About chondroid tissue

Nearly impossible to evidence with classical paraffin sections, chondroid t issue is regularly absent in the chapters of texbooks dealing,vith skeletal growth in which however it represents one of the major constituents. Micro radiograph and methylene blue surface staining of thick undecalcified secti ons are the most suitable methods to reveal the presence of chondroid tissu e. Moreover, all the methods used clearly indicate that this tissue is diff erent from both calcified cartilage and woven bone oi lamellar bone. The si multaneous presence, within the chondroid tissue matrix, of collagen type I , specific for bone tissue, and type II, specific for cartilage enables als o to distinguish chondroid tissue from all the other calcified tissues. The presence of chondroid tissue in both fetal mandibular symphysis and in the sutural spaces of the skull strongly suggests that the same biomechanical stresses have the same consequences, i.e. the growth of the tongue separate s the hemimandibles and the development of the brain has the same effect on the sutural areas Experimental production of chondroid tissue is obtained in the space appeared between the bone fragments submit ted to a continuous distraction. Finally, since the first cranial vault is also constituted by chondroid tissue islets, it has to be concluded that bone tissue if always secondary in its origin, i.e.. after hyaline cartilage in endochondral oss ification find after chondroid tissue in membranous ossification.