A Study of Cell Height and Nuclear Volume in the Enamel Organ during Amelogenesis in the Upper Incisor of the Rat

¹ Department of Anatomy of the Faculdade de Medicina da Universidade de São Paulo, Brasil

In the present study the upper incisors of 36 Wistar rats were investigated by karyometric and cytometric methods in the three layers of the enamel organ and by a variety of histochemical methods for the demonstration of the presence of ribonucleic basophilia, mucopolysaccharides, and alkaline phosphatase in the enamel organ and in different stages of the enamel matrix formation.

Examination of the material described in the present investigation shows that the inner enamel epithelium is responsible for the primary and young enamel formation and, most probably, it differentiates young enamel into transitional enamel as well as participates in the processes of mineralization of these two latter stages of the enamel matrix. Our results indicate also that the stellate reticulum and stratum intermedium are the most responsible for the differentiation of young enamel into transitional enamel and the promotion of enamel matrix calcification.