• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권1호
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• pp.57-61
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• 2021

Immediate implant placement (IIP) in fresh extraction sockets exhibits similar survival and success rates to delayed implant placement in healed sockets. Several advantages of IIP involve shortened total treatment time, reduction of the number of invasive surgeries, and subsequent reduction of patient discomfort due to lack of additional surgeries. The major shortcomings in IIP, however, include the inability to obtain early bony support, presence of a gap between the extraction socket and fixture, and the inability to cover the fixture with soft tissue, leading to increased risk of infection and implant loss. When IIP is performed, atraumatic or minimally traumatic extractions, conservation of the septal bone in molars, minimal flap elevation or flapless surgery, bone grafting the gap between the fixture and the extraction socket, and coverage with soft tissue or a membrane must be considered.

• 대한치과교정학회지
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• 제25권6호
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• pp.715-722
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• 1995

Orthodontic tooth movement in response to orthodontic force results from actions of osteoclasts and osteeoblasts in the cell level. Convincing evidence has now been provided to support the view that osteoclasts are derived from mononuclear cells that originate in the bone marrow or other hematopoietic organs and they migrate to the bones via vascular routes. Nitric oxide(NO), which accounts for the biological properties of endothelium-derived relaxing factor(EDRF), is the endogenous stimulator of soluble guanylate cylase. The discovery of the formation of nitric oxide(NO) from L-arginine in mammalian tissues and its biological roles has, in the last 7 years, thrown new light onto many areas of research. Data from experiments in vitro showed that N-metyl-L-arginine(L-NMA) and L-nitro-L- arginine(L-NAME) are competitive inhibitors of nitric oxide synthase. This study suggest that the multinucleated cells in our culture have characteristics of osteoclasts and that the potential bone cell activity of nitric oxide in vitro may be mediated in part by stimulation of marrow mononuclear cells to form osteoclast-like cells. Bone marrow cells were obtaineed from tibia of 19-days old chick embryo. After sacrifice, tibia was quickly dissected and the bone were then split to expose the medullary bone. The cells were attached for 4 hours and the nonadherent cells were collected. Marrow cells weere cultured in 96-well plate in medium 199. To examine the number of TRAP-positive multinucleated cells(MNCs), $10^{-8}\;M\;Vit=D_3$ and various concentration of L-NMA and L-NAME weere added at the beginning of cultures and with each medium change. After 7 days of culture. tartrate-resistant acid phosphatase(TRAP) staining was performed for microscopic evaluation. Cells haying more than three nuclei per cell were counted as MNCs. The obsrved results were as follows;1. 1,25-dihydroxyvitamine $D_3$ stimulated the osteoclast-like multinucleated cells in cultures of chick embryo bone marrow. 2. Nitric oxide synthase inhibitors(NOSI ; N-NMA, N-NAME) stimulated the osteoclast-like cells in cultures of chick embry bone marrow. 3. 1,25-dihydroxyvitamine$D_3$ and nitric oxide synthase inhibitors did not appear to have additive effect on the generation of TRAP-positive MNCs. These results suggest that nitric oxide synthase inhibitors may stimulate the osteoclast-like multinucleated cell formation and fusion in cultures of chick bone marrow.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권6호
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• pp.397-402
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• 2009

The purpose of this study is to investigate the effects of alendronate and pamidronate on proliferation and the alkaline phosphatase activity of human bone marrow derived mesenchymal stem cells and to relate the results with bisphosphonate related osteonecrosis of the jaw(BRONJ). With the consent of patients with no systemic disease and undergoing iliac bone graft, cancellous bone was collected to obtain human bone marrow derived mesenchymal stem cells through cell culture. 96 well plate were prepared with a concentration of $10^4$cell/ well. Alendronate and pamidronate were added to each well with the concentration of $10^{-6}M$, $10^{-8}M$ and $10^{-10}M$, respectively. Then proliferation capacity of each well was evaluated with the cell counting kit. 24 well plates were prepared with a concentration of $10^5$cell/ml/well and with the bone supplement, alendronate and pamidronate were added with the concentration of $10^{-6}M$, $10^{-8}M$ and $10^{-10}M$, respectively on each plate. The plates were cultured for either 24 or 72 hours. Then the cells were sonicated to measure the alkaline phosphatase activity and protein assay was done to standardize the data for analysis. As the concentration of alendronate or pamidronate added to the culture increased, the proliferation capacity of the cells decreased. However, no statistical significance was found between the group with $10^{-10}M$ of bisphophonate and the control group. Pamidronate was not capable of increasing the alkaline phosphatase activity in all trials. However, alkaline phosphatase activity increased with 24 hours of $10^{-8}M$ of alendronate treatment and with 48 hours of $10^{-10}M$ of alendronate treatment. Cell toxicity increased as the bisphosphonate concentration increased. This seems to be associated with the long half life of bisphosphonate, resulting in high concentration of bisphosphonate in the jaw and thus displaying delayed healing after surgical procedures. Alendronate has shown to increase the alkaline phophatase activity of human bone marrow derived mesenchymal stem cells. However, this data is insufficient to conclude that alendronate facilitates the differentiation of human bone marrow derived mesenchymal stem cells. Further studies on DNA level and animal studies are required to support these results.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.428-433
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• 2004

Sinus floor augmentation has been proven an effective treatment procedure to increase bone volume in the posterior edentulous maxilla. Autogenous bone considered to be the best material for reconstructive bone surgery and has been successfully used as a graft material to augment posterior maxilla. However, the collection of autogenous bone required extra risks for morbidity and complaints. So, various bone graft materials included ${\beta}$-tricalcium phosphate(${\beta}$-TCP) has been introduced for replacing the autogenous bone. The objective of this clinical study was to determine the predictability of endosseous implant placed in a maxillary sinus with ${\beta}$-TCP grafting. We performed sinus elevation with ${\beta}$-TCP to install the implant in the 10 maxillary cases. The prosthetic procedure was performed 6-9 months after. The implant-prosthetics was checked about 1 year. We checked the implant and measured the maximum bite force to evaluate the function of the implant. There was not observed the specific problem and complication in dental implant and maxillary sinus in the grafted materials. The maximum bite force was 558N in case of natural tooth, 365N in implant without grafting, 318N in implant with ${\beta}$-TCP grafting. There was no significant difference between with and without sinus grafting on maximum bite force(p>0.05). As though the long term check-up is needed, the grafting of ${\beta}$-TCP as a osteoconductive materials can expand the volume and induce dense new bone formation in maxillary sinus. So, this short-term results support that ${\beta}$-TCP can be a suitable material for sinus augmentation.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권2호
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• pp.142-149
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• 2008

The purpose of this study was to evaluate histomorphometrically a toothash - plaster of Paris mixture associated with collagen membrane ($Bio-Gide^{(R)}$), regarding new bone formation in the peri-implantitis defects in dogs. Three mandibular molars were removed from 1-year-old mongrel dogs. After 2 months of healing, 2 titanium implants with sandblasted with large grit and acid etched (SLA) surface were installed in each side of the mandible. Experimental peri-implantitis was induced with ligatures after successful osseointegration. Ligatures were removed after identification of bone defect beneath the level of 5th thread of fixture on radiographic image. The mucoperiosteal flaps were elevated and the contaminated fixtures were treated with chlorhexidine and saline. The bone defects were assigned to one of the following treatments: no guided bone regeneration (GBR) procedure (group 1), GBR with Bio-$Oss^{(R)}$ and Bio-$Gide^{(R)}$ (group 2), or GBR with toothash - plaster of Paris mixture (TPM) and Bio-$Gide^{(R)}$ (group 3). The dogs were sacrificed after 8 or 16 months. The mean percentages of new bone formation within the limits of the 5 most coronal threads were $17.83{\pm}10.69$ (8 weeks) and $20.13{\pm}13.65$ (16 weeks) in group 1, $34.25{\pm}13.32$ (8 weeks) and $36.33{\pm}14.21$ (16 weeks) in group 2, and $46.33{\pm}18.39$ (8 weeks) and $48.00{\pm}17.78$ (16 weeks) in group 3, respectively. The present study confirmed statistically considerable new bone formation within the threads in group 3 compared with group 1 at 8 and 16 weeks (P<0.05). Although, data analysis did not reveal significant differences between group 2 and 3, the latter showed better results during the period of 8 or 16 weeks. Our findings support the effectiveness of TPM as a GBR material in the treatment of peri-implantitis bone defect.

• Advances in nano research
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• 제13권6호
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• pp.575-585
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• 2022

Due to its biofilm formation and colonization of the osteocyte-lacuno canalicular network (OLCN), Staphylococcus aureus (S.aureus) implant-associated bone infection (SIABI) is difficult to cure thoroughly, and may occur recurrently subsequently after a long period dormant. It is essential to explore an alternative therapeutic strategy that can eradicate the pathogens in the infected foci. To address this, the polymethylmethacrylate (PMMA) bone cement and Fe3O4 nanoparticles compound cylinder were developed as implants based on their size and mechanical properties for the alternative magnetic field (AMF) induced thermal ablation, The PMMA mixed with optimized 2% Fe₃O₄ nanoparticles showed an excellent antibacterial efficacy in vitro. It was evaluated by the CFU, CT scan and histopathological staining on a rabbit 1-stage transtibial screw model. The results showed that on week 7, the CFU of infected soft tissue and implants, and the white blood cells (WBCs) of the PMMA+2% Fe₃O₄+AMF group decreased significantly from their controls (p<0.05). PMMA+2% Fe₃O₄+AMF group did not observe bone resorption, periosteal reaction, and infectious reactive bone formation by CT images. Further histopathological H&E and Gram Staining confirmed there was no obvious inflammatory cell infiltration, neither pathogens residue nor noticeably burn damage around the infected screw channel in the PMMA+2% Fe₃O₄+AMF group. Further investigation of nanoparticle distributions in bone marrow medullary and vital organs of heart, liver, spleen, lung, and kidney. There were no significantly extra Fe₃O₄ nanoparticles were observed in the medullary cavity and all vital organs either. In the current study, PMMA+2% Fe₃O₄+AMF shows promising therapeutic potential for SIABI by providing excellent mechanical support, and promising efficacy of eradicating the residual pathogenic bacteria in bone infected lesions.

• 대한영양사협회학술지
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• 제4권1호
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• pp.65-75
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• 1998

Recently, the number of patients who received Bone Marrow Transplantation(BMT) has been increased dramatically and the diseases for which BMT if efficacious are increasing. Adequate nutritional card for BMT patients is crucial for the success of BMT because nutritional deficiency could provoke deteriorative effects. However, little is known about nutritional status among BMT patients in Korea. This study was conducted to assess oral and parenteral intake of BMT patients and compare the change of nutritional status before and after BMT. Twenty-two BMT patients who were admitted to the Severance hospital from December in 1995 to September in 1997 participated in the study. Total calorie requirements were calculated for each patients individually and nutritional support for each patients consisted of oral and parenteral feeding. To assess oral intake of BMT patients, each patients recorded the amount of food they have eaten from 6 days before BMT to 28 days after BMT. The medical records of each patients were used to assess parenteral intake. To compare the nutritional status before and after BMT, the results of anthropometric and biochemical test from 14 days before BMT to 28 days after BMT were used. At the time of admission, the patients were in allowable nutritional status and their total calorie intake was 93% of total calorie requirement. When the preparative regimen for BMT was started, the patients' oral intake was dramatically decreased below 400kcal/day. Even though their oral intake was increased after BMT, their oral intake at the 4th week after BMT was only 752kcal/d, which is only 35.8% of total calorie requirement. The patients' mean oral intake during BMT period (from 6 days before BMT to 28 days after BMT) was only 439kcal/d. Although Total Parenteral Nutrition(TPN) was added when the preparative regimen was started, the patients' mean total caloric intake during BMT period was 111% of basal energy expenditure and 83% of total calorie requirement. The mean total protein intake was only 58% of total protein requirement. In the comparison of nutritional status between pretransplant phase and posttransplant phase in BMT patients, their body weight and serum albumin level were significantly decreased(p<0.001). These results show inadequacies in nutritional intake among BMT patients, and indicate the need of TPN during BMT period.

• The Journal of Advanced Prosthodontics
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• 제7권3호
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• pp.240-248
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• 2015

PURPOSE. To explore whether there is matching relation between the length and the tilting angle of terminal implants in the All-on-Four protocol by studying the effects of different implant configurations on stress distributions of implant, bone, and framework. MATERIALS AND METHODS. Four implants were employed to support a full-arch fixed prosthesis and five three-dimensional finite element models were established with CT images, based on the length (S and L) and distal tilt angle ($0^{\circ}$, $30^{\circ}$ and $45^{\circ}$) of terminal implants for an edentulous mandible, which named: Tilt0-S, Tilt30-S, Tilt30-L, Tilt45-S and Tilt45-L. An oblique 240 N was loaded at second molar. The von Mises Stresses were analyzed. The implants were consecutively named #1 to #4 from the loading point. RESULTS. 1) Tilt0-S had the greatest stress on the implants, with the other groups exhibiting variable reductions; the four implants of Tilt45-L demonstrated the greatest reduction in stress. 2) Tilt0-S had the greatest stress at bone around #1 implant neck, and Tilt45-L exhibited the least stress, which was a 36.3% reduction compared to Tilt0-S. 3) The greatest stress in the framework was found on the cantilevers distal to #1 implant. Tilt45-S exhibited the least stress. CONCLUSION. Matching different length and tilting angle of the terminal implants led to variable stress reductions on implants, bone and the superstructure. By optimizing implant configuration, the reduction of stress on implants and surrounding bone could be maximized. Under the present condition, Tilt45-L was the preferred configuration. Further clinical testings are required.

• Journal of Nutrition and Health
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• 제29권9호
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• pp.991-1002
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• 1996

The objectives of this study were to obtain normative data for 45 mother-daughter pairs on spine, femur(neck, ward's triangle, trochanter) and total body BMD (bone mineral density) measured by dual energy X-ray absorptiometry, anthropometric measurement, body composition, biochemical markers, nutrient intakes and energy expenditure, to determin the interrelations of these factors within each group, to measure familial resemblance for each variable. We observed significantly positive correlations between height, weight, head, hip and calf circumferences, tricep, femur and calf skinfold thickness, total lean body mass(=weight-total fat body mass-bone mineral content), protein and fat intakes, Ca index, serum total protein and albumin of monter-daughter pairs(p<.05-p<.001). Among mothers, age, osteocalcin, higher, weight, Ca and energy intakes were predictors of BMDs. Among daughters, weight and energy intake were predictors of BMDs. The BMD in lumbar spine(r=.48, p<.01), femoral neck(r=.38, p<.05), ward's triangle(r=.36, p<.05) of the mothers were significantly correlated with those of the daughters, after adjustment for mother's age, hight, weight, osteocalcin, Ca and energy intakes and daughter's weight, energy intake. In regression analyses, mother's BMD also were positively associated with daughter's BMD in lumbar spine, femoral neck, ward's triangle. Our findings support that mothers with low BMD tended to have daughters with low BMD. In the age groups studied, as well genetic factors as environmental factors may have an important role in determining BMD. This study suggests that women may successfully enhance their genetically determined BMD through adequate nutrient intakes and weight bearing exercise.

• Archives of Plastic Surgery
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• 제40권4호
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• pp.335-340
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• 2013

Background In patients with medial orbital wall fracture, predicting the correlation between the degree of enophthalmos and the extent of fracture is essential for deciding on surgical treatment. We conducted this retrospective study to identify the correlation between the two parameters. Methods We quantitatively analyzed the correlation between the area of the bone defect and the degree of enophthalmos on computed tomography scans in 81 patients with medial orbital wall fracture who had been left untreated for more than six months. Results There was a significant linear positive correlation between the area of the medial orbital wall fracture and the degree of enophthalmos with a formula of E=0.705A+0.061 (E, the degree of enophthalmos; A, the area of bone defect) (Pearson's correlation coefficient, 0.812) (P<0.05). In addition, that there were no cases in which the degree of enophthalmos was greater than 2 mm when the area of the medial orbital wall fracture was smaller than $1.90cm^2$. Conclusions Our results indicate not only that 2 mm of enophthalmos corresponds to a bone defect area of approximately $2.75cm^2$ in patients with medial orbital wall fracture but also that the degree of enophthalmos could be quantitatively predicted based on the area of the bone defect even more than six months after trauma.