An estimation of ameloblast generation time and of the ameloblast proliferative compartment of guinea pig teeth.
The generation time of inner enamel epithelial cells has been estimated by many investigators using rodent and lagomorph teeth but the results have varied. In the present study of guinea pig molars, the inner enamel epithelial cell generation time (Tc) and its fractions (Ts, Tg2, Tm and Tg1) were calculated. Previous investigators have attempted to determine the extent of the proliferative compartment of inner enamel epithelial cells using the position of mitotic figures as their guide, but results have been inconsistent. It appears that this has been due to the small percentage of mitotic figures among the cell population and the difficulty of visualising them. In the present study, a novel approach was used to determine the extent of the inner enamel epithelial cell proliferative compartment which was not based on the position of mitotic figures, but on the calculation of other generation time fractions. It was found that the proliferative compartment extended for approximately 47 cells occlusally from the synthetic compartment. The results also showed that there was no evidence of stem cells in the ameloblast columns and hence, ameloblasts depended on their cell supply from the stem cell compartment apical to the ameloblast columns.
Nataatmadja
M I
MI
School of Dental Science, Oral Medicine and Oral Surgery Section, University of Melbourne, Victoria, Australia.
Orams
H J
HJ
Reade
P C
PC
D000565:Ameloblasts / Q000502:physiology*; D000818:Animals; D002452:Cell Count; D002455:Cell Division; D006168:Guinea Pigs; D008938:Mitosis; D008963:Molar / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology; D013997:Time Factors