The ameloblast movement in rat incisor. L.M., S.E.M. and C.L.S.M. study

The internal epithelium of enamel organ and the below enamel surface during growth of the lower incisor, were examinated in ten Wistar rat 12-27 weeks old and weighing between 150/200 gr, by means of immuno histochemical, light and scanning electron microscopy techniques. Our specimens indicate that during the outer enamel secretion the anti-actin positivity goes from distal terminal web to infra nuclear region of cell body. The results of the present study do not support the active movement hypothesis, conversely they support the Warshawsky (1992) hypothesis, i.e. the distal terminal web permits the maintenance and the assembling of ameloblasts during enamel growth. Hence we do agree with Osborn (1970) who reported that, during secretion, ameloblasts move passively in response to secretory forces.