Immunohistochemical characteristics of developing mandibular angle in fetal mice

Mouse mandibular angle development started as a coagulation of mesemchymal cells on the 15(th) fetal day. On the 16(th )fetal day, cells of the central portion of the cell coagulation showed metachromasia to toluidine blue, and type 2 collagen positive chondrocytes were immunohistochemically detected. After the 17(th) fetal day, cartilaginous osteogenesis occurred with invasion of capillaries. At the same stage, membranous (perichondral) ossification occurred in the periphery of the chondrocyte mass. These proliferating chondrocytes showed positive reactions to type 2 collagen, type 1 collagen and osteopontin. These results suggest that the characteristics of mandibular angular cartilage are slightly different from those of normal physiological articular cartilage.