[Study of scalp hair patterns in the newborn infant].

A study of scalp hair patterns in 503 healthy patterns in 503 healthy neonates (260 boys and 243 girls) of more than 36 weeks gestation produced the following observations: 1.--A single whorl situated to the right of the midline in a clockwise rotation is the most frequent pattern. 2.--In 5.96% of cases there is a pattern not previously identified which we have called triradius and which is characterised by the arrangement of three locks of hair without a clear clockwise rotation. 3.--75.4% of the patterns, whatever their type, are located 2 to 4 cms from the posterior fontanelle. 4.--The percentage of whorls, double whorls, triradii and their position (right, left of midline) are significantly different according to sex. 5.--By contrast there is no significant racial difference in these parameters.