• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.70-76
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• 2011

Bone remodeling is a dynamic process involving a constant balance between osteoclast-induced bone resorption and osteoblast-induced bone formation. Osteoclasts play a crucial homeostatic role in skeletal modeling and remodeling, and destroy bone in many pathological conditions. Previously, we reported that the hexane soluble fraction of Ficus carica inhibited osteoclast differentiation. Poly unsaturated fatty acids, such as ethyl docosahexaenoate (E-DHA), docosahexaenoic acid (DHA), cis-11,14-eicosadienoic acid (EDA) and eicosapentaenoic acid (EPA), were identified from the hexane soluble fraction of Ficus carica. Among them, E-DHA most potently inhibited osteoclastogenesis in RAW264.7 cells. E-DHA reduced the activities of JNK and NF-$\kappa}B$. E-DHA suppressed the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1). Interestingly, DHA increased the activity of alkaline phosphatase and expression of bone morphogenetic protein 2 (BMP2) more than E-DHA in MC3T3-E1 cells, suggesting that DHA may induce osteoblast differentiation. The data suggests that a combination of E-DHA and DHA has potential use in the treatment of diseases involving abnormal bone lysis, such as osteoporosis, rheumatoid arthritis and periodontal bone erosion.

• The korean journal of orthodontics
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• v.42 no.4
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• pp.207-217
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• 2012

Objective: This study aimed to evaluate the effect of an intentionally created socket on bone remodeling with orthodontic tooth movement in rabbits. Methods: Eighteen male rabbits weighing 3.8 - 4.25 kg were used. An 8-mm deep and 2-mm wide socket was drilled in the bone 1 mm mesial to the right mandibular first premolar. The left first premolar was extracted to serve as an extraction socket. A traction force of 100 cN was applied to the right first premolar and left second premolar. Sections were obtained at the middle third of the moving tooth for both the drilled and extraction sockets and evaluated with hematoxylin and eosin staining and immunohistochemical analyses. The amount of tooth movement and tartrate-resistant acid phosphatase (TRAP)-positive cell count were compared between the 2 groups using the Mann-Whitney U test. Results: At week 2, the distance of tooth movement was significantly higher in the intentional socket group (p < 0.05) than in the extraction socket group. The number of TRAP-positive cells decreased in week 2 but increased in week 3 (p < 0.05). However, there were no significant differences between the groups. Furthermore, results of transforming growth factor (TGF)-${\beta}$ staining revealed no significant differences. Conclusions: The intentional socket group showed greater distance of tooth movement than did the extraction socket group at week 2. Osteoclast counts and results of immunohistochemical analyses suggested elevated bone remodeling in both the groups. Thus, osteotomy may be an effective modality for enhancing tooth movement in orthodontic treatment.

• Journal of Oral Medicine and Pain
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• v.46 no.3
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• pp.69-74
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• 2021

As for temporomandibular joint arthritis (TMJ OA), managing the contributing factors at an early stage through accurate diagnosis is necessary to prevent irreversible bone changes. TMJ OA, which is a multi-organ disease caused by various pathophysiological mechanisms, is developed mainly due to mechanical overload. It is a disease characterized by degeneration of articular cartilage and subchondral bone as a low-level inflammatory arthritis condition developed by dysregulation of catabolic and anabolic activity of chondrocytes. Age, mechanical overload sensing of cartilage, chondrocyte apoptosis, catabolic enzymes, inflammatory factors, abnormal remodeling of subchondral bone, and estrogens may be involved in the pathogenesis of arthritis. Therefore, a comprehensive evaluation is needed to diagnose and manage progressive cartilage degeneration, subchondral bone remodeling, and associated symptoms of TMJ OA.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.6
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• pp.354-359
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• 2023

The temporomandibular joint is a unique structure composed of the joint capsule, articular disc, mandibular condyles, glenoid fossa of the temporal bone, surrounding ligaments, and associated muscles. The condyle is one of the major components of a functional temporomandibular joint. Reconstruction of large mandibular defects involving the condyle is a surgical challenge for oral and maxillofacial surgeons. To restore large mandibular defects, there are different options for free flap method such as fibula, scapula, and iliac crest. Currently, the vascularized fibula free flap is the gold standard for reconstruction of complex mandibular defects involving the condyle. In the present report, neocondyle regeneration after mandible reconstruction including the condyle head with fibula free flap was evaluated. In this report, two patients were evaluated periodically, and remodeling of the distal end of the free fibula was observed in both cases after condylectomy or mandibulectomy. With preservation of the articular disc, trapezoidal shaping of the neocondyle, and elastic guidance of occlusion, neocondyle bone regeneration occured without ankylosis. Preservation of the articular disc and maintenance of proper occlusion are critical factors in regeneration of the neocondyle after mandible reconstruction.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.263-274
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• 1994

The purpose of this study was to investigate the remodeling process of the streptozotocin-induced diabetic rat's resected condyle. This experiment was performed with male Sprague-Dawly strain rats weighing approximately 250 gm, which were rendered diabetic by an intravenous injection of streptozotocin(70㎎/㎏ body weight). After condylectomy, experimental rats were serially terminated on the 1st week, the 2nd week, the 3rd week, and the 4th week. The following termination, the mandibles were dissected out to make specimens. Each mandibular condyle was radiographed with Hitex HA-80(Hitex Co., Ltd. Japan). In addition to radiographic observation, the mandibular condyles, further decalcified and embedded in paraffin, were sectioned and stained with Hematoxylin and Eosin, Toluidine blue and Masson's trichrome. They were observed with a light microscope and a polarizing microscope. The results were as follows. 1. Soft X-ray radiograms revealed proliferation of bone after 1 week in both groups. Irregularly repaired bones and dense trabeculae were clearly observed in experimental group. 2. The resected condyles were repaired by intramembraneous and endochondral bone formation in both groups. 3. Bone tissue repair was initiated from the adjacent margin of resected bone, and cartilaginous tissues were observed at the top of repaired bone in both groups. 4. The number of osteoblasts of experimental group was small, compared with control group. Each osteoblast was small and flat. The thin trabeculae were irregularly formed. 5. Collagens of bone were gradually matured in both groups, but the degree of maturation was lower in experimental group. 6. Fibrous tissues covered the upper parts of repaired bone were densely arranged in the both groups. Conclusively, atrophied osteoblasts, immature collagen of bone, and thin and irregular trabeculae which were characterized in the diabetes experimental group showed diabetes disturbed osteoblastic function and caused disturbance of remodeling process of bone.

• Journal of Korean Neurosurgical Society
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• v.54 no.6
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• pp.461-466
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• 2013

Objective : Although curcumin has a protective effect on bone remodeling, appropriate therapeutic concentrations of curcumin are not well known as therapeutic drugs for osteoporosis. The purpose of this study was to compare the bone sparing effect of treatment of low-dose and high-dose curcumin after ovariectomy in rats. Methods : Forty female Sprague-Dawley rats underwent either a sham operation (the sham group) or bilateral ovariectomy (OVX). The ovariectomized animals were randomly distributed among three groups; untreated OVX group, low-dose (10 mg/kg) curcumin administered group, and high-dose (50 mg/kg) curcumin group. At 4 and 8 weeks after surgery, serum biochemical markers of bone turnover were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae were determined by micro-computed tomography (CT). In addition, mechanical strength was determined by a three-point bending test. Results : High-dose curcumin group showed significantly lower osteocalcin, alkaline phosphatase, and the telopeptide fragment of type I collagen C-terminus concentration at 4 and 8 weeks compared with the untreated OVX group as well as low-dose curcumin group. In the analyses of micro-CT scans of 4th lumbar vertebrae, the high-dose curcumin treated group showed a significant increase in bone mineral densities (p=0.028) and cortical bone mineral densities (p=0.036) compared with the low-dose curcumin treated group. Only high-dose curcumin treated group had a significant increase of mechanical strength compared with the untreated OVX group (p=0.015). Conclusion : The present study results demonstrat that a high-dose curcumin has therapeutic advantages over a low-dose curcumin of an antiresorptive effect on bone remodeling and improving bone mechanical strength.

• The korean journal of orthodontics
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• v.50 no.1
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• pp.42-51
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• 2020

Objective: The objective of this study was to evaluate the effects of cetirizine, a histamine 1 receptor antagonist, on bone remodeling after calvarial suture expansion. Methods: Sixty male Sprague-Dawley rats were divided into 4 groups; the phosphate-buffered saline (PBS)-injected no expansion group, cetirizine-injected no expansion group, PBS-injected expansion group, and cetirizine-injected expansion group, and were observed at 7, 14, and 28 days. Five rats per group were examined at each observation day. Daily injections of cetirizine or PBS were administered to the relevant groups starting 2 weeks prior to expander insertion. A rapid expander was inserted in the calvarial bone to deliver 100 cN of force to the parietal suture. The specimens were prepared for hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) staining. Suture opening and bone regeneration were evaluated using microcomputed tomography and bone histomorphometric analysis. Serum blood levels of osteocalcin and carboxy-terminal collagen crosslinks (CTX) were also evaluated. Results: TRAP-positive cell counts and CTX levels decreased while osteocalcin levels increased in the cetirizine-injected expansion group at observation day 28. In the expansion groups, the mineralized area gradually increased throughout the observation period. At day 28, the cetirizine-injected expansion group showed greater bone volume density, greater mineralized area, and narrower average suture width than did the PBS-injected expansion group. Conclusions: Cetirizine injection facilitated bone formation after suture expansion, mostly by suppressing osteoclastic activity. Histamine 1 receptor antagonists may aid in bone formation after calvarial suture expansion in the rat model.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.871-883
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• 1994

This experiment was designed to study possible roles of $interleukin-1\beta$, interleukin-6 and tumor necrosis $factor-\alpha$ in bone remodeling by measuring their effects on $PGE_2,\; LTB_4$ and collagenase production when they were administered to human periodontal ligament fibroblasts. Human periodontal ligament fibroblasts were collected from first premolars extracted for orthodontic treatment. They were incubated in the environment of $37^{\circ}C,\;5\%\;Co^2,\;and\;100\%$ humidity. They were treated with $0.25\%$ trypsin-EDTA solution and centrifuged. PDL cells in the fifth to seventh passage were used for the experiment. Cells were seeded onto the culture dishes and when they were successfully attached, human recombinant $interleukin-1\beta$, interleukin-6, and tumor necrosis $factor-\alpha$ were administered, alone or in combination. They were incubated for 4, 8 and 24 hours and the levels of $PGE_2,\;LTB_4$ and collagenase released into the culture media were assessed by enzymeimmunoassay and collagenase activity assay. The conclusions are as follows: 1. $IL-1\beta\;and\;TNF-\alpha$ were very active in stimulating the production of $PGE_2$ and collagenase by human periodontal ligament fibroblasts, while IL-6 increased $LTB_4$ production. 2. $IL-1\beta$ significantly increased $PGE_2$, but $LTB_4$ Production was not increased. $IL-1\beta$ is thought to act mainly via the cyclooxygenase pathway of arachidonic acid metabolism. 3. IL-6 tended to inhibit $IL-1\beta$ in the production of $PGE_2$ and collagense whereas IL-6 and $TNF-\alpha$ showed auditive effect in the level of $PGE_2$. The above cytokines increased the release of at least one of $PGE_2,\;LTB_4$ and collagenase. It suggests that cytokines are involved in bone remodeling process by stimulating PDL fibroblasts to produce various bone-resorptive agents. The roles of cytokines in bone remodeling as a whole would need further study.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.1
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• pp.104-107
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• 2021

The orientation of trabeculae and porosity determine the wave propagation in cancellous bone. Wave propagation, as well as charge density and piezoelectricity, stimulate bone remodeling. Also, Charged ions in the fluid affect wave propagation in cancellous bone. But the trabecular struts' piezoelectricity does not change the waveform of cancellous bone. However, the underlying mechanism is unknown yet why trabecula struts' piezoelectricity does not change wave propagation through cancellous bone. Thus, we derived the governing equation indicating that trabecular struts' piezoelectric properties show that those do not affect wave propagation in cancellous bone.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.573-584
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• 2003

Bone remodeling results from the combined process of bone resorption and new bone formation which is regulated in part by some of Dexamethasone related proliferation & mineralization of cultured bone cell and polypeptide growth factors such as platelet derived growth factor(PDGF), which has been known to be an important local regulator of bone cell activity and participate in normal bone remodeling. To evaluate the effects of Dex and PDGF on bony healing of calvarial defect in rats, 10 ng/ml PDGF were applied on P group and 10 ng/ml PDGF and $10^7$ M Dex were applied PD group. 4 rats in each group were sacrificed at 7, 14. 21 days after operation respectively, and the tissue blocks were prepared for light microscope with H-E for evaluation of overall healing, with TRAP(tartrate resistant acid phosphatase) for evaluation of osteoclastic activity and with immunohistochemical staining for macrophages. The results were as follows : 1. In all group, healing aspects were progressed from 7 days to 21 days in soft and bony tissue, but complete repair were not observed in bony defect 2. PDGF and control group were showed similar bony healing aspect , but bony healing in combination of PDGF-BB and Dex were observed slower aspect compared to PDGF and control group from early healing times. 3. There were no significant difference on activities of osteoclast and macrophages in bony healing between control and experimental group In conclusion, PDGF were not influenced on bony healing of defect and combination of PDGF-BB and Dex were showed slower healing through early healing times. it was considered that Dex compared to PDGF did influenced on early hone formation factors in healing period