• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.373-378
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• 1993

Although osteochondroma is not rare in the axial skeleton and long bones, it is very rare in the jaw. It is a benign chondroma within which partial endochondral ossification occurs. There are two types, the central one and the peripheral one. Peripheral type is more common than central one in the jaw, but it is not frequent. Especially it is rare at the mandibular condyle. When it occurred at the mandibular condyle, it is generally located at the lateral portion of the condyle. In that case, facial asymmetry with occlusal change is the characteristic clinical feature. But it is similar to condylar hyperplasia so that misdiagnosis can sometimes occur. The differential point is as follows: Hyperplasia generally appears as a generalized enlargement of the condylar process with a normal cortical thickness, but osteochondroma usually appears as a focal growth or mass. We report a very rare case of peripheral osteochondroma at the mandibular condyle in a 27-year- old male patient who visited DKUDH with a chief complaint of the facial asymmetry.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.41 no.4
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• pp.155-162
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• 2017

Connective tissue growth factor (CTGF, CCN2) is one of the multi-functional secreted proteins which belong to CCN family of cysteine-rich growth factors. CTGF is known to have pivotal roles in embryonic endochondral ossification but its role in relevance to periodontitis is never been determined. To identify new molecular mediators associated with periodontitis-induced bone resorption, we have analyzed publicly available GEO database and found the markedly augmented CTGF mRNA expression in periodontitis gingival tissues. The existence of CTGF significantly enhanced mature osteoclasts survival which accompanied by reduction in TUNEL-positive nuclei and PARP cleavage. These results may provide another line of evidence the CTGF mediated prolonged osteoclast survival and subsequent increased bone resorption in the periodontitis patients.

• BMB Reports
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• v.56 no.9
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• pp.496-501
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• 2023

Elongation of most bones occur at the growth plate through endochondral ossification in postnatal mammals. The maturation of chondrocyte is a crucial factor in longitudinal bone growth, which is regulated by a complex network of paracrine and endocrine signaling pathways. Here, we show that a phytochemical sulfuretin can stimulate hypertrophic chondrocyte differentiation in vitro and in vivo. We found that sulfuretin stabilized nuclear factor (erythroid-derived 2)-like 2 (Nrf2), stimulated its transcriptional activity, and induced expression of its target genes. Sulfuretin treatment resulted in an increase in body length of zebrafish larvae and induced the expression of chondrocyte markers. Consistently, a clinically available Nrf2 activator, dimethyl fumarate (DMF), induced the expression of hypertrophic chondrocyte markers and increased the body length of zebrafish. Importantly, we found that chondrocyte gene expression in cell culture and skeletal growth in zebrafish stimulated by sulfuretin were significantly abrogated by Nrf2 depletion, suggesting that such stimulatory effects of sulfuretin were dependent on Nrf2, at least in part. Taken together, these data show that sulfuretin has a potential use as supporting ingredients for enhancing bone growth.

• Applied Microscopy
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• v.31 no.3
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• pp.287-305
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• 2001

To investigate a role of cartilage canals in osteogenesis and growth of the vertebrae, in human fetuses ranging from 50 mm to 260 mm crown rump length were studied by electron microscopy. The initial appearance of cartilage canals of the vertebral body was observed at 60 mm fetus. In 80 mm fetus, primary ossification center in the vertebral body was first noted. The vertebral body showed calcified chondrocytes surrounded by a tone of hypertrophied chondrocytes and deep canals which terminated in calcified matrix. Most hypertrophied chondrocytes in the centrum showed in various stage of degeneration in disorderly arrangement. At the blind end of deep canal, osteogenic cells, osteoblasts and chondroclasts were observed. Resorption of unmineralized cartilage septa was undertaken by perivascular cells within cartilage canals. The ruffled border of the chondroclast was restricted to resorption site of calcified cartilagenous matrix. The periosteal bone formation was followed by the appearance of primary center of the centrum at 120 mm fetus. The osteoblasts of the perichondrium started to lay down a thin membranous bony lamella on the outer surface of the osseous trabeculae of the centrum. The processes of bone formation in the vertebral bodies were found to possess morphological similarities to that occurring at secondary center of the epiphysis of a long bone. These results indicate that the connective tissue cells within the cartilage canals proliferate and differentiate into osteoblasts at the site of endochondral ossification of the vertebrae.

• BMB Reports
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• v.49 no.2
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• pp.122-127
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• 2016

Engineered bone tissue is thought to be the ideal alternative for bone grafts in the treatment of related bone diseases. BMP9 has been demonstrated as one of the most osteogenic factors, and enhancement of BMP9-induced osteogenesis will greatly accelerate the development of bone tissue engineering. Here, we investigated the effect of insulin-like growth factor 1 (IGF1) on BMP9-induced osteogenic differentiation, and unveiled a possible molecular mechanism underling this process. We found that IGF1 and BMP9 are both detectable in mesenchymal stem cells (MSCs). Exogenous expression of IGF1 potentiates BMP9-induced alkaline phosphatase (ALP), matrix mineralization, and ectopic bone formation. Similarly, IGF1 enhances BMP9-induced endochondral ossification. Mechanistically, we found that IGF1 increases BMP9-induced activation of BMP/Smad signaling in MSCs. Our findings demonstrate that IGF1 can enhance BMP9-induced osteogenic differentiation in MSCs, and that this effect may be mediated by the enhancement of the BMP/Smad signaling transduction triggered by BMP9.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.261-270
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• 2004

The purpose of this experiment was to examine the histological changes and the pattern of expression of type I, II collagen in the elongated area by distraction osteogenesis in the rabbit mandible. Sixteen rabbits weighing 2.5kg-3kg were used for this experiment. Experimental group was distracted at the rate of 0.7mm, twice/day for 7days, and control group was only osteotomized. After 5 days latency, osteotomic site is distracted for 7days. Consolidation period is 28days. The animal was sacrificed at the 3rd, 7th, 14th, 28th day after the operation. The distracted bone was examined by histological analysis and RT-PCR analysis. The results were summarized as follows: 1. Experimental group was observed that the gaps between the distracted bone edges were occupied by new bone. 2. Expression of Type I collagen were detected throughout the experiment in both groups and Expression of Type I collagen were markedly increased during distraction and consolidation period in experimental group than control group. 3. Expression of Type II collagen were detected throughout the experiment in both groups and expression of Type II collagen were maintained at high level during distraction and consolidation period in experimental group than control group. From these results, in contrast to type II collagen, type I collagen seemed to be more expressed by mechanical stimuli during distraction and consolidation period. The predominent mechanism of new bone formation in the distraction gap was intramembranous bone formation, but some of the regenerated bone was formed by endochondral ossification.

• Molecules and Cells
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• v.24 no.1
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• pp.139-147
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• 2007

Although transforming growth factors (TGFs) are implicated in the process of endochondral ossification, which is initiated by the differentiation of mesenchymal cells into chondrocytes, it is not clear how $TGF-{\beta}3$ regulates the chondrogenic differentiation of limb bud mesenchymal cells. Here, differential display polymerase chain reaction (DD-PCR) screening and RT-PCR analysis revealed that transcripts of A Disintegrin And Metalloprotease 10 (ADAM 10) decreased during the chondro-inhibitory action of $TGF-{\beta}3$ on cultured chick leg bud mesenchymal cells. Electroporation of ADAM 10 morpholino antisense oligonucleotides inhibited the ectodomain shedding of delta-1, and cell proliferation and subsequent precartilage condensation, in a manner similar to that caused by $TGF-{\beta}3$. The suppression of mesenchymal cell proliferation induced by $TGF-{\beta}3$ and ADAM 10 morpholino antisense oligonucleotides was reversed by activation of ADAM 10 with phorbol 12-myristate 13-acetate (PMA) or knockdown of Notch-1 with siRNA. Collectively, these data indicate that, in cultured chick leg bud mesenchyme cells, $TGF-{\beta}3$ downregulates ADAM 10 and inhibits cell proliferation and subsequent precartilage condensation by inhibiting the ectodomain shedding of delta-1, and that this results in the activation of Notch signaling.

• Journal of Acupuncture Research
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• v.23 no.2
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• pp.103-111
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• 2006

Objectives : Deer antler Water Extract(DAE), prepared from the pilose antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe (Nokyong), a traditional immuno-suppressive and immuno-activating Korean herbal-acupuncture, is thought to play an important role in human bone remodeling. Methods : To determine whether DAE can induce the differentiation of resting zone chondrocytes(RC) or not, confluent cell cultures were pretreated for 24, 36, 48, 72, and 120hrs with DAE. At the end of pretreatment, the media were replaced with new media containing $10^{-10}{\sim}10^{-8}M\;1,25-(OH)_2D_3$ and the cells incubated for an additional 24hrs. Results : This second treatment was chosen because prior studies had shown that only the more mature growth zone chondrocytes(GC) respond to this vitamin $D_3$ metabolite. The effect of DAE pretreatment on cell maturation was confirmed by measuring alkaline phosphatase (ALPase)-specific activity. Changes in matrix protein synthesis were examined by measuring collagen synthesis, as well as $^{35}SO_4$ incorporation into proteoglycans. When RC cells were pretreated for 120h with DAE, treatment with $1,25-(OH)_2D_3$ caused a dose-dependent increase in ALPase-specific activity and collagen synthesis, however, the proteoglycan production was not affected. RC cells pretreated with $1,25-(OH)_2D_3$ responded like RC cells that had not received any pretreatment. Conclusion : These results indicate that DAE directly regulates the maturation of RC chondrocytes into GC chondrocytes. Therefore it was indicated that DAE may play a significant role in regulating chondrocyte maturation during endochondral ossification.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.5
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• pp.145-152
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• 2018

A 57 years old female complained of severe pain on the right temporomandibular joint (TMJ) area. Her right condyle had been partly resected under surgical operation 13 years ago due to condyle hypertrophy, thereafter she felt dull pain on TMJ area and recently the lesion became severely swelled and painful leading to cancer phobia. The present radiological views showed slightly enlarged and sclerosed condyle with increased radiopacity, but its articular sliding function was almost disable during mouth opening. The patient's TMJ lesion was carefully managed with conservative physiotherapy and pain treatment. The microsection of condyle head obtained from the previous operation was re-evaluated histologically, and it was finally diagnosed as osteochondrosis dissecans (OCD), exhibiting hyperplastic proliferation of cartilage in condyle head and marked vascular dilatation in epiphyseal zone. This abnormal cartilage tissue was distinguishable from normal cartilage tissue found in the peripheral cartilaginous cap of the same microsection. The involved cartilage cap showed thick hypertrophic chondrocyte zone with horizontal and vertical clefts accompanying diffuse hyaline degeneration. The superficial fibrous zone of cartilage cap was thickened and frequently peeled off, while lower hypertrophic zone of cartilage cap was highly cellular and proliferative. Consequently, the endochondral ossification became aberrant and resulted pre-mature apoptosis of many hypertrophic chondrocytes, followed by diffuse and mild inflammatory reaction in the underlying marrow tissue. Therefore, it was suggested that this hypertrophic condyle lesion, OCD, be differentiated depending on radiological and histological features from ordinary condyle hyperplasia, osteochondroma, and osteoarthritis, and that the pathological confirmation of OCD may provide a reliable modality for dental and medical treatment of chronic and painful TMJ lesion.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.187-196
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• 1996

Underlying malocclusions and dentofacial deformities are often related to variations in the craniofacial development. Type I and type II collagens are considered the major collagens of bone and cartilage respectively. Monitoring the patterns of those protein expressions during development will Provide a basis for the understanding of normal and abnormal growths. This study was undertaken to investigate the morphogenetic changes and the expression patterns of type I and II collagen proteins involved in the developing mandible of human embryos and fetuses. 50 embryos and fetuses were studied with Hematoxylin and Eosin, Alcian, blue-PAS, Masson Trichrome, md Immunohistochemical stains. The results were as follows : 1. A 13.5 mm embryo showed the stomatodeum with dental lamina, maxillary and mandibular processes. Meckel's cartilage appeared in the mandibular arch of a 20.5 mm embryo. New bone formation was bilaterally initiated at the outer side of middle portion of Meckel's cartilage of 22-38 mm embryos. 2. Meckel'cartilage was resorbed at the 15th week fetus. The endochondral ossification was observed where there was direct replacement of cartilage by bone. Meckel'cartilage disappeared and membraneous ossification were observed at the 25th week. 3. Before the appearance of Meckel's cartilage, the expression of type I collagen was moderate at the odontogenic epithelium of maxillary & mandibular process, but mild for the expression of type II collagen. 4. During the appearance of Meckel's cartilage and new bone formation, the immunoactivity of type II collagen was more expressed than type I collagen at the Meckel's cartilage and new bone. 5. During intrarmembranous bone formation, the expression of type II collagen was rare in the bony trabeculae. There was a switch for the expression of collagens from type II to type I during the appearance of Meckel's cartilage.