Progression of growth in the external ear from birth to maturity: a 2-year follow-up study in India

This study aimed to follow the growth dynamics of auricular dimensions from birth to the age of 18 years. The norms of dimensions at different ages, the peak growth period and the maturity age of the dimensions are essential information to Physicians for early clinical diagnosis or for deciding the optimal time for surgery to correct abnormalities.

For this study, 2,147 children belonging to central Indian population were measured in at least three sequential sessions. Eight dimensions including the physiognomic length and width of the ear and its morphologic width; conchal length, width, and depth; and lobular length and width were measured using anthropometric technique. Three new dimensions (tragal length and height and maximum width of the antihelix) were introduced in the study. Three indices (auricular, conchal, and lobular) also were derived.

Most dimensions exhibited very rapid growth during the first 3-6 months of infancy and thereafter proceeded at a slow pace until adulthood. The smaller dimensions (conchal depth, tragal height, and maximum width of the antihelix) increased continuously throughout the growth period. At birth, most of the dimensions were 52-76 % of their adult size, while tragal length and height were less than half their adult size. Unlike the other dimensions, the lobule length was smaller in males, probably due to the higher frequency of hypoplastic and bow-shaped lobules among them. The width dimensions matured earlier, at 5.6-11 years, whereas the maturity age of lengths varied from 12 to 16 years.

The data generated in the current study will be useful to Physicians as a guideline in correcting auricular deformity and in constructing age progression charts of the external ear. Knowledge concerning the maturation age of the ear will help law enforcement authorities in deciding when to use it for establishing personal identification.

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