cell kinetics of rat molar periodontal ligament ( pdl ) during orthodontically-induced osteogenesis revealed : 1 ) primary growth fraction of 59 % , 2 ) proliferating cells from throughout the pdl migrate toward the bone surface , 3 ) preosteoblasts , capable of forming osteoblasts without synthesizing dna , are present in the pdl , 4 ) osteoblasts are derived from local pdl cells , and 5 ) cell death is a characteristic feature of the osteogenic response .
C0007634
cells
C0007587
cell death