There are numerous structural defects that occur in primate teeth due to variable calcification during certain growth stages. These interruptions are usually areas of hypomineralization in enamel and dentin which are referred to as Striae of Retzius and Hunter Shreger bands in the enamel or Incremental Lines of von Ebner and Contour Lines of Owen in the case of the dentin. The frequency of occurrence of these variations in mineralization can be related to such factors as growth tempo, dietary quality, state of health, and past disease episodes. Another structure that appears in the dentin is a region that fails to calcify and is referred to as Inter-globular Dentin.
Our studies have shown that the microstructural quality of different species' dentition varies widely. Samples obtained from certain free-ranging cercopithecoids show that these species have the least hypomineralizations while man has the most. Other primate species range between these two extremes with the pongids nearer to man in these characteristics, as previously noted by Sognnaes. Additionally, our initial study shows a great deal of diversity between prehistoric human populations in the microstructural quality of their teeth. We offer the tentative explanation that this variation is due to differences in the calcifying properties of the diet and hence a difference in the general state of their health.