• International Journal of Oral Biology
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• v.39 no.3
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• pp.145-151
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• 2014

During bone remodeling, there is requirement of differentiation of osteoblastic cells. Previously, we identified proteins differentially expressed in soft tissue during bone healing. Of these proteins, we focused the effect of LTF on differentiation of osteoblast. In order to analyze the osteogenic ability of LTF, we treated conditioned media collected from human LTF-stably transfected HEK293T cells into osteoblastic MC3T3-E1. The results showed that the activity and expression of alkaline phosphatase were increased in MC3T3-E1 cells treated with conditioned media containing LTF in dose- and time-dependent manner. At the same time, we observed the significant increase of the expression of osteoblastic genes, such as ALP, BSP, COL1A1, and OCN, and along with matrix mineralization genes, such as DMP1 and DMP2, in LTF conditioned media-treated groups. Moreover, the result of treating recombinant human LTF directly into osteoblastic MC3T3-E1 showed the same pattern of treating conditioned media containing LTF. Our study demonstrated that LTF constitutively enhances osteoblastic differentiation via induction of osteoblastic genes and activation of matrix mineralization in MC3T3-E1 cells.

• The Journal of the Korean bone and joint tumor society
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• v.6 no.2
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• pp.106-111
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• 2000

Focal fibrocartilaginous dysplasia(FFCD) is an uncommon, benign condition associated with unilateral tibia vara among young children. FFCD has a typical plain radiographic finding, which has a concave radiolucent defect in the metadiaphyseal junction of medial aspect of the proximal tibia. The varus deformity occurs at the site of the lesion. Spontaneous remodeling and resolution of bony defect may be expected, but the corrective osteotomy may also be needed in some cases. The authors described a case of unilateral tibia vara caused by FFCD, diagnosed by excisional biopsy and treated with dome-shaped proximal tibial osteotomy and bone graft.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.3
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• pp.169-176
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• 2010

The hyperosmotic stimulus is regarded as a mechanical factor for bone remodeling. However, whether the hyperosmotic stimulus affects $1{\alpha}$, 25-dihydroxyvitamin $D_3$ ($1{\alpha},25(OH)_2D_3$)-induced osteoclastogenesis is not clear. In the present study, the effect of the hyperosmotic stimulus on $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis was investigated in an osteoblast-preosteoclast co-culture system. Serial doses of sucrose were applied as a mechanical force. These hyperosmotic stimuli significantly evoked a reduced number of $1{\alpha},25(OH)_2D_3$-induced tartrate-resistant acid phosphatase-positive multinucleated cells and $1{\alpha},25(OH)_2D_3$-induced bone-resorbing pit area in a co-culture system. In osteoblastic cells, receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) and Runx2 expressions were down-regulated in response to $1{\alpha},25(OH)_2D_3$. Knockdown of Runx2 inhibited $1{\alpha},25(OH)_2D_3$-induced RANKL expression in osteoblastic cells. Finally, the hyperosmotic stimulus induced the overexpression of TonEBP in osteoblastic cells. These results suggest that hyperosmolarity leads to the down-regulation of $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis, suppressing Runx2 and RANKL expression due to the TonEBP overexpression in osteoblastic cells.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.493-509
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• 1998

Osteoarthritis(degenerative joint disease), the most common arthropathy affecting the aged people, is characterized by degeneration of articular cartilage with proliferation and remodeling of subchondral bone. Osteoarthritis of the knee, which probably has greater social cost and more associated disability than osteoarthritis of any other joint, prevalence is known to increase with age, and females have higher rates than males; radiographic abnormalities are present in more than 30% of persons more than 65 years old, with approximately 40% of these persons symptomatic. Though the etiology of osteoarthritis is not entirely understood, much information is available regarding risk factors for the development of knee osteoarthritis that permit some reasonable guideline for preventive strategies. Traumatic damage or occupational or recreational overuse of knee joint may result in osteoarthritis, and obesity also is related to osteoarthritis of the knee. A variety of other possible risk factors for the development of knee osteoarthritis have been proposed, including increased bone mass, smoking, diseases such as diabetes or elevated serum uric acid, and some metabolic factors, but the contribustions of these and other factors such as smoking or race and diseases such as diabetes are as yet undetermined. The usual clinical manifestations include pain, stiffnesss, crepitus and loss of function. In oriental medicine, osteoarthritis of the knee is very similar to diseases such as Bijung(痺症), Haksulpung(鶴膝風), Youkjeolpung(歷節風) in symptoms. The diseases such as Bijung(痺症), Haksuipung(鶴膝風), Youkjeolpung(歷節風) is related to the of function liver(肝) and kidney(腎) and risk factors are regarded as Pung(風), Han(寒), sub(濕). The diagnosis of osteoarthritis of the knee has often been based on radiographic appearance and clinical manifestations. The acupuncture therapy of osteoarthritis of the knee has often been based on Stomach meridian(ST), Spleen meridian(SP), Kidney meridian(KI), Liver meridian(LR).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.3
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• pp.139-144
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• 2012

This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from $34.5{\pm}2.1$ mm to $37.2{\pm}3.5$ mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. Conclusion: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).

• Biomolecules & Therapeutics
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• v.21 no.3
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• pp.204-209
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• 2013

Osteoprotegerin (OPG) is a secreted glycoprotein and a member of the tumor necrosis factor receptor superfamily. It usually functions in bone remodeling, by inhibiting osteoclastogenesis through interaction with a receptor activator of the nuclear factor ${\kappa}B$ (RANKL). Transglutaminases-2 (Tgase-2) is a group of multifunctional enzymes that plays a role in cancer cell metastasis and bone formation. However, relationship between OPG and Tgase-2 is not studied. Therefore, we investigated the involvement of 12-O-Tetradecanoylphorbol 13-acetate in the expression of OPG in MG-63 osteosarcoma cells. Interleukin-$1{\beta}$ time-dependently induced OPG and Tgase-2 expression in cell lysates and media of the MG-63 cells by a Western blot. Additional 110 kda band was found in the media of MG-63 cells. 12-O-Tetradecanoylphorbol 13-acetate also induced OPG and Tgase-2 expression. However, an 110 kda band was not found in TPA-treated media of MG-63 cells. Cystamine, a Tgase-2 inhibitor, dose-dependently suppressed the expression of OPG in MG-63 cells. Gene silencing of Tgase-2 also significantly suppressed the expression of OPG in MG-63 cells. Next, we examined whether a band of 110 kda of OPG contains an isopeptide bond, an indication of Tgase-2 action, by monoclonal antibody specific for the isopeptide bond. However, we could not find the isopeptide bond at 110 kda but 77 kda, which is believed to be the band position of Tgase-2. This suggested that 110 kda is not the direct product of Tgase-2's action. All together, OPG and Tgase-2 is induced by IL-$1{\beta}$ or TPA in MG-63 cells and Tgase-2 is involved in OPG expression in MG-63 cells.

• The korean journal of orthodontics
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• v.20 no.3 s.32
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• pp.499-517
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• 1990

Electrical stimulation among several factors that influence bone remodeling has been studied by many investigators with great enthusiasm in orthodontic field. The action mechanisms of Pulsed Electromagnetic Field (PEMF) are different from those of the conventional electrode application method in that PEMF induces endogenous current in the living tissues. PEMF is known to have the healing effect in nonunion of bone and osteoporosis. It is widely used in orthopaedic scopes and the possibility of using the method in clinical orthodontics Is also conceivable. But the exact mechanisms by which the PEMF exerts its effects are not clearly understood. Therefore, the author wanted to see the effect of PEMF on five groups of rat calvarial cells obtained by sequential enzyme digestion method, and observed the changes in enzyme activation, collagen synthesis and $^3H-thymidine$ incorporation. The results were as follows: 1. Under the effect of PEMF, there were no changes in the alkaline phosphatase activity in five groups of cell populations. 2. Both the PEMF group and the PTH with PEMF group shelved no changes in acid phosphatase activities and there were no differences between two experimental groups. 3. Under the effect of PEMF, there was significant increase of collagen synthesis in the group V cell population. 4. Under the effect of PEMF, there were significant increases of $^3H-thymidine$ incorporation in the group IV and V cell populations.

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.455-466
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• 2002

The objective of this study was to evaluate the changes that occurred over time in the distracted periodontal ligament space following the rapid retraction of a tooth by periodontal distraction after bone undermining surgery had been conducted in the dogs. The upper second premolars were extracted on the left and right side in 4 male beagle dogs. Immediately after extraction, the interseptal bone distal to the upper first premolar was thinned and undermined by grooving to decrease the bone resistance. Activating an individualized distraction appliance at the rate of 0.225mm twice a day, the upper first premolar was retracted rapidly toward the extraction socket. Periodontal distractions were performed for 5, 10, and 20 days, and 20-day-distraction cases were followed by maintenance periods of 0, 14, 28, and 56 days. After 20 days of rapid retraction, the average distal movement of the upper first premolar was 5.02mm, and the average mesial movement of the upper third premolars serving as an anchorage unit was 0.18 mm. On histological examination, the regeneration of bone occurred in a highly organized pattern. Distracted periodontal ligament space was filled with newly formed bone oriented in the direction of the distraction, and this was followed by extensive bone remodeling. This result was similar to those observed in other bones after distraction osteogenesis. In the periodontal ligament, the relationship between collagen fibers and cementum began to be restored 2 weeks after the distraction was completed, and showed almost normal features 8weeks after the completion of the periodontal distraction. However, on the alveolar side, the new bone formation was still in process and collagen fiber bundles and Sharpey's fibers were not present 8 weeks after the completion of the periodontal distraction. Reactions in the periodontal ligament of the anchorage tooth represented bone resorption on the compressed side and new bone deposition on the tension side as occurred in conventional orthodontic tooth movement. In conclusion, the results of this study showed that periodontal structures on the distracted side of the periodontal ligament were regenerated well histologically following rapid tooth movement.

• The korean journal of orthodontics
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• v.38 no.6
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• pp.416-426
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• 2008

The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. Methods: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150-200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using $Periotest^{(R)}$. Results: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. Conclusions: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage.

• The korean journal of orthodontics
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• v.31 no.3 s.86
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• pp.369-379
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• 2001

The aim of this study was to investigate the periodontal response according to the timing of orthodontic force application after bone graft into the angular bony defect. Nine dogs were divided into three groups, 2, 4, and 6 weeks, according to the timing of orthodontic force application after bone graft. Periodontal angular bony defects were created surgically at the distal aspect of both maxillary third incisors. Two weeks later, flap operation was performed to eliminate inflammation and reference notch was made on the root surface at the level of the bottom of each defect. Demineralized freeze-dried bone was implanted on the left side whereas only debridement was done on the other side. Experimental tooth movement was executed during 8 weeks on both graft and non-graft sides. After 2 weeks of retention period, animals were sacrificed for histologic specimens. The results were obtained as follows 1 New bone formation was more pronounced in the graft side than in the non-grad side in all experimental animals. 2. In the 6-week group, new bone and cementum formation was observed in more than half from the notch to the cemento-enamel junction, and the zone of connective tissue attachment was found without apical migration of junctional epithelium. 3. In the 4-week group, the amount of new bone formation was smaller than in the 6-week group whereas the overall remodeling pattern was similar. 4. New bone formation was confined to around the notch and the junctional epithelium migrated apically to the level of the notch with no connective tissue attachment and cementum formation in the 2-week group. The results of the present study suggest that periodontal response may be influenced by the timing of orthodontic force application after bone graft into angular bony defect.