• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.362-374
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• 2007

Statement of problem. The intial stability for osseointegration of implant has been an interesting factor. Especially, in the case of poor bone quality or immediately loaded implant, various strategies have been developed focusing on the surface of materials to improve implant fixation to bone. The microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Purpose. The aims of this study are to perform a histologic and histomorphometric comparison of the healing characteristics of three different surfaces and the comparison of resonance frequency analysis (RFA) values measured by $Osstell^{TM}$ and perio-test values (PTV) measured by Periotest. Material and methods. A total of 24 screw titanium implants (Dentium Co., Seoul, Korea) with 6mm in length and 3.4mm in diameter, were placed in the mandible of 4 beagle dogs. Implants were divided into three groups following the surface treatment methods: Group I is machined(control group). Group II is anodically oxidized. Group III is coated 500nm in thickness with hydroxyapatite(HA) by ion beam assisted deposition(IBAD) on the anodized oxidization. Bone blocks from 2 dogs were caught after 3 weeks of covered healing and another blocks from 2 dogs after 6 weeks. RFA values and PTV were measured right after insertion and at 3 and 6weeks. Histomorphometric analysis was made with Kappa Image Base System to calculate bone-to-implant contact (BIC) and bone area inside the threads. Pearson's correlation analyses were performed to evaluate the correlation between RFA and PTV, BIC and bone area ratio of three different surfaces at 3 and 6 weeks. Results. 1) In all surface treatment methods, the RFA values decreased and the PTV values increased until 6 weeks in comparison to initial values. 2) At 3 weeks, no significant difference was found from bone-to-implant contact ratio and bone area ratio of three different surface treatment methods(P>0.05). However, at 6 weeks, different surface treatment methods showed significantly different bone-toimplant contact ratio and bone area ratio(P<0.05). 3) In the implants with the IBAD on the anodic oxidization, significant difference was found between the 3 weeks and the 6 weeks bone area ratio(P<0.05). 4) Correlation was found between the RFA values and the bone area ratio at 3 and 6 weeks with significant difference(P<0.05). Conclusions. These results indicate that the implants with the IBAD on the anodic oxidization may have a high influence on the initial stability of implant.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.576-580
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• 2003

A 7-year-old male was refered to Department of Pediatric Dentistry, Wonkwang Dental Hospital for treatment of a traumatic injury to the teeth of the maxillary anterior region of the mouth. His right central incisor presented subluxation and root fracture, the left central incisor had suffered intrusive luxation and root fracture. The initial treatment involved reposition and fixation of the teeth with 0.5mm stainless steel wire and composite resin. The patient was submitted for clinical and radiographic fallow-up. After 4 years, radiographically the right central incisor seemed to be healed by hard tissue union and showed to be indistinct fracture line, intact lamina dura. The left central incisor radiographically was healed by interposition of bone and connective tissue and showed to be distinct horizontal fracture line separating the fragments, and pulp canal obliteration. In clinical examination, the teeth showed a normal response to elective pulp test, percussion and mobility test. Pulp survival after injuries appears to be dependent upon the type of luxation injury, age of patient, stage of root development and degree of dislocation. In this case, the two teeth with incomplete root formation were suffered different type of injury by trauma and has showed different healing aspect.

• KSBB Journal
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• v.9 no.3
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• pp.325-331
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• 1994

PGA is formed in a route of CO2 fixation of RuBP catalyzed by RuBPCase, followed by reduction of the PGA by NADH to GAP This reduction is enhanced in an anionic micellar solution(SDS), in which NADH is distributed in the aqueous and the micellar pseudophases in a given ratio. This micellar bounded NADH reacts to PGA, and in higher micellar concentration than $1.25{\times}10^{-2}M$, most of NADH is oxidized to NAD+ by PGA. On the other hand, in the solutions of the positive ionic(CTABr), zwitter ionic(Chaps) and nonionic (Brij and Triton X-100) micelles, the reactions are also enhanced and the concentrations of NADH reach minima with micellar concentrations. Such minima are typical of micellar catalyzed bimolecular reactions, and the fall in concentrations of the reductant followed by a gradual increase is charataristic of reactions of hydrophobic substrates: that is, the reductions of PGA by NADH are sharply enhanced in a range of the lower micellar concentrations, and NADH amounts in ca. $1.25-2.50{\times}10^{-3}M$ micellar solutions are reached to minima, followed by gradual increases of the reductant concentration.

• Clean Technology
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• v.20 no.4
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• pp.349-353
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• 2014

Succinic acid is an important precursor in industries producing biopolymers, pharmaceutical and food additives and green solvents. However, due to the high price of petroleum and the global $CO_2$ emission, the biological production of succinic acid from renewable biomass is a novel process due to the fixation of $CO_2$ into succinate during fermentation. In this study, aqueous two phase systems based on imidazolium ionic liquids/$K_2HPO_4$ were used as an effective separation and concentration process for succinic acid. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of imidazolium ionic liquids to aqueous $K_2HPO_4$ solutions in the presence of succinic acid. It can be found that the ability of imidazolium ionic liquids for phase separation followed the order [HMIm][Br]${\fallingdotseq}$[OMIm][Br]>[BMIm][Br]>[EMIm][Br]. The maximum value of extraction efficiency for succinic acid was about 90% and the amount of coextracted water into top phase is proportional to the chain length of cation in imidazolium ionic liquids. It was concluded that the aqueous two phase systems composed of imidazolium ionic liquids/$K_2HPO_4$ was effective for the selective extraction and concentration of succinic acid.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.187-198
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• 2001

Background: The purpose of this study was to evaluate the relationship between variable factors and clinical results following the operative treatment of the tibial plateau fractures. Materials and Methods: The clinical and radiological analysis was performed on 29 cases of the tibial plateau fractures who had been treated with operative treatment and followed up for more than 1 year from January 1991 to December 1997. The analysis of clinical results was performed dividing into age, cause of injury, fracture type of Schatzker classification, associated soft tissue injury and method of operative treatment. Results: According to Schatzker classification, 2 cases(6.9%) were type I, 11 cases(37.9%) were type II, 1 case(3.5%) was type III, 5 cases(17.2%) were type IV, 4 cases(13.8%) were type V, and 6 cases(20.7%) were type VI. In all cases, bony unions were obtained. According to Blokker evaluation, 23 cases(79.3%) of 29 cases were acceptable. Conclusion: We could expect good clinical results if early knee joint mobilization following minimal invasive open reduction and internal fixation could be obtained. Bad clinical results were related with young age group under 30, more than Schatzker classification type IV of high energy trauma and associated injury of anterior cruciated ligment or meniscus.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.108-109
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• 2003

Ursolic acid (UA) and Oleanolic acid (ONA), known as urson, micromerol, prunol and malol, are pentacyclic triterpenoid compounds which naturally occur in a large number of vegetarian foods, medicinal herbs, and plants. They may occur in their free acid form or as aglycones for triterpenoid saponins, which are comprised of a triterpenoid aglycone, linked to one or more sugar moieties. Therefore UA and ON A are similar in pharmacological activity. Lately scientific research, which led to the identification of UA and ONA, revealed that several pharmacological effects, such as antitumor, hepatoprotective, anti-inflammatory, antimicrobial, and anti-hyperlipidemic could be attributed to UA and ONA. Here, we introduced the effects of UA and ONA on acute barrier disruption and normal epidermal permeability barrier function. To clarify the effects of UA and ONA on skin barrier recovery, both flank skin of 8-12 weeks hairless mice were topically treated with samples (2mg/ml) after tape stripping, then measured recovery rate using TEWL on hairless mice. The recovery rate increased in UA and ONA treated groups at 6h more than 20% compared to vehicle treated group (p <0.05). For verifying the effects of UA and ONA on normal epidermal barrier, hydration and TEWL were measured for 1 and 3 weeks after UA and ONA applications (2mg/ml per day). We also investigated the features of epidermis and dermis using electron microscopy (EM) and light microscopy (LM). Both samples increased hydration compared to Vehicle group from 1 week without TEWL alteration (p<0.005). EM examination using Ru04 and OsO4 fixation revealed that secretion and numbers of lamellar bodies and complete formation of lipid bilayers were most prominent (ONA$\geq$UA>Vehicle). LM finding showed that stratum corneum was slightly increased and especially epidermal thickening and flattening was observed (UA>ONA>Vehicle). Using Masson-trichrome and elastic fiber staining, we observed collagen thickening and elastic fiber increasing by UA and ONA treatments. In vitro results of collagen and elastin synthesis and elastase inhibitory experiments were also confirmed in vivo findings. This result suggested that the effects of UA and ONA related to not only skin barrier but also collagen and elastic fibers. Taken together, UA and ONA can be relevant candidates to improve barrier function and pertinent agents for cosmetic applications.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.35.1-35.7
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• 2018

Background: After the resection at the mandibular site involving oral cancer, free vascularized fibular graft, a type of vascularized autograft, is often used for the mandibular reconstruction. Titanium mesh (T-mesh) and particulate cancellous bone and marrow (PCBM), however, a type of non-vascularized autograft, can also be used for the reconstruction. With the T-mesh applied even in the chin and angle areas, an aesthetic contour with adequate strength and stable fixation can be achieved, and the pores of the mesh will allow the rapid revascularization of the bone graft site. Especially, this technique does not require microvascular training; as such, the surgery time can be shortened. This advantage allows older patients to undergo the reconstructive surgery. Case presentation: Reported in this article are two cases of mandibular reconstruction using the ready-made type and custom-made type T-mesh, respectively, after mandibular resection. We had operated double blind peer-review process. A 79-year-old female patient visited the authors' clinic with gingival swelling and pain on the left mandibular region. After wide excision and segmental mandibulectomy, a pectoralis major myocutaneous flap was used to cover the intraoral defect. Fourteen months postoperatively, reconstruction using a ready-made type T-mesh (Striker-Leibinger, Freibrug, Germany) and iliac PCBM was done to repair the mandible left body defect. Another 62-year-old female patient visited the authors' clinic with pain on the right mandibular region. After wide excision and segmental mandibulectomy on the mandibular squamous cell carcinoma (SCC), reconstruction was done with a reconstruction plate and a right fibula free flap. Sixteen months postoperatively, reconstruction using a custom-made type T-mesh and iliac PCBM was done to repair the mandibular defect after the failure of the fibula free flap. The CAD-CAM T-mesh was made prior to the operation. Conclusions: In both cases, sufficient new-bone formation was observed in terms of volume and strength. In the CAD-CAM custom-made type T-mesh case, especially, it was much easier to fix screws onto the adjacent mandible, and after the removal of the mesh, the appearance of both patients improved, and the neo-mandibular body showed adequate bony volume for implant or prosthetic restoration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.334-347
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• 2006

The aim of this study is to evaluate the reasonableness of the medical fee on oral and maxillofacial surgery field according to surgeon's opinions and actual conditions. The medical fee has significant influence on hospital income, the supply and distribution of medical manpower, quality and facilities of medical services. Questionnaire survey was sent to 86 oral and maxillofacial surgeons who worked more than 3 years in general hospital. Among them, 25 doctors replied the 109 answers survey and the average of treatment time and physician work relative value on each category was calculated. And the health insurance cost (that has been applied since 2003) was compared with the questionnaire results. And finally we investigated items that health insurance system did not include in oral and maxillofacial field but actually performed in oral and maxillofacial surgery clinic. The result was that the medical fee did not properly reflect physician work relative value of actual treatments. In case of complicated extraction, work relative value needed 3.5 times enhancement of present value. For simple impacted tooth extraction 1.8 times, for impacted tooth extraction including odontomy 1.7 times, and for fully impacted tooth more than 2/3 of it located into the alveolar bone, 1.8 times enhancement needed. In respect of the present physician work relative value, hemimandibulectomy with neck lymph node dissection for the malignancy is appropriated as 3.3 times of open reduction and internal fixation for the mandibular fracture, but the questionnaire result showed 25 times discrepancy. In conclusion, this research shows the need for intervention that health insurance included items and legal relative medical value must act in union with treatment in clinic to reduce the imbalance between them.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.1
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• pp.26-34
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• 2003

Intraoral Vertical Ramus Osteotomy,along with Sagittal Split Ramus Osteotomy,is an popular surgical technique performed on mandibular prognathism. However Intraoral Vertical Ramus Osteotomy has been suspected for an initial mobilization at the healing phase of segment because it does not employ the rigid fixation between segments. To execute a study on the healing phase of segment after Intraoral Vertical Ramus Osteotomy on the horizontal plane, 102 patients (204 parts) who were diagnosed mandibular prognathism and took Intraoral Vertical Ramus Osteotomy at the Yonsei University dental hospital were observed during the period of before operation, immediately postoperation, 1 month, 3 months, 6 months, and 12 months. The change in the width of segment and horizontal angle of proximal segment and condylar head on the Submentovertex Cephalogram taken from those patients represented following results. 1. The width of proximal and distal segment decreased with the lapse of time. It decreased into 84.5% between immediate postoperative and 6M and even continued to decrease till 12M. 2. The horizontal angle of the proximal segment did medial rotation according as the lapse of time and rigorously continued till 3M. The rotation angle of condylar head indicated its tendency of recurrence to the original position but the entire recurrence was not allowed. The bigger an initial angle was, the higher was the tendency of recurrence after the operation while the rotation angle remained still bigger. 3. After grouping into group 1, group 2,and group 3 based on the extent of the variation of rotation angle of condylar head at immediate postoperative, the variation of rotation angle was measures in each group. The result presented that the initial rotation angle of condylar head had correlation with that of proximal segment but had no relation with the extent of setback of the mandible. However a quantitative analysis alone is not a sufficient method for analyzing the healing phase of segment on the horizontal plane.Therefore a multilateral analysis using 3 dimensional data such as CT is recommendable for the future study.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.97-102
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• 2004

In order to find out the rate of error according to intraoral standard radiographic techniques, this study analyzed 3,251 standard films, and conducted a questionnaire with 120 Daegu Health College students who have used the bisecting angle technique and the paralleling technique. Followed are the results of the study: 1. The rate of error was the highest in canine from both maxilla and mandible when used by the bisecting angle technique. 2. The rate of error was the highest in premolar from both maxilla and mandible when used by the paralleling technique. 3. The technical error was occurred most frequently in elongation. 4. The rate of error and distortion was higher in the bisecting angle technique than in the paralleling technique. 5. The processing error was occurred most frequently in light film. 6. In applying radiographic techniques, the subjects indicated that the vertical angulation of central radiation in the bisecting angle technique and the oral fixation of film holder in the paralleling technique were the most difficult.