“…This transitional stage of root formation ends with the full development of the root when it reaches occlusal contact. 13 Lind 19 developed a radiographic method for measuring the relative length of the root, defined as the ratio between the length of the root and the length of the crown (R/C) (Fig 1). In a sample of 1,038 Swedish children, aged eleven or over, the normative value of R/C was 1.63 for males and 1.55 for females, without any statistical difference.…”