Cellular dynamics in root formation of teeth in rhesus monkeys.

The role of the various cellular components associated with root formation has been controversial since Malassez' and Hertwig2 presented their theories. The advent of isotopes such as tritiated thymidine has made it possible to study cellular turnover and migratory patterns with much greater accuracy than was previously possible. Such technics have been applied to studies of mitotic activity associated with tooth formation, frequently for continuously erupting teeth in small animals.3-9 However, the migration pattern of the cells involved in root formation has received little attention. The purpose of the present study was to investigate the pattern of cell movements associated with root formation in order to gain a better understanding of the role of the various cellular elements in the formation of cementum and dentin at the apex of the growing root.