• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.6
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• pp.535-539
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• 2011

Epidermoid cyst is a cystic form of teratoma and believed to be derived from trapped embryonic cells along the lines of embryonic closure. A 28-year-old woman presented with a painless swelling over the left mandibular area. On panoramic view, the mandible revealed a $5.5{\times}2.0\;cm^2$ multilocular radiolucent lesion of the left mandibular body and a computed tomography scan showed expansion of both the buccal and lingual plates in the same area. Microscopy found stratified squamous epithelium of the cystic wall and cystic contents of keratinized material. The histological diagnosis wasan epidermoid cyst. The most common location of epidermoid cyst at the head and neck is in the orbit (47%), followed by the mouth floor (23%) and the cervical area (9~24%), but in the jaw bone, it is considered very infrequent. We report the uncommon epidermoid cyst in the mandibular body that had a good healing outcome after treatment with a conservative marsupialization during the 40 months follow-up.

• Imaging Science in Dentistry
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• v.44 no.4
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• pp.321-324
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• 2014

Postoperative maxillary cysts are locally aggressive lesions, usually developing as delayed complications many years after radical antral surgery. This report describes a case of bilateral postoperative maxillary cysts following orthognathic surgery performed approximately 21 years previously. The patient complained of stinging pain on her right cheek. Radiographic examination revealed low-attenuation lesions on both maxillary sinuses with discontinuously corticated margins without distinct expansion or bone destruction. The cysts were enucleated with the removal of metal plates and screws for pain relief. Histopathological examination confirmed the diagnosis of postoperative maxillary cysts lined by ciliated, pseudostratified columnar cells. The patient has remained asymptomatic thus far, and there was no evidence of local recurrence at 21 months of postoperative follow-up.

• Steel and Composite Structures
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• v.42 no.6
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• pp.765-777
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• 2022

Ultra high performance concrete (UHPC) can be used in the UHPC-steel composite structures especially for bridge structures to achieve high stiffness and high fatigue resistance with low self-weight. The structural performances of UHPC-steel composite slabs subjected to hogging moment have a significant influence on the global stiffness and durability of UHPC-steel composite structures. In order to study the structural behaviors of non-steam-cured UHPC-steel composite slabs subjected to negative moment, five composite slabs combined the thin UHPC layers to steel plates via shear stud connecters with the diameter of 16mm were fabricated and tested under negative moment. The test program aimed to investigate the effect of stud spacing and longitudinal reinforcement ratios on the failure mode, load-deflection behaviors, cracking patterns, bond-slips, and carrying capacities of composite slabs subjected to negative moment. In addition, direct tensile tests for the dog-bone UHPC specimens with longitudinal reinforcement bars were carried out to study the effect of reinforcement bars on the tensile strength of UHPC in the thin structure members. Based on the experimental results, analytical models were also developed to predict the cracking load and ultimate load of UHPC-steel composite slabs subjected to negative moment.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.52.1-52.11
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• 2020

Objectives: Yttria-stabilized tetragonal phase zirconia has been used as a dental restorative material for over a decade. While it is still the strongest and toughest ceramic, its translucency remains as a significant drawback. To overcome this, stabilizing the translucency zirconia to a significant cubic crystalline phase by increasing the yttria content to more than 8 mol% (8YTZP). However, the biocompatibility of a high amount of yttria is still an important topic that needs to be investigated. Materials and Methods: Commercially available 8YTZP plates were used. To enhance cell adhesion, proliferation, and differentiation, the surface of the 8YTZP is sequentially polished with a SiC-coated abrasive paper and surface coating with type I collagen. Fibroblast-like cells L929 used for cell adherence and cell proliferation analysis, and mouse bone marrow-derived mesenchymal stem cells (BMSC) used for cell differentiation analysis. Results: The results revealed that all samples, regardless of the surface treatment, are hydrophilic and showed a strong affinity for water. Even the cell culture results indicate that simple surface polishing and coating can affect cellular behavior by enhancing cell adhesion and proliferation. Both L929 cells and BMSC were nicely adhered to and proliferated in all conditions. Conclusions: The results demonstrate the biocompatibility of the cubic phase zirconia with 8 mol% yttria and suggest that yttria with a higher zirconia content are not toxic to the cells, support a strong adhesion of cells on their surfaces, and promote cell proliferation and differentiation. All these confirm its potential use in tissue engineering.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.523-526
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• 2014

Three dogs were admitted for repair of bone fracture. Case 1 (Maltese, 1.8 kg, intact female, 5-month-old) and case 2 (poodle, 3.0 kg, intact female, 6-month-old) had non-weight bearing lameness in the left pelvic limb, and case 3 (mixed, 3.3 kg, intact female, age unknown) had non-weight-bearing lameness in the left thoracic limb. On orthopedic examination, there was pain, crepitus, palpable instability and substantial soft tissue swelling on the affected side. No neurological deficits were identified. Radiographs revealed left proximal metaphyseal tibial and fibular fractures in cases 1 and 2, and left proximal metaphyseal radial and ulnar fractures in case 3. All cases had closed long-bone fractures with short juxta-articular fracture segments. Under fluoroscopic guidance, proper placement of the ring fixation elements was confirmed during surgery. Two or three rings were used to stabilize fractures with traditional circular external skeletal fixators (CESF). Postoperative radiographs showed acceptable alignment and apposition of the previously identified fracture. Time to radiographic union ranged from 5 to 14 weeks and there were no signs of implant failure or pin tract infection. Functional outcomes were excellent in all cases. CESF can be successfully used to reduce short juxta-articular fractures in which bone plates or external skeletal fixation cannot be applied.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.641-654
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• 1996

In infectious disease, invasion of host tissue by bacteria or their products frequently induces a wide variety of inflammatory and immunopathologic reaction. Evidence indicates that cytokines are involved in the initiation and progression of chronic inflammatory diseases, such as periodontitis. Interleukin-6, which is a multifunctional cytokine, has important roles in acute and chronic inflammation and may also be implicated in bone resorption. Periodontal diseases are characterized by chronic inflammation of the periodontium with alveolar bone resoption. A principal driving force behind this response appears to lie in the immune system's response to bacteria. Many of the cell components which have been shown to function as virulence factors in gram-negative bacteria are associated with the bacterial surface. Of these, lipopolysaccharide has been characterized as one that mediates a number of biological activities which can lead to the destruction of host tissue. Non-steroidal antiinflammatory drug is used for reduce inflammation, and most of NSAIDs inhibit prostaglandine $E_2$ production, but it is shown that $PGE_2$ production is stimulated by IL-1 in recent study. So, the influence of other cytokines except $PGE_2$ on periodontium can not be avoided. Therefore, new antiinflammatory drug is needed. Rhizoma coptidis is used in oriental medicine for anti-inflammation and antiseptics. In this present study, we examined the IL-6 release in periodontal ligament cells treated with the lipopolysaccharide, and also the effect of rhizoma coptidis on cellular activity and IL-6 production of periodontal ligament cells. To evaluate the effect of rhizoma coptidis on cellular activity, the cells were seeded at a cell density of $1{\times}10^4$ cells/well in 24-well culture plates. After one day incubation, 1-6, 10-9 and 10-12 g/ml of rhizoma coptidis and 5, $10{\mu}g/ml$ of LPS were added to the each well and incubated for 1 and 2 days, respectively. Then, MTT assay were carried out. To evaluate the effect of rhizoma coptidis on IL-6 production, the cells were seeded at a cell density of $1.5{\times}10^4$ cells/well in 24-well culture plates. After one day incubation, 10-9 g/ml of rhizoma coptidis and 5, $10{\mu}g/ml$ of LPS were added to the each well and incubated for 3, 6, 12 and 24 hours. Then, amounts of IL-6 production is measured by IL-6 ELISA kit used. The results were as follows : 1. Rhizoma coptidisrbelow to ($10^{-6}g/ml$) significantly increaed cellular activity of periodontal ligament cells than control. 2. Rhizoma coptidist ($10^{-9}g/ml$) significantly increased cellular activity of LPS($5{\mu}g/ml$)-treated periodontal ligament cells than control. 3. LPS(5 and $10{\mu}g/ml$) significantly increased IL-6 production of periodontal ligament cells than control. 4. Rhizoma coptidis($10^{-9}g/ml$) decreased IL-6 production of LPS ($5{\mu}g/ml$)-treated periodontal.ligarnent cells than LPS only tested group. These findings suggest that stimulation of the IL-6 release of periodontal ligament cells by LPS may have a role in the progression of inflammation and alveolar bone resoption in periodontal disease, and that inhibition of the IL-6 release of cells and stimulation of cellular activity by rhizoma coptidis may help the periodontal regeneration.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.85-97
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• 1998

The purpose of this study was to observe the effects of sodium fluoride on the bony repair and regeneration processes after the rapid palatal expansion in the growing dogs. Eighteen dogs were divided into experimental and control groups. They were in the late mixed dentition. The rapid Palatal expansion was undertaken in all the animals($180^{\circ}$ turn/day) for ten days. The animals were sacrificed on 0, 15 and 45 days after the finish of expansion. One mg NaF/kg of body weight/day were given orally to the experimental group. Blood samples were drawn before and after expansion and the se겨m calcium, phosphate and alkaline phosphatase level were measured. The undecalcified bone section of midpalatal suture area was made, and observed under the light microscopy The results were as follows ; 1. The day after expansion, the infiltration of inflammatory cells were prominent and the new bone formation started at the edges of the two palatal plates bodering the midpalatal suture in both groups. Especially, the newly formed osteoid were very extensive and the osteoblasts lining the osteoid were very active in the experimental group. 2. At fifteen days after expansion, the active osteoblasts lining the osteold at the surface of trabecular bony spicules and active new bone formation were observed in the both groups. However, the cellular activity and new bone formation were more prominent In the experimental group. 3. At forty five days after expansion, the continuous osteoid and new bone formation and active osteoblasts were observed in the experimental group. But these phenomena were not observed in the control group. In the control group, the numerous osteoclasts were adjacent midpalatal suture and the bony remodeling process was begun. The serum alkaline phosphatase level was maintained highly in the experimental group, but decreased in the control. According to the above results, the author reached the conclusion that sodium fluoride has the stimulation effects on the osteoid production of the osteoblasts during the healing process after the rapid Palatal expansion more continuously.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.4
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• pp.154-160
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• 2014

Purpose: The efficiency of an anchor plate placed during orthognathic surgery via minimal presurgical orthodontic treatment was evaluated by analyzing the mandibular relapse rate and dental changes. Methods: The subjects included nine patients with Class III malocclusion who had bilateral sagittal split osteotomy at the Division of Oral and Maxillofacial Surgery, Department of Dentistry in Ajou University Hospital, after minimal presurgical orthodontic treatment. During orthognathic surgery, anchor plates were placed at both maxillary buttresses. The anchor plates were used to move maxillary teeth backward and for maximum anchorage of Class III elastics to minimize mandibular relapse during the postoperative orthodontic treatment. The lateral cephalometric X-ray was taken preoperatively (T0), postoperatively (T1), and one year after the surgery (T2). Seven measurements (distance from Pogonion to line Nasion-Nasion perpendicular [Pog-N Per.], angle of line B point-Nasion and Nasion-Sella [SNB], angle of line maxilla 1 root-maxilla 1 crown and Nasion-Sella [U1 to SN], distance from maxilla 1 crown to line A point-Nasion [U1 to NA], overbite, overjet, and interincisal angle) were taken. Measurements at T0 to T1 and T1 to T2 were compared and differences tested by standard statistical methods. Results: The mean skeletal change was posterior movement by $13.87{\pm}4.95mm$ based on pogonion from T0 to T1, and anterior movement by $1.54{\pm}2.18mm$ from T1 to T2, showing relapse of about 10.2%. There were significant changes from T0 to T1 for both Pog-N Per. and SNB (P<0.05). However, there were no statistically significant changes from T1 to T2 for both Pog-N Per. and SNB. U1 to NA that represents the anterior-posterior changes of maxillary incisor did not differ from T0 to T1, yet there was a significant change from T1 to T2 (P<0.05). Conclusion: This study found that the anchor plate minimizes mandibular relapse and moves the maxillary teeth backward during the postoperative orthodontic treatment. Thus, we conclude that the anchor plate is clinically very useful.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.4
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• pp.367-376
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• 1997

The 234 patients who received treatment of midfacial fractures at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital from Jan. 1, 1992 to Dec. 31, 1996 were analyzed clinicostastically. Results obtained were as follows ; Male predominated over females by a ratio of 5.3 to 1. The frequently developing age groups were first 3rd (25%), 4th (21%) and the 2nd (18%) decade on succession. The peakest month was the August (16%), and May (11%), September (9%), October (9%). When it comes to the reasons for in-patients, traffic accident was predominant to 38%. In the 234 cases of midfacial fractures, zygomaticomaxillary complex fracture was the most by 37%. The most common with injury show that facial laceration marked by 49%, neurologic injury 24%, and mandibular fracture 20% each by each. About the time from injury onset to operation, 55% of cases were less than a week while the others (45%) more than a week. 3 plates were used for operation : 2 for zygoma or maxilla fracture and 3 for zygomatiomaxillary complex fracture. especially 4 for Le Fort I fracture, 5.5 for Le Fort I, II ; I, III ; II, III fracture, 7 for Le Fort I,II,III fracture were used. 20 patients (8%) appealed their complication and the most common was reported as infection. Above results suggest that early diagnosis and treatment of fracture site, systemic condition and associated injuries are necessary, and coorperative treatment with medical department should be performed.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.163-180
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• 2001

The aim of this study was to evaluate the effects of chitosan coating on the attachment, proliferation, functional and morphological change of periodontal ligament cells. Primary human periodontal ligament cells were cultured in dulbecco's modified Eagle's medium with 10% fetal bovine serum and 1% antibiotics. In experimental group, cells of 4th to 7th passage were inoculated in the multiwell plates coated with chitosan in concentration of 0.22, 0.2, and $2mg/m{\ell}$. Cell counting and MTT assay were done after 0.5, 1.5, 3, 6 and 24 hours of incubation to evaluate the cell attachment, and then after 2 and 7 days of culture to evaluate the cell proliferation. The alkaline phosphatase activity was measured after 4 and 7 days of culture and the ability to produce mineralized modules was evaluated after 21 days of culture. The results were as follows : 1. The morphology of periodontal ligament cells on the chitosan coating was round or spheric. Round cells were aggregated after 6 hours of culture. Aggregated cells on the chitosan coated surface showed nodule-like appearance after 24 hours of culture and not achieved confluency at 7 days. 2. During early period of culture, the attachment of periodontal ligament cells were inhibited by chitosan coating. Inhibition of cell attachment tended to increase with the concentration of chitosan. 3. At the chitosan concentration of 0.02 and $0.2mg/m{\ell}$, periodontal ligament cells were more rapidly proliferated at 7 days, compared to the control group. At the concentration of $2mg/m{\ell}$, the proliferation of periodontal ligament cells was inhibitied(p<0.01). 4. Alkaline phosphatase activity of periodontal ligament cells was increased in chitosan coated group, especially at the concentration of $0.02mg/m{\ell}$after 4 days of culture.5. Periodontal ligament cells produced mineralized nodules on chitosan coated wells without the addition of mineralized nodule forming materials (ascorbic acid, ${\beta}-glycerophosphat$, dexamethasone). With the addition of mineralized nodule forming materials, periodontal ligament cells produced more mineralized nodules at the concentration of $0.02mg/m{\ell}$, compared to the control. In summary, the attachment, proliferation, cell activity, and alkaline phosphatase activity of periodontal ligament cells depended on the concentration of coated chitosan. Chitosan stimulated mineralized nodule formation by periodontal ligament cells. At the appropriate concentration($0.02mg/m{\ell}$), chitosan could increase alkaline phosphatase activity and stimulate the formation of mineralized nodule by periodontal ligament cells. These results suggest that chitosan can be used as an adjunct for bone graft material, and the matrix of tissue engineering for periodontal regeneration, especially bone regeneration.