Evaluation of biological maturation by means of maturity criteria

Abstract

Maturation may be conceived of as a series of gradual transformations through time going on in the human body from conception to death as part of the life cycle of the organism. Maturity was used as the general concept of any specified stage, or level, during the process of maturation. The maturity level was assessed by examining the attainment of various maturity criteria relating to dental development, skeletal development and pubertal development. In a group of children the attainment was analyzed by probit analysis using a logarithmic time concept (logarithmic conceptional age). This was exemplified by the attainment of breast stages according to Tanner in the girls of the present study. When examined a child was rated as being within a certain stage of maturity. The least advanced and the most advanced maturity level consistent with the rating was established using the probit lines. The relative maturity level was expressed in SD-scores of the Gaussian fitted distributions of age at attainment of various maturity criteria in a reference group of children. This was a laborious approach when there were many series of maturity criteria, i.e., in the assessment of skeletal maturity. In such cases each stage was instead given a certain maturity score. The individual maturity level was calculated by averaging the maturity scores of the stages, which were then evaluated in SD-scores by comparing with the Gaussian fitted distribution of averaged maturity scores at that age. In both approaches the evaluation of individual maturity was made with a relative scale of measurement. Accordingly, the rate of maturation could only be assessed indirectly.