Dental Development is a Complex Adaptive System affected by environmental stress

Objectives: The development of the dentition is a valuable paradigm for general development. It displays the characteristics of a Complex Adaptive System and is a permanent record of major influences during its development. Our aims are to investigate dental developmental outcomes in a group of Romano-Britons subjected to substantial environmental stress, to compare these findings with those of Modern Britons and to consider possible mechanisms for any differences.
Methods: The excavated material of Romano-Britons from Poundbury, U.K. contains 486 intact jaws, subsamples from which were used in the four aspects studied. Visual examinations were made for tooth number and enamel hypoplastic defects. For crown diameters manual measurements were made using dial callipers. Six standardised radiographs covered the dentition of each individual. From these radiographs, the number of teeth present was confirmed and the root number, size and shape was scored. The same criteria were used in Modern Britons.
Results: In comparison with Modern Britons, the Romano-Britons had the same types of dental developmental defects; the same sexual dimorphisms in tooth number, size and shape and prevalence of their variations; threefold greater prevalence of hypodontia and microdontia; smaller crown size, root size and root shape; and threefold greater prevalence of enamel hypoplasia.
Conclusions: The findings for Romano- Britons probably resulted from severe environmental stress from high lead ingestion, poor nutrition with vitamin and mineral deficiencies, and recurrent infections affecting the whole dental development. These environmental agents may have acted in a summative or even synergistic manner. In addition to direct effects on tooth molecular and cellular processes, they may have affected the immune and endocrine systems and produced epigenetic changes. These findings have relevance for modern populations suffering environmental stress and emphasise the value of studying the dentition as a Complex Adaptive System and a model for general development.