The proportion of the face in younger adults using the thumb rule of Leonardo da Vinci.

The present study was conducted to examine whether the thumb rule of Leonardo da Vinci could be an objective method in the determination of the natural and artistic proportions of human face. In this study, a sample of 400 subjects (200 male and 200 female, 22-25 years old) was used. Measurements were made of the length of thumb, the length of ear, the approximate distances between the hair line and the glabella or eyebrows, between the glabella or eyebrows and the tip of the nose and the distance between the nose and the chin, and the distance between the ear and the lateral aspect of the eye. The results obtained in the males and females showed significant (p < 0.01) correlations between the length of thumb and the proportions of the face examined in the study. Additionally, the height of the face was found to be almost three times the length of the thumb. However, the measurements obtained from female subjects were on average smaller than those taken from males. The results obtained in this experiment could be of value in understanding of the evaluation of the face for the people working in plastic surgery or art.