The Effect of Class II Elastic Forces on Craniofacial Growth in Rats

Abstract

Full-time Class II elastic forces were applied to eight rats in order to evaluate their effects on the growth of the snout and the mandible. Eight animals served as controls. Lateral cephalograms were taken at the start of the experiment and again at the end, 23 days later. The pre- and post-treatment tracings were superimposed on the cranial base to measure alterations in snout growth, and on metallic implants to measure differences in mandibular growth. As judged by t tests, Class II elastic forces caused a significant antero-posterior growth inhibition both in the snout and in the mandible.

Application of floating cells for improved harvest in human chondrocyte culture

“…Physiologically, chondrocytes proliferate and multiply even when surrounded by solid extracellular matrix in all directions. Thus, cartilage expands by means of interstitial growth in vivo (2,5). However, once chondrocytes are isolated from native tissue and begin to multiply in culture, they inevitably lose their ability to produce cartilaginous matrix components such as glycosaminoglycans (GAG) and type II collagen (COL2), and they begin to produce type I collagen (COL1) in a process termed dedifferentiation (3).…”