The mandibular condyles of eight man (Oberg and Carlsson, 1979). Stutzmann (19761, tracgrowing male monkeys (Macaca fascicularis) were aria-ing the number of mitotically active cells in the proliflyzed by using a combination of radioautographic and erative layer of rat condyles, indicated that the rate of morphometric techniques. This was done with the aim cell replication increases immediately after weaning and reaches a peak by about 38 days of age. In a model more activities of the articular tissue covering as well as of son et al. (1978) the thickness of the superfithe subchondral zone of erosion. The animals received cial articular layer and the subjacent complex of 1 mCikg body weight 3H-proline 24 hr and 0.5 m c i k g proliferative and cartilaginous layers and found maxibody weight 3H-th~midine 3 hr prior to death. Their age mum thickness of the latter complex during the infant was estimated on the basis of skeletal maturation as and juvenile age periods, i.e., simultaneously with the recorded from radiographs of the hand and wrist. Condeciduous and the early mixed dentition. Carlson et al. sistently, 1) the proliferative activity in the intemedi- (1978) assumed that thickness and growth activities of ate layer, 2) the rates of cell turnover and growth of the various layers may be related to one another and, chondroblasts and chondrocytes, 3) the rates of extrafor that that growth is most rapid during infant and juvenile age. Direct evidence cellular matrix production in the intermediate and supporting these assumptions is completely lacking, chondral layers, as well as 4) the resorptive and 5) however. appositional activities in the zone of erosion were char-The aim of the present study, therefore, was to examacterized by an in-concert behavior. This behavior SUgine whether there are differences in the various growth gests a general synergistic control of the various cell activities of condylar articular tissues between animals dynamic and metabolic processes affecting the rate of of different ages, and, if so, whether such differences normal condylar growth.
behave synergistically and result in alterations of layer thickness.
Methods
Of examining the dynamics in the structure and growth analogous to man, i.e., &facaca mulatta monkeys, Carl-