• 한국정밀공학회지
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• 제26권12호
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• pp.138-145
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• 2009

Custom medical treatment is being widely adapted to lots of medical applications. A technology for 3D modeling is strongly required to fabricate medical implants for individual patient. Needs on true 3D CAD data of a patient is strongly required for tissue engineering and human body simulations. Medical imaging devices show human inner section and 3D volume rendering images of human organs. CT or MRI is one of the popular imaging devices for that use. However, those image data is not sufficient to use for medical fabrication or simulation. This paper mainly deals how to generate 3D geometry data from those medical images. A new image processing technology is introduced to reconstruct 3D geometry of a human body vacancy from the medical images. Then a surface geometry data is reconstructed by using Marching cube algorithm. Resulting CAD data is a custom 3D geometry data of human vacancy. This paper introduces a novel 3D reconstruction process and shows some typical examples with implemented software.

• Journal of Periodontal and Implant Science
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• 제40권4호
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• pp.164-171
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• 2010

Purpose: This study compared the total antioxidant status (TAS) and superoxide dismutase (SOD) activity in the saliva of periodontally compromised patients before and after scaling and root planing (SRP) to assess their diagnostic utility. Methods: Severe chronic periodontitis patient (test group) and subjects with no attachment loss, sites showing a 3 mm or more probing depth and a sulcus bleeding index < 10% (control group) were enrolled in this study. Saliva sampling and clinical examination were performed at one week, one month and 3 months after SRP. The TAS and SOD activity in each patient's saliva was measured for the comparative analysis between the groups. Results: In the test group, the TAS decreased directly after SRP. With time, it increased slightly and was relatively unchanged compared to the baseline. In the control group, the TAS also decreased immediately after SRP but increased gradually with time until 3 months. The SOD activity in the test and control subjects decreased immediately after SRP until 1 month. At 3 months, the SOD activity had increased. Both groups had a similar profile of SOD activity. However, the SOD activity of the control group was significantly higher than that of the test group at each point in time (P < 0.05). Conclusions: There was a significant difference in the total salivary antioxidant level between the periodontitis and healthy or gingivitis (control) group during the experiment period. The total antioxidant level in the saliva was higher in the patients with severe chronic periodontitis than the healthy or gingivitis control before SRP. The SOD activity of the periodontitis patients was lower than the control at each time point. These findings conclusively reveal the possible use of saliva as a diagnostic tool for periodontal health.

• Journal of Periodontal and Implant Science
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• 제32권1호
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• pp.225-234
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• 2002

The purpose of this study was to evaluate the relationship between the osteoporotic condition and periodontal condition in postmenopausal women with periodontitis. Forty three female postmenopausal patients with no systemic disease were grouped into 3 groups by their periodontal conditions; 12 mild periodontitis, 11 moderate periodontitis and 20 advanced periodontitis. From each patient, age of menopause was taken, alkaline phosphatase(ALP) and osteocalcin (OC) in blood and deoxypyridinoline (DPD) in urine were measured. Bone mineral density (BMD) of lumbar spine (L2-L4) was measured by dual energy X-ray absorptiometry. Periodontal and osteoporotic parameters were compared among the groups and correlation coefficient between them was evaluated. The blood ALP and OC levels were similar among the groups with different periodontal condition, whereas the urine DPD level and BMD were significantly lower in advanced periodontitis group than the other groups(p<0.01). Probing depth was negatively related with BMD (r=-0.5, p<0.01) and positively related with patient age and the duration of menopause (r= 0.32 and 0.35 respectively, p<0.05). Clinical attachment loss was negatively related with BMD (r=-0.66, p<0.01), and positively related with urine DPD (r= 0.37, p<0.05). These results showed that postmenopausal women with advanced periodontitis had significantly decreased bone mineral density and suggests that decreased bone mineral density in postmenopausal women could be associated with periodontal tissue breakdown.

• Journal of Periodontal and Implant Science
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• 제38권1호
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• pp.91-96
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• 2008

Purpose: One of the main objectives of periodontal reconstructive surgery is the coverage of exposed roots that occur due to gingival recession. and Aestheic concerns are usually the reason to perform root coverage procedure. This case report was performed to evaluate the effect of root coverage using subepithelial connective tissue graft(SCTG) on Miller's Class I marginal tissue recession. Materials and Methods: One patient, with two Miller's class I marginal tissue recession on both maxiallay canines, was treated with root coverage using SCTG (modified Nelson's technique). At baseline, the following measurements were recorded: 1) recession depth; 2) width of keratinized giniga. At 9, 10 months post-surgery, all clinical measurements were repeated. Result: 1) The mean root coverage from baseline to 9, 10 months post-surgery was 92.3%. 2) The mean recession depth decreased from 6.5 mm to 0.5 mm. 3) The mean width of keratinized gingiva increased from 1.25 mm to 3.5 mm. Conclusion: Within the above results, root coverage using SCTG is an effective procedure to cover Miller's class I marginal tissue recession defect. Also, patient with aesthetic concern could be satisfied with this result.

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.95-102
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• 2009

Purpose: The aim of this report is to investigate the efficacy of anorganic bovine bone xenograft(Bio-$Oss^{(R)}$) at maxillary sinus floor augmentation. Materials and methods: Two male patients who missed maxillary posterior teeth were included. They were performed maxillary sinus floor augmentation using anorganic bovine bone xenograft(Bio-$Oss^{(R)}$). After 10 or 13 months, the regenerated tissues were harvested using trephine drills with 2 or 4mm diameter and non-decalcified specimens were made. The specimens were examined histologically and histomorphometrically to investigate graft resorption and new bone formation. Results: Newly formed bone was in contact with Bio-$Oss^{(R)}$ particles directly without any gap between the bone and the particles. The proportions of newly formed bone were $23.4{\sim}25.3%$ in patient 1(Pt.1) and 28.8% in patient 2(Pt.2). And the proportions of remained Bio-$Oss^{(R)}$ were $29.7{\sim}30.2%$ in Pt.1 and 29.2% in Pt.2. The fixtures installed at augmented area showed good stability and the augmented bone height was maintained well. Conclusion: Anorganic bovine bone xenograft(Bio-$Oss^{(R)}$) has high osteoconductivity and helps new bone formation, so that it can be used in maxillary sinus floor augmentation.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.849-857
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• 2007

Purpose: The purposes of this study were to compare and quantify the expressions of RANK and RANKL in the gingival tissues of non-periodontitis patient and patients with chronic periodontitis, in order to understand the contribution of these proteins to periodontal destruction. Material and methods: 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 two groups. Group 1 (n=8) is clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from non-periodontitis patients. Group 2 (n=8) is inflammed gingiva from patients with chronic periodontitis. Tissue samples were prepared and analyzed by Western blotting. The quantification of RANK and RANKL were performed using a densitometer and statistically analyzed by Student's t-Test. Results: The expression of RANK were similar in group 1 and 2. The difference between group 1 and 2 was not statistically significant. And the mean amount of RANKL was more increased in group 2 than group 1. The difference between group 1 and group 2 was statistically significant. Conclusion: The expression level RANK didn't show any significant difference between healthy tissue from non-periodontitis patients and inflamed tissue from chronic periodontitis, but the expression level of RANKL in inflammed tissue from chronic periodontitis showed significantly increased tendency compared to healthy gingiva from non-periodontitis patients. Therefore, characteristics of RANK and RANKL in progress of chronic periodontitis would be basis of further studies in diagnostic method and treatment index of the disease.

• 구강회복응용과학지
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• 제35권4호
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• pp.228-234
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• 2019

파킨슨병은 떨림, 느려진 움직임, 근육의 경직, 자세 불안정성, 보행장애 등의 특징을 나타내는 신경변성 질환으로 도파민과 같은 신경전달 물질이 고갈되어 생긴다. 이러한 파킨슨병의 특성으로 인해 환자들은 협조적으로 치과 치료를 받는 것이 어렵다. 본 증례에서는 만성 치주염이 있는 47세의 파킨슨병 환자에게 고정성 보철 및 임플란트 식립을 통한 전악구강수복을 시행하였고 기능적, 심미적으로 만족할만한 결과를 얻을 수 있었다. 손 조작능력의 저하와 같은 파킨슨병의 특성을 고려하여 짧은 간격의 주기적인 내원을 통한 관리가 필요할 것이다.

• Archives of Plastic Surgery
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• 제47권1호
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• pp.33-41
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• 2020

Background Closed-suction drains are widely used in expander-based breast reconstruction. These drains are typically removed using a volume-based criterion. The drainage volume affects the hospital stay length and the recovery time. However, few studies have analyzed the factors that influence drainage volume after expander-based breast reconstruction. Methods We retrospectively analyzed data regarding daily drainage from patients who underwent expander-based breast reconstruction between April 2014 and January 2018 (159 patients, 176 expanders). Patient and operative factors were analyzed regarding their influence on total drainage volume and drain placement duration using univariate and multivariate analyses and analysis of variance. Results The mean total drainage volume was 1,210.77±611.44 mL. Univariate analysis showed correlations between total drainage volume and age (B=19.825, P<0.001), body weight (B=17.758, P<0.001), body mass index (B=51.817, P<0.001), and specimen weight (B=1.590, P<0.001). Diabetes history (P<0.001), expander type (P<0.001), and the surgical instrument used (P<0.001) also strongly influenced total drainage. The acellular dermal matrix type used did not affect total drainage (P=0.626). In the multivariate analysis, age (B=11.907, P=0.004), specimen weight (B=0.927, P<0.001), and expander type (B=593.728, P<0.001) were significant predictors of total drainage. Conclusions Our findings suggest that the total drainage and the duration of drain placement needed after expander-based breast reconstruction can be predicted using preoperative and intraoperative data. Patient age, specimen weight, and expander type are important predictors of drainage volume. Older patients, heavier specimens, and use of the Mentor rather than the Allergan expander corresponded to a greater total drainage volume and a longer duration of drain placement.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.337-344
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• 2018

Additive manufacturing (AM) is an alternative metal fabrication technology. The outstanding advantage of AM (3D-printing, direct manufacturing), is the ability to form shapes that cannot be formed with any other traditional technology. 3D-printing began as a new method of prototyping in plastics. Nowadays, AM in metals allows to realize not only net-shape geometry, but also high fatigue strength and corrosion resistant parts. This success of AM in metals enables new applications of the technology in important fields, such as production of medical implants. The 3D-printing of medical implants is an extremely rapidly developing application. The success of this development lies in the fact that patient-specific implants can promote patient recovery, as often it is the only alternative to amputation. The production of AM implants provides a relatively fast and effective solution for complex surgical cases. However, there are still numerous challenging open issues in medical 3D-printing. The goal of the current research review is to explain the whole technological and design chain of bio-medical bone implant production from the computed tomography that is performed by the surgeon, to conversion to a computer aided drawing file, to production of implants, including the necessary post-processing procedures and certification. The current work presents examples that were produced by joint work of Polygon Medical Engineering, Russia and by TechMed, the AM Center of Israel Institute of Metals. Polygon provided 3D-planning and 3D-modelling specifically for the implants production. TechMed were in charge of the optimization of models and they manufactured the implants by Electron-Beam Melting ($EBM^{(R)}$), using an Arcam $EBM^{(R)}$ A2X machine.

• Journal of Periodontal and Implant Science
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• 제51권2호
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• pp.77-87
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• 2021

Purpose: The aim of this study was to compare the efficacy of the tunnel technique for root coverage using a new xenogeneic acellular dermal matrix vs. connective tissue grafting (CTG) for the treatment of multiple maxillary adjacent recessions (recession type 1) at 12 months postoperatively. Methods: This study enrolled 12 patients with at least 3 contiguous, bilateral, symmetrical maxillary gingival recessions (i.e., at least 6 recessions per patient). In total, 74 recessions were treated using the modified coronally advanced tunnel (MCAT) technique combined with a novel porcine-derived acellular dermal matrix (PADM) at 37 test sites or CTG at 37 control sites. The following clinical parameters were measured: recession height, clinical attachment level, width of keratinized tissue, probing depth, recession width, gingival thickness, mean root coverage (MRC), and complete root coverage (CRC). Comparisons between test and control groups were made for pain visual analog scale scores at 14 days. Results: At 12 months, the MCAT with PADM (test) yielded a statistically significant improvement in all clinical parameters studied. MRC was significantly higher on the control sides (80.6%±23.7%) than on the test sides (68.8%±23.4%). Similarly, CRC was 48.7%±6.8% on the control sides (CTG), in contrast to 24.3%±8.2% on the test sides (PADM). Statistically significant differences were observed in favor of the control sides for all clinical parameters studied. Nevertheless, the MCAT in adjunction with PADM was clearly superior at reducing mean and maximum patient-reported postoperative pain intensity and pain duration in the first week after surgery. Conclusions: The use of PADM to treat multiple recessions improved clinical parameters at 12 months, but these outcomes were nevertheless poorer than those observed for CTG. However, PADM reduced morbidity, particularly the pain experienced by patients.