• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.61-68
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• 2006

The factors influencing long-term prognosis of teeth must be carefully considered. Among these, attachment level is strongly associated with tooth loss. The purpose of the present study was to estimate pattern of attachment loss based on attachment area in extracted teeth. 197 satisfied the criteria for assessment after staining. The protocol described by Waerhaug(l975) was performed. An indir ect method, based on digital image abstracted from digital camera and digital imaging software program, was used to calculate the root surface area and the attachment loss area. The data were analysed using SPSS. Except maxillary central incisior and mandibular canine, no statistical significant differences between each root surfaces were observed in anterior teeth. In posterior teeth, statistical significant differences in palatal surface of maxillary molar and mandibular molar compared with others were observed. Statistical significant difference in buccal surface compared with others was lowly observed in single and multi rooted. This study did not reveal progressive loss pattern of attachment area in each root surface but clarified root surface that has relative high loss rate of attachment area at extraction. Thus understanding this pattern of attachment loss is helpful for dentist to treat the periodontitis.

• 대한치과의사협회지
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• 제55권11호
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• pp.756-765
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• 2017

Purpose: The purpose of this article is to evaluate a change o bone level on the sinus floor by a bone added osteotome sinus floor elevation (BAOSFE) technique, according to the amount of deproteinized bovine bone mineral (DBBM). And Changes in augmented bone height after BAOSFE procedure were also assessed for 6 months after the implant procedure. Materials and Methods: Forty eight single implants were placed in the posterior maxilla using BAOSFE technique. The implantation sites were classified into two groups according to the amount of grafted DBBM, 0.25 group (0.25g) and 0.5 group (0.5 g). Panoramic views or cone-beam computed tomography (CBCT) were taken at the time of implant placement with BAOSFE and after at least 6 months to assess the bone level changes in the elevated sites with DBBM. Results: Alveolar bone level around all implants was stable clinically and radiographically during the follow-up. Mean augmented bone height was $5.21{\pm}0.94mm$ in 0.25 group and $6.92{\pm}1.19mm$ in 0.5 group. Statistically significant difference in augmented bone height was found in the comparison between the 0.25 group and 0.5 group at the time of surgery. There was a positive correlation between the length of the implant protruding into the maxillary sinus and the augmented bone height. After 6 months, mean reduction of augmented bone height was $0.50{\pm}0.34mm$ in 0.25 group and $0.41{\pm}0.30mm$ in 0.5group. There was no specific correlation between the reduction of augmented bone height and amount of grafted DBBM. Conclusion: Within the limit of this study, the amount of grafting materials and the protrusion length of implant into the maxillary sinus affect the amount of the augmented bone height.

• Journal of Trauma and Injury
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• 제33권1호
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• pp.18-22
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• 2020

Purpose: Damage control laparotomy has contributed to improved survival rates for severe abdominal injuries. A large part of severe abdominal injury occurs with a concomitant pelvic bone fracture. The safety and effectiveness of internal fixation of pelvic bone fracture(s) has not been established. The aim of the present study was to evaluate infection risk in the pelvic surgical site in patients who underwent emergent abdominal surgery. Methods: This single-center retrospective observational study was based on data collected from a prospectively maintained registry between January 2015 and June 2019. Patients who underwent laparotomy and pelvic internal fixation were included. Individuals <18 and ≥80 years of age, those with no microbiological investigations, and those who underwent one-stage abdominal surgery were excluded. Comprehensive statistical comparative analysis was not performed due to the small number of enrolled patients. Results: A total of six patients met the inclusion criteria, and the most common injury mechanism was anterior-posterior compression (67%). The average duration of open abdomen was 98 hours (range, 44-98), and the time interval between abdominal closure and pelvic surgery was 98 hours. One patient (16.7%) died due to multi-organ dysfunction syndrome. Micro-organisms were identified in the abdominal surgical site in five patients (83%), with no micro-organisms in pelvic surgical sites. There was no unplanned implant removal. Conclusions: Internal fixation of pelvic bone fracture(s) could be performed in the state of open abdomen, and the advantages of early fixation may countervail the risks for cross contamination.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 추계학술대회
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• pp.71-74
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• 1994

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권4호
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• pp.161-167
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• 2013

Objectives: The objective of this study is compare the rate of marginal bone resorption around hydroxyapatite-coated implants given different loading times in order to evaluate their stability. Materials and Methods: The study was conducted retrospectively for one year, targeting 41 patients whose treatment areas were the posterior maxilla and the mandible. Osstem TS III HA (Osstem Implant Co., Busan, Korea) and Zimmer TSV-HA (Zimmer Dental, Carlsbad, CA, USA), which employ the new hydroxyapatite coating technique, were used. The patients were divided into two groups - immediate and delayed loading - and the bone level at the time of loading commencement and after one year of loading was measured using periapical radiography. Differences between the groups were evaluated using Mann-Whitney (${\alpha}$=0.05). Results: For all patients as a single group, the survival rate of the implants was 100%, and the mean marginal bone loss was $0.26{\pm}0.59mm$. In comparison of the differences by loading, mean marginal bone loss of $0.32{\pm}0.69mm$ was recorded for the immediate loading group whereas the delayed loading group had mean marginal bone loss of $0.16{\pm}0.42mm$. However, the difference was not significant (P>0.05). Conclusion: Within the limited observation period of one year, predictable survival rates can be expected when using immediately loaded hydroxyapatite-coated implants.

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.61-70
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• 1996

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony inyowth and secondary long term fixation. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone stem interface. An accurate evaluation of interf'ace micromotion and stress/strain fields in the bone-implant system may be relevant for better understanding of clinical situations and improving THA design. Recently finite element method(FEM) was introduced in'orthopaedic research field due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional finite element model of proximal femur with $Multilock^{TM}$ stem of 1179 blick elements to analyse the micromotions and mechanical behaviors at the bone-stem inteface in early post-operative period for the load simulating single leg stance. The results indicates that the values of relative motion for this well fit stem were $150{\mu}m$ in maximum $82{\mu}m$ in minimum and the largest relative motion was developed in medial region of Proximal femur and in anterior-posterior direction. The motion in the proximal bone was much greater than in the distal bone and the stress pattern showed high stress concentration on the cortex near the tip of the stem. These findings indicate that the loading on the hip joint in the early postoperative situation before achieving bony ingrowth could produce large micromotion of $150{\mu}m$ and clinicaly non-cemented THA patient should not be allowed weight bearing strictly early in the postoperative period.