We have developed a simple in vitro model whereby precise quantities of compressive force can be applied to cultured chondrocytes from craniofacial cartilage: mandibular condylar cartilage (MCC), nasal septal cartilage (NSC), and spheno-occipital synchondrosis (SOS). Using this model, we found that hydrostatic compressive force stimulated glycosaminoglycan (GAG) synthesis, a cartilage phenotype, in MCC and SOS chondrocytes and DNA synthesis in MCC, NSC, and SOS chondrocytes. These stimulations were dependent on force magnitude and duration, reaching maximal GAG synthesis at 27 hours and maximal DNA synthesis at 20 hours after application of force. The maximal increase of GAG synthesis induced by compressive force was about 60% at 100 gm/cm2 for 5 minutes in nonstimulated MCC chondrocytes and 40% at 50 gm/cm2 for 1 minute in nonstimulated SOS chondrocytes. The maximal increase in DNA synthesis, produced by a compressive force of 50 gm/cm2 for 1 minute, was 50% in NSC chondrocytes, 50% in SOS chondrocytes, and 30% in MCC chondrocytes. There was no stimulation of GAG synthesis in NSC chondrocytes. These observations suggest that extrinsic force regulates craniofacial growth by controlling the differentiation and proliferation of chondrocytes in the craniofacial skeleton and that the difference in their responses to compressive force may reflect differences in the characteristics of these cells and their physiologic function in vivo.
|Number of pages||8|
|Journal||American Journal of Orthodontics and Dentofacial Orthopedics|
|Publication status||Published - 1991 May|
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