Pattern of Mitotic Activity and Cell Densities in the Epithelium of Inflamed Gingivae of Children

¹ Howard University College of Dentistry, Washington, D.C.

This study investigated the frequency of occurrence of mitoses and cell densities in the inflamed gingival epithelium of 43 children, ages five to thirteen years, in groups according to age and sex. The following observations were made: (1) The average mitotic index for the entire group was 0.545 cells per 1,000 epithelium cells. The average mitotic index for boys was 0.514 cells, and the average for girls was 0.575 cells per 1,000. (2) The lowest mitotic frequencies were found in nine-year-old boys and girls, and the highest frequencies in eleven-year-old boys and girls. (3) The differences in the mitotic rates in boys and girls of the same age groups were not statistically significant. (4) The deep third of the spinous layer displayed the greatest mitotic activity, followed by the basal layer, middle, and outer thirds of the spinous layer in that order. (5) A change in the relationship of metaphase/prophase ratio (PI) was noticed in inflamed gingival tissues. (6) The computed cell densities varied from 26.30 to 73.23 in boys and from 21.53 to 72.00 in girls per cm.² of the surface area. (7) An inverse relation was found between the cell densities and the average mitotic indices when different specimens were classified as to their density range of under 40.00, 40.00-49.00, 50.00-59.99, 60.00-69.99, and 70.00 and over. The average mitotic index decreased with an increase in cell density. (8) The reciprocal densities showed an increase with an increase in the mitotic index.