• The Journal of Korean Academy of Prosthodontics
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• v.54 no.4
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• pp.379-386
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• 2016

Purpose: The present study aims at researching the subjective satisfaction of patients who have experienced both conventional impression taking and digital impression taking to measure the possibility of wide clinical application of digital impression. Materials and methods: The study surveyed 170 adult patients over the age of 20, between October 2015 and April 2016, who voluntarily consented to participation and who experienced both conventional impression and digital impression at five dental hospitals that use intraoral digital impression. A total of 128 surveys were used for data analysis, involving frequency analysis, multiple response frequency analysis, descriptive statistics, and contingency table analysis, with the significance level set at 0.05. Results: Responses on the reason for taking impressions using the digital method appeared in the order of 'for implant treatment' (43.8%), 'for crown treatment' (30.5%), and 'for inlay treatment' (15.6%). Patients satisfaction was higher for digital impression taking than conventional impression taking (P<.05). As the preferred choice of impression, digital impression (60.2%) was higher than conventional impression (11.7%). Responses on the reason for choosing digital impression taking appeared in the order of 'no vomiting reflex' (35.1%), 'reliability of 3D digital scanning' (33.8%), and 'short time' (33.8%). Conclusion: The patients preferred digital impression taking to conventional impression taking in terms of satisfaction.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.295-300
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• 2009

Statement of problem: As the number of elders is growing with the advancement of medicine, partially or fully edentulous patients have increased. Medically compromised conditions are common in the older population so that it should be taken into account in prosthetic treatment planning as well as their economic conditions. In the older patients, removable prosthesis has been preferred to implant prosthesis. However, cast metal based removable partial dentures also has several limitations. Purpose: In this report, we present several cases of Valplast$^{(R)}$ flexible denture which were fabricated in patients who had medically compromised conditions or whose remaining teeth showed a relatively poor prognosis. Results & Conclusion: This article describes an alternative treatment for a partially edentulous patient with mouth opening limitation, after cancer surgery, compromised general condition and questionable remaining teeth. In these patients, Valplast$^{(R)}$ flexible denture was used because of its unique characteristics and the results were all satisfactory. Patients had 1-2 check-up and there were no postoperative pain or fracture of denture up to now.

• Imaging Science in Dentistry
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• v.39 no.3
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• pp.149-156
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• 2009

Purpose : The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. Materials and Methods : We devised a patient-specific stent for patient-to-image registration and navigation. Three-dimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. Results : The accuracy over 8 anatomical landmarks showed an overall mean of $0.56{\pm}0.16\;mm$. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. Conclusion : The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.129-142
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• 2002

Epithelial-mesenchymal interaction plays a important role in cell growth and differentiation. This interaction is already well known to have an importance during the organ development as well as cell growth and differentiation. However, in vitro experimental model is not well developed to reproduce in vivo cellular microenvironment which provide a epithelial-mesenchymal interaction. Because conventional monolayer culture lacks epithelial-mensenchymal interaction, cultivated cells have an morphologic, biochemical, and functional characteristics differ from in vivo tissue. Moreover, it's condition is not able to induce cellular differention due to submerged culture condition. Therefore, the aims of this study were to develop and evaualte the in vitro experimental model that maintains epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally reconstituted oral keratinocytes by histological and immunohistochemical analysis. The results were as follow; 1. Gingival keratinocytes reconstituted by three-dimensional organotypic culture revealed similar morphologic characteristics to biopsied patient specimen showing stratification, hyperkeratinosis, matutation of epithelial architecture. 2. Connective tissue structure was matured, and there is no difference during stratification period of epithelial 3-dimensional culture. 3. The longer of air-exposure culture on three-dimensionally reconstituted cells, the more epithelial maturation, increased epithelial thickness and surface keratinization 4. In reconstitued mucosa, the whole epidermis was positively stained by anti-involucrin antibody, and there is no difference according to air-exposured culture period. 5. The Hsp was expressed in the epithelial layer of three-dimensionally cultured cells, especially basal layer of epidermis. The change of Hsp expression was not significant by culture stratification. 6. Connexin 43, marker of cell-cell communication was revealed mild immunodeposition in reconstitued epithelium, and there is no significant expression change during stratification. These results suggest that three-dimensional oragnotypic co-culture of normal gingival keratinocytes with dermal equivalent consisting type I collagen and gingival fibroblasts results in similar morphologic and immunohistochemical characteristics to in vivo patient specimens. And this culture system seems to provide adequate micro-environment for in vitro tissue reconstitution. Therefore, further study will be focused to study of in vitro gingivitis model, development of novel perioodntal disease therapeutics and epithelial-mensenchymal interaction.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.253-261
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• 2015

Chronic periodontitis involves subsequent loss of teeth, and if left untreated, can lead to adjacent teeth drifting and supraeruption of the rest dentition. Careful consideration has to be given when deciding extraction of remaining teeth in treatment of periodontally compromised dentitions. For tooth-supported fixed partial dentures or removable partial dentures, periodontally compromised teeth are extracted due to possible early failure from functional overload, but for implant restoration, the teeth could be used as supports for fixed partial dentures because implants can reduce overload on teeth. The remaining natural teeth can help clinicians restoring vertical dimension and normal occlusal plane in full mouth rehabilitation because it conserves patients' proprioceptive response. This clinical report describes treatment of a patient who has a few remaining teeth and supraeruption of the rest dentition from severe chronic periodontitis. Satisfactory clinical result was achieved with full mouth rehabilitation using a few teeth and implants.

• 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 Periodontal and Implant Science
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• v.30 no.1
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• pp.11-27
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• 2000

The purpose of this study was to evaluate the clinical effects of Dipotassium glycyrrhizinate, Allantoin, Hinokitiol, Cetylpyridinium chloride containing gel($Dentheth^{(R)}$) on periodontitis. 41 patients with sites having pocket depth of 4-6mm were selected for the study. We classified 2 groups which consisted of 21 patients in the test group(exp.) and 20 patients in the control(placebo) respectively. Following a baseline examination, plaque and calculus were removed and then the experimental gel were handed out to the patients and topical application regimens were initiated. During the 4-week experimental period, pocket depth, bleeding on probing, gingival index, plaque index as a clinical parameters were measured in the baseline, 2 weeks, 4 weeks respectively. A questionnaire was delivered to each patients in 2 weeks, 4 weeks respectively. The results were as follows : 1. Probing pocket depth showed a significant difference in the Exp. group compared with the control group in the changes from baseline to 2 weeks(p<0.05), but there was no significant difference between the groups in the changes from baseline to 4 weeks, from 2 weeks to 4 weeks(p<0.05). 2. The Exp. group showed a significant difference compared with the control group in the changes from baseline to 2 weeks, from baseline to 4 weeks, from 2 weeks to 4 weeks in bleeding on probing(p<0.05). 3. The gingival index showed a significant difference compared with the control group in the changes from baseline to 2 weeks, from baseline to 4 weeks, from 2 weeks to 4 weeks after 4 weeks use of a gel(p<0.05). 4. The plaque index showed a significant difference in the Exp. group compared with the control group in the changes from baseline to 2 weeks(p<0.05), but there was no significant difference between the groups in the changes from baseline to 4 weeks, from 2 weeks to 4 weeks(p<0.05). 5. A questionnaire was consisted of 5 kinds as to bleeding, pus discharge, pain, burning sensation, patient's satisfaction and all of the questions showed a significant difference compared with the control group in the changes from 2 weeks to 4 weeks(p<0.05). 6. During the 4-week experimental period, important side-effects were not finded out, but each groups had one patient appealed nausea or discomfort respectively. These results indicate that application of periodontitis medical gel was useful as an additional aid of mechanical treatment.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.649-659
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• 2005

The purpose of this study was to quantify and compare the level of MMP-1 in the healthy or inflamed gingival tissue of patients with or without type 2 diabetic mellitus. We investigated whether mean amount of MMP-1 was changed by chronic periodontitis and type 2 DM. Gingival tissue samples were obtained during periodontal surgery or tooth extraction. According to the patient's systemic condition & clinical criteria of gingiva, each gingival sample was divided into the three group. Group 1(n=8) was clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from systemically healthy 8 patients. Group 2(n=8) was inflamed gingiva from patients with chronic periodontitis. Group 3(n=8) was inflamed gingiva from patients with chronic periodontitis and type 2 diabetes. Tissue samples were prepared and analyzed by Western blotting. The quantitative analysis of MMP-1 was performed using a densitometer and statistically analyzed by ANOVA. MMP-1 was expressed in all samples and an increased MMP-1 level was observed in group 2 compared to group 1 and decreased MMP-1 level was found group 3 compared to group 2, but the differences among 3 groups were not statistically significant. In conclusion, this study demonstrated that MMP-1 levels of inflamed gingiva of systemically healthy patient(group 2) were higher than normal gingiva of systemically health patients and although the severity of gingival inflammation in group 2 and 3 were similar, MMP-1 expression was decreased in diabetic patients than systemically healthy periodontal patients.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.623-628
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• 2009

Purpose: In cases where nasal fractures involve frontal process of maxilla or perpendicular plate of ethmoid, 4 - 5 days of nasal packing may not provide sufficient support for avoiding displacement after packing removal. Therefore a single Kirschner - wire(K - wire) is used as an internal splint when nasal fractures involve the above two areas. Methods: Thirty five patients during the last 3 practical years were treated with a K -wire pinning according to the anatomic locations of nasal fractures. We performed a retrospective study using 13 nasal fractures out of total 35 patients. Among 13 cases, 10 patients involved frontal process of maxilla, and 3 patients were diagnosed as bilateral nasal side wall fractures accompanied with fractures of perpendicular plate of ethmoid. One patient of the last three cases had been augmented with dorsal silicone implant long before the trauma. We analyzed the anteroposterior displacement of key stone area and the width between both lateral walls by comparing immediate postoperative radiographs with 2 month follow - ups. To reduce the errors, the same measurements were taken by two different inspectors, and the mean of each inspector's measurements was compared. Patient satisfaction was analyzed using a questionnaire regarding the esthetic and functional outcomes. Results: Ten patients underwent a longitudinal K - wire fixation in submucoperiosteal plane underneath the frontal process of maxilla. And three patients underwent a transverse K - wire fixation from the one side of lateral wall to the perpendicular plate of ethmoid and to the other side of lateral wall. The mean postoperative anteroposterior displacement of the key stone area measured by two inspectors were 1.84% and 3.06%; mean narrowing of bony pyramid were 1.33% and 1.48%, respectively. Subjective satisfaction scores regarding the esthetic appearance and the maintenance of nasal shape compared with immediate post - operative state with the long term ones were not different (p>0.05). Conclusion: K - wire pinning after closed reduction is a reliable and useful method for the treatment of nasal fractures involving frontal process of maxilla or perpendicular plate of ethmoid. This is because it achieves longer intranasal support after reduction. This method also leaves conspicuous external scar, and minimal soft - tissue injury.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.531-537
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• 2009

Purpose: Alveolar bone grafting has become an essential process in the treatmemt of alveolar cleft patient for stabilization of the maxillary arch, elimination of oronasal fistula, the reconstruction of the soft tissue nasal base support, and creation of bony support for tooth eruption for implant. The use of Autologous iliac cancellous bone is preferable because of the adequate quantity and high osteoinductive potential. However, even with iliac bone, insufficient osteoregeneration and absorption occur due to several factors such as the patient's age, cleft width, functional stress, and others. In order to increase osteoregeneration where the iliac bone is placed, the present study is associated with bone marrow aspirate (BMA). The experimental study evaluated the efficacy of osteoregeneration in normal cleft rabbits when alveolar bone grafting was performed with autologous iliac corticocancellous bone. Methods: Twenty - four New Zealand White rabbits were divided randomly into 2 groups (BMA, control). All animals underwent harvesting of corticocancellous bone graft from the right posterior iliac crest via standard surgical technique. $1m{\ell}$ of BMA were obtained by scraping the needle and aspirate with $10m{\ell}$ syringe from the contralateral iliac bone wall. The muco - periosteal flap on the palate was elevated. A mixture of Equal bone's volumes with BMA and saline as its control was inserted into the cleft. Animals were sacrificed at 2, 4, and 8 weeks and maxilla was harvested for dental peri - apical X-ray, bone matrix density (BMD),and histologic analysis. Result: BMD of regenerated bone to the cleft in the rabbits was higher than that of the control rabbits. X-ray, histologic analysis showed that increased osteoregeneration and low absorption rate were observed in the BMA group. Conclusion: Our experimental study showed BMA enhanced the osteoregeneration and survival rate of alveolar bone grafting. BMA is easy to extract & cost - time effective. So it can be an effective enhancers for bone grafting mixtures.