caa a22 4500 397570384 CHVBK 20180308164839.0 cr unu---uuuuu 161202e199606 xx s 000 0 eng 10.1093/oxfordjournals.jmicro.a023435 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jmicro.a023435 Cartilage-Bone Replacement in Endochondral Ossification of Mandibular Condylar Heads in Young Beagle Dogs [Elektronische Daten] [Takahisa Sasaki, Tae-Weon Kim, Kazuhiro Debari, Haruyo Nagamine] The cellular mechanisms of cartilage-bone replacement in endochondral bone formation, in mandibular condylar heads, are poorly understood. In particular, there is no definitive evidence indicating whether cartilage is resorbed by so-called chondroclasts. Using 3-week-old male beagle dogs, we examined the cartilage-bone replacement processes in mandibular condylar heads by means of light and electron microscopy. Calcification of the cartilage matrix occurred in the central area of the longitudinal septa but not in thin transverse septa. Chondrocytic lacunae were opened by the removal of transverse septa by perivascular rough-surfaced endoplasmic reticulum (RER)-rich mononuclear cells. These cells also phagocytosed calcified cartilage fragments in the surface layer of longitudinal septa. Shortly thereafter, a thin bone layer was deposited on the remaining longitudinal septa by invading osteoblasts. Preosteoclastic multinucleated cells in lacunar canals developed neither ruffled borders nor clear zones in the cartilage matrix, but once the bone layer had been deposited on the remaining cartilage, these structures formed. Our results suggest that the cartilage-bone replacement in mandibular condylar heads involves four sequential processes: 1) degradation of the transverse septal cartilage by RER-rich mononuclear cells, 2) phagocytosis of calcified cartilage fragments in the longitudinal septa by these cells, 3) bone deposition on the remaining longitudinal septa, and 4) degradation of both bone and calcified cartilage by differentiated osteoclasts. © 1996 Oxford University Press Full-length Papers nationallicence mandibular condyles nationallicence growth plate nationallicence cartilage resorption nationallicence bone resorption nationallicence Sasaki Takahisa Department of Orthodontics, Ewha Womans University Mokdong Hospital, 911-1 Mok-Dong, Yangcheon-ku, Seoul, 158-056 Korea, 452-1 Toiso, Eniwa, 061-14 Japan, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142 Japan aut Kim Tae-Weon Department of Orthodontics, Ewha Womans University Mokdong Hospital 911-1 Mok-Dong, Yangcheon-ku, Seoul, 158-056 Korea aut Debari Kazuhiro Department of Orthodontics, Ewha Womans University Mokdong Hospital, 911-1 Mok-Dong, Yangcheon-ku, Seoul, 158-056 Korea, 452-1 Toiso, Eniwa, 061-14 Japan, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142 Japan aut Nagamine Haruyo Safety Research Department, New Drug Development Research Center, Inc. 452-1 Toiso, Eniwa, 061-14 Japan aut Microscopy Oxford University Press 45/3(1996-06), 213-222 0022-0744 45:3<213 1996 45 jmicro https://doi.org/10.1093/oxfordjournals.jmicro.a023435 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jmicro.a023435 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sasaki Takahisa Department of Orthodontics, Ewha Womans University Mokdong Hospital, 911-1 Mok-Dong, Yangcheon-ku, Seoul, 158-056 Korea, 452-1 Toiso, Eniwa, 061-14 Japan, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142 Japan aut NATIONALLICENCE 700 1- Kim Tae-Weon Department of Orthodontics, Ewha Womans University Mokdong Hospital 911-1 Mok-Dong, Yangcheon-ku, Seoul, 158-056 Korea aut NATIONALLICENCE 700 1- Debari Kazuhiro Department of Orthodontics, Ewha Womans University Mokdong Hospital, 911-1 Mok-Dong, Yangcheon-ku, Seoul, 158-056 Korea, 452-1 Toiso, Eniwa, 061-14 Japan, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142 Japan aut NATIONALLICENCE 700 1- Nagamine Haruyo Safety Research Department, New Drug Development Research Center, Inc. 452-1 Toiso, Eniwa, 061-14 Japan aut NATIONALLICENCE 773 0- Microscopy Oxford University Press 45/3(1996-06), 213-222 0022-0744 45:3<213 1996 45 jmicro Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford