[Quantitative histological study of adult condylar proliferation zone]

The thicknesses and cell numbers of 43 adult condylar proliferation zone were observed by serial section and multiarea measurement in order to investigate the relationships between them and age. The samples were divided into three groups by age (19-45, 46-59, 60-74). By way of statistical analysis, the cell numbers and thicknesses of different areas of the same age group, different age of the same area, and the relationship between thicknesses and age was analysed. The results show that the average proliferation zone thickness is different among different age groups, it becomes thinner with the increase of age, and the cell number is decreased. There is high significant difference among different age groups (P < 0.01). But there is no significant difference of the proliferation zone thickness between the group of 45-59 years old and the older group (60-74)(P > 0.05). There is diverse correlation between thicknesses and age increase.