Abstract
Age changes of cells of the periodontal ligament adjacent to the cementum were observed by transmission electron microscope. Morphometric analysis was processed in the 20, m area of the periodontal ligament from the cemental surface. Forty human permanent teeth aged from 13 to 73 years were used in this study. The results were as follows.
1.Cells of the periodontal ligament adjacent to the cementum showed a densely cellular layer with functional differentiation.
2.Age changes on the cell density, nuclei and cytoplasms were not significant.
3.With respect to organelles, there was little age changes of the number in mitochondrias, but the size of cross-section increased in old age. No significant statistical differences were shown in the size of rough-surface dendoplasmic reticulums between in the young and the old.
