Morphometry of the normal human ear: A cross-sectional study from adolescence to mid-adulthood

The objective of this study was to supply information about: (1) normal gen der-based dimensions of ears (linear distances and ratios, area); (2) left- right symmetry; and (3) growth changes between adolescence and mid-adulthoo d. The three-dimensional co-ordinates of several soft-tissue landmarks on t he ears and face were obtained by an electromagnetic digitizer in 40 male a nd 33 female adolescents aged 12-15 years, 73 young female and 89 young mal e adults aged 19-30 years, and 41 male and 38 female adults aged 31-56 year s. From the landmarks ks, paired ear width and length were calculated and a veraged for age and gender, as well as the relevant ratios, ear areas and a ngles relative to the facial midline, and indices of left-right symmetry. C omparisons were performed by factorial analysis of variance. All ear dimens ions were significantly larger in men than in women (P < 0.005). A signific ant effect of age was found (P < 0.005), with larger values in older indivi duals. On average, the three-dimensional position of ears was symmetric, wi th symmetry coefficients ranging between 94 and 96%. Data collected in the present investigation could serve as a database for the quantitative descri ption of human ear morphology during normal adolescent and adult growth.