The aim of this study was to develop a measurement scale to quantify facial aesthetics. Four series of 36 standardized facial photographs (boys 11-13 years; girls 11-13 years; boys 14-16 years; girls 14-16 years) were judged twice by eight orthodontists, eight laymen, and eight children. This was undertaken by comparing each photograph with one reference photograph of a child of the same sex and age. Pearson's correlation coefficients were calculated to determine intra-observer agreement (median Pearson's correlation r = 0.78), and to assess the correlation between the scores of each judge and those of the others in that panel (median Pearson's correlation r = 0.71). Alpha coefficients were calculated as a measure for the reliability of the composed scores (median alpha coefficient alpha = 0.90). Finally, the correlation between the three jury panels was established (median Pearson's correlation r = 0.84). The results showed that the reproducibility of rating facial aesthetics is good. Moreover, a high level of agreement was found between the ratings of different panels. Therefore, a mean overall score for each judged photograph could be calculated. Finally, for each age and sex group a metric scale was composed, consisting of five photographs with their scores. These scales can be used to evaluate the results of orthodontic treatment with respect to facial aesthetics.