Dorsal moiré topographies of 165 boys and 156 girls, aged 13 and 14, were investigated. Moiré fringe patterns were classified into seven types, of which type IV, thin and symmetric back, was most frequent (29% in boys and 22% in girls), and types I and II thoracic, fleshy back, were observed in 15% of boys and 29% of girls. Settling four prominent points on the back, length, depth (number of fringes), angles between these points, and the most depressed point on the lumbar region were measured. Neither bilateral or sex differences were detected in length and depth measurements, whereas larger right side angles were observed as a general tendency. In both sexes, significant correlation was detected between measurements on points situated in the inner part of the back, while on points situated in the outer parts only angle and length correlation was significant.