A Scanning Electron Microscope Study of Monkey Maturation-stage Ameloblasts

Abstract

The maturation-stage enamel organs of Macaca arctoides and Macaca mulatta were examined in order to determine whether the cells were similar to those of the continuously erupting rat incisor. Tooth buds of the permanent dentition were fixed in fonnaldehyde-glutaraidehyde and post-fixed in OsO₄. The enamel organs were separated from the enamel during dehydration, critical-point-dried, metal-coated, and examined in a scanning electron microscope.

The results showed that there were few differences in the morphology of maturation-stage ameloblasts of these primates compared with those of other species reported in the literature. The apical plasma membranes were either smooth- or ruffle-ended, while the later membranes had maze, microvillous, or ridge configurations, also seen in rats, and an additional configuration of interdigitating bulbous extensions. The blood vessels of the papillaiy layer in monkeys were about 7 μm in diameter, considerably larger than those of the rat.