Study On The Ear Morphology Of 865 Han Ethnic Chinese In Northwest Region Of China

BackgroundHuman ears are important body surface organs. The ear deformities affect not only the appearances of the patients but also the psychological state of both the patients and their families. The prevalence of congenital microtia in China is 5.18/10000 and there is a large number of patients with congenital microtia, as well as other ear deformities,among Han ethnic Chinese of northwest region of China who require surgical corrections.Clinically, the early reconstruction of the defective ear would benefit the mental health of patients.Therefore, the understanding of the developmental characteristics of ear will help the surgical design. Based on the previous reports, the appearance and size of human ear are in constant change from birth through aldulthood and are distinct among races and residents of varied geographical territories, China has a vast territory with different regional living environments and the appearances of facial organs vary. Currently, the characterization of auricle morphology of the residents in Northwest China is scarcely reported and needs to be performed to fulfill the requirement of surgical planning and the study of body surface organs.Objective1. To explore the feasibility of photography method in auricular measurement.2. To characterize the changes of physiognomic ear length, ear width, morphological ear breadth, earlobe length, lobe width and auriculocephalic angle with age in Han ethnic Chinese of Northwest region of China.Methods1. The application of photography and digital vernier caliper direct measurement method were compared on the auricles of 5 Han ethnic Chinese coming from Northwest region of China.2. The physiognomic ear length, ear width, morphological ear breadth, earlobe length,lobe width and auriculocephalic angle were measured by a digital vernier caliper and a goniometer respectively on the left ears of 865 volunteers of 2 to 45 years old who were Han ethnic Chinese living in Northwest region of China and signed the informed consents. All participants were in sitting position with their heads were positioned on the Frankfurt horizontal plane when the measurements were collected. The age, gender,ethnics of each participant were recorded. The participants were grouped according to the age and gender. The data were statistically analyzed.Results1. There were statistically significant difference in the auricular measurement data between the photography and direct measurement methods on the 5 volunteers(P<0.05).2. The physiognomic ear length, morphological ear breadth and earlobe length increased with age. The mean male physiognomic ear lengths in 4-5 and 12-14 year age groups reached 84% and 93% of that in 18-30 year male group, respectively. The female physiognomic ear lengths in 4-5 and 12-14 year age groups reached 86% and 100% of that in 18-30 year female group, respectively. In male groups, the ear width of 8-9 year age group reached 96% of that in 18-30 year group while in female groups, the 6-7 years old physiognomic ear length reached 99% of that of 18-30 year age group. No change in the value of auriculocephalic angle was found after 2 years old.Conclusion1. The ear has a complex three-dimensional structure making photography method unsuible for the measurement of multiple indicators of the ear. In contrast, the directmeasuring method is a precise measurement required by the study of auricle morphology.2. The physiognomic ear length, morphological ear breadth and earlobe length all increase rapidly during the early years then become stable during adulthood. The ear size differs between gender groups of the same age. The auriculocephalic angle becomes stable from the early year. In male, the physiognomic ear length and morphological ear breadth at the age of 14 are near that of the adults while those measurements of female ear at the age of 13 are close to that of adults. The male ear width at 8 years old is near to that of adults whereas the female ear width of 6 years old is near to that of adults. 6 to10 years old is the best age of congenital ear reconstruction.