Defective enamel histology of prehistoric teeth from Illinois.

Histological enamel defects have been used as indicators of childhood morbidity and nutritional inadequacy. However, the usefulness of these defects has been hampered by a lack of clear criteria for differentiating normal and defective enamel. This report demonstrates that the criteria of abnormal prism structure can accurately differentiate defective enamel (i.e., pathological bands) from normal enamel. In addition, pathological bands can be divided into three distinct subtypes: distorted structure bands, black spot pathological bands, and structureless pathological bands. It has been assumed that the patterning of pathological bands and enamel hypoplasia is the same for all populations. Comparisons between populations show that each population has its own unique pattern. It has also been assumed that striae of Retzius, pathological bands, and enamel hypoplasias represent three grades of severity of the same phenomenon. Correlations between these three features demonstrate instead that this patterning is possibly influenced by the morphology of the teeth.