Pelz L, Stein B
Abteilung Neonatologie und Klinische Genetik, Bereiches Medizin der Wilhelm-Pieck-Universität Rostock.
Padiatr Grenzgeb. 1990;29(3):229-35.
In 1271 children and adolescents of both sexes (596 boys and 675 girls) anthropometric measurements of the "physiognomic external ear length and ear width" were carried out by means of a caliper in order to make the clinical symptoms of macrotia and microtia, respectively, more objective than by clinical impression, only. In the mean ear lengths steadily and annually grow 0.66 mm in boys and 0.46 mm in girls, +/- 2s-border-lines based on a nonlinear regression model y = f(means +/- 2s) = a + b.ln x are calculated: For boys it is y + 2s = 47,9164 + 6,9539.ln x and y-2s = 36,7839 + 6,1172.ln x, respectively, for girls the regression equations are as follows: y + 2s = 49,1431 + 5,6002.ln x and y-2s = 41,3945 + 3,2266.ln x. The approximation of the regression model to the data observed is highly significant (alpha less than 0.0005). In contrast to the auricle length "physiognomic external ear width" is independent of age in both sexes, namely in boys means = 32.89 +/- 0.1176 mm and in girls means = 31.21 +/- 0.0876 mm. All sex differences are highly significant (alpha less than 0.0005).