[Biodevelopmental and biostatistical aspects of the concept of normal values in the 1st and 2d dentition].

In conformity with the practice in other biological sciences, it is suggested to adopt in dentition chronology the double of the range around the mean as the range of normal. The great variance especially in the second dentition agrees with the variance of other developmental characteristics and must be considered to be typical of human development. The integration of dentition with the complex of the characteristics of physical and psychical development is advocated.