• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권2호
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• pp.177-184
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• 1991

저자등은, 치온부의 종괴를 주소로 내원한 10세 남아의 하악 우측 골체부에서, 동일한 부위에 함께 발생한 골내성 거내세포 육아종과 백아질 섬유종으로 진단된 증례로, 수술시 비교적 작은 크기의 백아질 섬유종은 골내성 거대세포 육아종과 비교적 경계가 잘 지워져 있었고, 두 병소의 발생기원이 서로 다른 점으로 미루어 이들 두 병소는 서로 독립하여 동일 부위에 발생한 것으로 사료되며, 임상적인 관점에서, 거대세포 육아종은 어린나이에 비교적 병소가 크고, 제1 제2 대구치의 치근 흡수 및 피판의 천공 소견을 보여 aggressive type으로 판단되어, 소파술과 전기 소작술을 이용하여 두 병소를 만족스럽게 치험하고, 1년이 지난 현재까지 수술에 따른 후유증이나 재발의 소견을 나타내지 않기에 문헌고찰과 함께 보고하는 바이다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권1호
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• pp.9-14
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• 2001

With the object of providing a temporary artificial periodonal ligament-like membrane around the dental implant, 10 Branemark type implants were coated with commercially available chitosan(Fluka Co., Buchs, Switzerland) which has a molecular weight of 70,000 and 80% deacetylation degree. Once this bioactive hydrophillic polymer(chitosan) contacts with blood or wound fluids, it becomes swollen and penetrates into the adjacent cancellous bone. Thus the interface between implant and surrounding bone is completely filled with chitosan. This tight junction in early healing phase enhances primary stability. The chitosan coated dental implants were implanted into the fresh patella bones from porcine knees, since the thickness of cortical bone is relatively even and their cancellous structure is homogenous. To test the shock absorbing effect, 1mm delta-rogette strain gage was installed behind the implant. The results showed 1. The principal strain peak value directed to the impact of coated implant was 0.064 0.018(p<0.05) and that of uncoated implant was 0.095(0.032 p<0.05). 2. The peak time delay of coated implant was 0.056sec(0.011 p<0.05) and that of uncoated implant was 0.024sec(0.009 p<0.05). It can be reasoned from this results that the chitosan coating has a shock absorbing effect comparable with a temporary artificial periodontal ligament.

• 대한치과보철학회지
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• 제44권5호
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• pp.584-593
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• 2006

Statement of problem : Dental implant which has been developed gradually through many experiments and clinical applications is presently used to various dental prosthetic treatments. To conduct a successful function of implant prosthesis in oral cavity for a long time, it is important that not only structure materials must have the biocompatibility, but also the prosthesis must be designed for the stress, which is occurred in occlusion, to scatter adequately of load support. Therefore, it is essential to give the consideration about the stress analysis of supporting tissues for higher successful rates. Purpose : Recently, many implant manufacturing company produce various taper design of root form implant, the fixture is often selected. However, the stress analysis of taper form fixture still requires more studies. Material and method : This study we make the element models that five implant fixture; Branemark system(Nobel Biocare, Gothenberg, Sweden), Camlog system(Altatec, Germany), Astra system(Astra Tech, Sweden), 3i system(Implant Innovations Inc, USA), Avana system(Osstem, Korea) were placed in the area of mandibular first premolar and prosthesis fabricated, which we compared with stress distribution using the three-dimension finite element analysis under two loading condition. Results : This study compares the aspect of stress distribution of each system with the standard of Von mises stress, among many resulted from finite element analysis so that this research gets the following results. 1. In all implant system, oblique loading of maximum Von mises stress of implant, alveolar bone and crown is higher than vertical loading of those. 2. Regardless of loading conditions and type of system, cortical bone which contacts with implant fixture top area has high stress, and cancellous bone has a little stress. under the vertical loading, maximum Von mises stress is more higher in order of Branemark, Camlog, Astra, 3i, Avana. under the horizontal loading, maximum Von mises is more higher in order of Camlog, Branemark, Astra, 3i, Avana.

• The Journal of Advanced Prosthodontics
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• 제6권5호
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• pp.361-371
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• 2014

PURPOSE. In case of large horizontal discrepancy of alveolar ridge due to severe resorption, cantilevered crown is usually an unavoidable treatment modality. The purpose of this study was to evaluate the clinical criteria for the placement of the aforementioned implant crown. MATERIALS AND METHODS. The mandible model with 2 mm thick cortical bone and cancellous bone was fabricated from CT cross-section image. An external connection type implant was installed and cantilevered crowns with increasing offset of 3, 4, 5, 6, and 7 mm were connected. Vertical load and $30^{\circ}$ oblique load of 300 N was applied and stress around bone and implant component was analyzed. A total of 14 cases were modeled and finite element analysis was performed using COSMOS Works (Solid works Inc, USA). RESULTS. As for the location of the vertical load, the maximum stress generated on the lingual side of the implant became larger according to the increase of offset distance. When the oblique load was applied at $30^{\circ}$, the maximum stress was generated on the buccal side and its magnitude gradually decreased as the distance of the offset load increased to 5 mm. After that point, the magnitude of implant component's stress increased gradually. CONCLUSION. The results of this study suggest that for the patient with atrophied alveolar ridge following the loss of molar teeth, von-Mises stress on implant components was the lowest under the $30^{\circ}$ oblique load at the 5 mm offset point. Further studies for the various crown height and numbers of occusal points are needed to generalize the conclusion of present study.

• 대한치과기공학회지
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• 제42권2호
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• pp.99-105
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• 2020

Purpose: A study analysed the stress distribution of abutment screw and supporting bone of fixture by the tightening torque force of the abutment screw within clinical treatment situation for the stability of the dental implant prosthesis. Methods: The finite element analysis was targeted to the mandibular molar crown model, and the implant was internal type 4.0 mm diameter, 10.0 mm length fixture and abutment screw and supporting bone. The occlusal surface was modeled in 4 cusps and loaded 100 N to the buccal cusps. The connection between the abutment and the fixture was achieved by combining three abutment tightening torque forces of 20, 25, and 30 Ncm. Results: The results showed that the maximum stress value of the supporting bone was found in the buccal cortical bone region of the fixture in all models. The von Mises stress value of each model showed 184.5 MPa at the 20 Ncm model, 195.3 MPa in the 25 Ncm model, and 216.5 MPa in the 30 Ncm model. The contact stress between the abutment and the abutment screw showed the stress value in the 20 Ncm model was 201.2 MPa, and the 245.5 MPa in the 25 Ncm model and 314.0 MPa in the 30 Ncm model. Conclusion: The increase of tightening force within the clinical range of the abutment screw of the implant dental prosthesis was found to have no problem with the stability of the supporting bone and the abutment screw.

• BMB Reports
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• 제45권4호
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• pp.227-232
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• 2012

In vertebrates, there are two variants of eukaryotic peptide elongation factor 1A (eEF1A; formerly eEF-$1{\alpha}$), eEF1A1 and eEF1A2, which have three well-conserved domains ($D_I$, $D_{II}$, and $D_{III}$). In neurons, eEF1A1 is the embryonic type, which is expressed during embryonic development as well as the first two postnatal weeks. In the present study, EGFP-tagged eEF1A1 truncates were expressed in cortical neurons isolated from rat embryo (E18-19). Live cell images of transfected neurons showed that $D_{III}$-containing EGFP-fusion proteins (EGFP-$D_{III}$, -$D_{II-III}$, -$D_{I-III}$) formed clusters that were confined within somatodendritic domains, while $D_{III}$-missing ones (EGFP-$D_I$, -$D_{II}$, -$D_{I-II}$) and control EGFP were homogeneously dispersed throughout the neuron including axons. In dendrites, EGFP-$D_{III}$ was targeted to the heads of spine- and filopodia-like protrusions, where it was colocalized with $SynGAP{\alpha}$, a postsynaptic marker. Our data indicate that $D_{III}$ of eEF1A1 mediates formation of clusters and localization to spines.

• Toxicological Research
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• 제20권3호
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• pp.241-250
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• 2004

We previously found that bisphenol A (BPA) caused neurotoxic behavioral alteration. Since disturbance of calcium homeostasis is an implicated contributor in the neurotoxic mechanism of environmental toxicants, we investigated whether BPA alters calcium homeostasis. Unlike other neurotoxic agents which cause increase of intracellular calcium level, BPA decreased $[Ca^{2+}]_i$ dose-dependently in PC12 cells and cortical neuronal cells regardless of the calcium existence in buffer. BPA at greater concentrations than 100 $\mu\textrm{M}$ reduced cell viability significantly in both types of cells. BPA also suppressed L-glutamate (L-type channel activator, 30 mM) and trifluoperazine (calmodulin antagonist, 30 $\mu\textrm{M}$)-induced increase of $[Ca^{2+}]_i$. BPA further lowered caffeine (RYR activator, 100 $\mu\textrm{M}$)-decreased $[Ca^{2+}]_i$, but did not alter dantrolene (RYR inhibitor, 100 $\mu\textrm{M}$), heparin (IP3 inhibitor, 200 units/ml) and xestospongin C (IP3 inhibitor, 5 $\mu\textrm{M}$)-decreased $[Ca^{2+}]_i$. Cell viability was not directly related to intracellular calcium change by bisphenol A that alternation of intracellular calcium may not be a direct causal factor of BPA-induced neuronal cell death.

• Clinics in Shoulder and Elbow
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• 제20권2호
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• pp.90-94
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• 2017

Background: Proximal humerus fracture is considered to be the third most common fracture for patients aged 65 years or older. Conservative treatment has been known to treat most of humerus fracture. However, fractures with severe displacement or dislocation may require surgical treatment. Intramedullary fibular allograft with a locking plate is frequently used in patients accompanying medial metaphyseal disruption. In this study, author intends to evaluate clinical and imaging results based on patients who underwent surgical treatment using fibular allograft with a locking plate. Methods: This study is conducted prospectively at Wonju Severance Christian Hospital, targeting patients who previously underwent surgical treatment using open reduction and intramedullary fibular allograft with a locking plate between 2011 and 2015. A total of 26 patients were evaluated on the following: postoperational clinical assessment measuring Constant score, American Shoulder and Elbow Society (ASES) score, and the Disabilities of the Arm, Shoulder and Hand (DASH) score. Postoperational imaging assessments are evaluated via measuring the neck-shaft angle. The study subject were Neer classification type 3, 4 proximal humerus fracture cases with disrupted medial hinge and having cortical comminution in the region of the surgical neck. Results: The average period of progression was 22.5 months, and the average age of patients was 72.6 years. At the final follow-up, the average Constant, average ASES, and average DASH scores were 80.1, 78.5, and 20.6 respectively. The average neck-shaft angle was $127.5^{\circ}$. Conclusions: In conclusion, fibular allograft augmentation with a locking plate showed satisfying results in both clinical and imaging studies.

• Applied Microscopy
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• 제47권2호
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• pp.63-69
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• 2017

Golgi staining has been modified and developed since Camillo Golgi introduced the black reaction in 1873. This study focuses on the commonly used Golgi staining methods and presents comprehensive data regarding three Golgi staining methods along with their strong and weak points. The Golgi-Cox method uses mercuric chloride for brain tissue impregnation and is a reliable technique for analyzing the complete dendritic tree of cortical neurons. However, specimens tend to shrink during the staining steps. Recent combination of the Golgi-Cox method and immunofluorescence provides additional options for neuroscientists. Rapid Golgi staining requires osmium tetroxide for the post-fixation process. It homogenously stains whole structures of neurons and provides their detailed anatomical morphology. This staining is influenced by the age of the specimen, temperature of the laboratory, and duration of each procedure. The Golgi-Kopsch method uses formaldehyde and glutaraldehyde instead of osmium tetroxide and can be used regardless of the age of the specimen and the duration after fixation. This method is suitable for research using human brain fixed for a long time or for specimens obtained from old-aged animals. Selecting a Golgi staining protocol that is appropriate for the specimen type and research purpose is important to achieve best results.

• 치과방사선
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• 제29권1호
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• pp.341-355
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• 1999

Squamous cell carcinoma is the most common type of oral cancer and odontogenic myxoma is relatively uncommon benign tumor of mesenchymal origin. There are, to our knowledge, no prior reports of simultaneously occurring squamous cell carcinoma and odontogenic myxoma of the jaw bones. In this case, at first, the plain films and computed tomograms revealed a large expansile multilocular radiolucent lesion on left mandible and marked expansion of cortical plate. In addition this radiograms revealed also infiltrative bony destruction of anterior and medial border of ascending ramus of left mandible and alveolar bone of left maxilla, floating teeth on left lower molar area and metastatic enlargement of left submandibular, jugular digastric and spinal accessory lymphnodes. Magnetic resonance imaging of this patient revealed infiltrative growth of tumor on alveolar bone of left maxilla, left retromolar fat pad. left masseter and left medial pterygoid muscle. Intraoral presurgical biopsy presented typical features of squamous cell carcinoma. After chemotherapy with radiation therapy during 6 months. this central lesion was diagnosed as odontogenic myxoma by the postsurgical biopsy. After 3 months, this patient presented multiple metastatic signs at lumbar spines, rib and liver. Consequently, our case is simultaneous occurrence of squamous cell carcinoma and odontogenic myxoma.