width
0.59
0.04
0.0099
Superior point of the auricle to intertragic notch
0.62
0.03
0.0006
Auricular projection
0.48
0.04
0.5860
Left
Earlcngth
0.64
0.03
<0.001
Ear width
0.67
0.03
<0.001
Tragus‐helix
0.56
0.04
0.0977
Tragus‐antihelix
0.53
0.04
0.4095
Earlobe length
0.52
0.04
0.6737
Earlobe width
0.61
0.04
0.0035
Superior point of the auricle to intertragic notch
0.63
0.03
0.0005
Auricular projection
0.52
0.04
0.5865
This is from the Experimental Biology 2019 Meeting. There is no full text article associated with this published in The FASEB Journal.