The effect of increased oxygen tension on the growth of the mandibular condyle

Forty-eight Long Evans/Turku rats were exposed to increased oxygen tension at the age of 11 or 13 days. Three control and three experimental rats were killed after 3, 7, 11 and 14 days of exposure and 1, 5, 10, and 15 days after the animals had been returned to normal laboratory conditions. Glycosaminoglycan synthesis decreased when the oxygen tension increased, as indicated by reduced metachromasia of the cartilage. After the animals had been returned to normal laboratory conditions the glycosaminoglycan synthesis of chondroblasts and chondrocytes seemed to recover. Disturbances were seen in the intermediate cell layer of the condyle and later in the condylar cartilage. The results seem to indicate that there are differences in the metabolic state of the cells in different regions of the condyle. Variances in the metachromasia of the condylar cartilage appear to be affected by different oxygen tensions, which seem to be lowest in the superior region. The mesenchymal cells in particular seem to be sensitive to a drop in oxygen tension.