• Journal of Periodontal and Implant Science
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• 제34권2호
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• pp.303-315
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• 2004

The success and failure of dental implants depends on various factors such as patient's systemic status, quantity and quality of surrounding bone, presence or absence of marginal infection and mechanical loading condition. The measurement of crestal bone changes around the implants is implemental to evaluate the success and long-term prognosis of the implant. This study was to evaluate the cumulative survival rate of the implants which had been placed in the Department of Periodontics, Chonnam National University Hospital between 1992 and 2003, and to observe the crestal bone loss around the implants which had at least 2 consecutive periapical radiographs after connecting the transmucosal abutment. The radiographs were scanned and digitalized, and the crestal bone levels on the mesial and distal surface of implants were measured using Image analyzer (Image Pro Plus, Media Cybernetics, USA), immediately after implant placement, at 2nd surgery, and 3 months, 6 months, 1 year, and every year thereafter. Any bone loss was not observed during the period between the 1stand 2nd surgery, and the bone loss was 0.86 ${\pm}$ 0.92 mm for the first year of loading after connecting the transmucosal abutment. After 1 year of loading, annual bone loss was 0.1 ${\pm}$ 0.27 mm, and total bone loss was 0.90 ${\pm}$ 0.80 mm (during the average follow-up periods of 22.5 ${\pm}$ 25.6 Mos), The implant, with smooth surface, in the mandible, and with the fixed bridge prosthesis showed greater bone loss, compared to those, with the rough surface, in the maxilla and with single crown. In systemically diseased patients (including DM or osteoporosis), the greater bone loss was observed. The cumulative survival rate among 432 implants was 94.10% for 7 years. Among 15 failed implants, 9 implants were removed due to mobility from disintegration of bone-implant interface. From this results, crestal bone loss around the implants were greatest during 1 year after transmucosal abutment connection, and various factors could affect peri-implant bone loss. To prevent and predict the bone loss around the implants and improve the prognosis, further comprehensive maintenance and follow-up schedules are required.

• 대한치과보철학회지
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• 제43권2호
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• pp.248-257
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• 2005

Statement of problem. Cortical bone plays an important role in the primary implant stability, which is essential to immediate/early loading. However, immediate load-bearing capacity and primary implant stability according to the change of the cortical bone thickness have not been reported. Purpose. The objectives of this study were (1) to measure the immediate load-bearing capacity of implant and primary implant stability according to the change of cortical bone thickness, and (2) to evaluate the correlation between them. Material and methods.48, screw-shaped implants (3.75 mm$\times$7 mm) were placed into bovine rib bone blocks with different upper cortical bone thickness (0-2.5 mm) and resonance frequency (RF) values were measured subsequently. After fastening of healing abutment. implants were subjected to a compressive load until tolerated micromotion threshold known for the osseointegration and load values at threshold were recorded. Thereafter, RF measurement after loading, CT taking and image analysis were performed serially to evaluate the cortical bone quality and quantity. Immediate load-bearing capacity and RF values were analyzed statistically with ANOVA and post-hoc method at 95% confidence level (P<0.05). Regression analysis and correlation test were also performed. Results. Existence and increase of cortical bone thickness increased the immediate load-bearing capacity and RF value (P<0.05) With the result of regression analysis, all parameter's of cortical bone thickness to immediate load-bearing capacity and resonance frequency showed significant positive values (P<0.0001). A significant high correlation was observed between the cortical bone thickness and immediate load-beating capacity (r=0.706, P<0.0001), between the cortical bone thickness and resonance frequency (r=0.753, P<0.0001) and between the immediate load-bearing capacity and resonance frequency (r=0.755, P<0.0001). Conclusion. In summary, cortical bone thickness change affected the immediate load-baring capacity and the RF value. Although RF analysis (RFA) is based on the measurement of implant/bone interfacial stiffness, when the implant is inserted stably, RFA is also considered to reflect implant/bone interfacial strength of immediately after placement from high correlation with the immediate load-baring capacity. RFA and measuring the cortical bone thickness with X-ray before and during surgery could be an effective diagnosis tool for the success of immediate loading of implant.

• 대한방사성의약품학회지
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• 제5권1호
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• pp.48-53
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• 2019

A bone metastasis is an important factor for prognosis and treatment of breast or prostate cancer patients. [$^{18}F$]Sodium fluoride ([$^{18}F$]NaF) is a PET radiopharmaceutical that can detect bone metastasis. Conventional [$^{18}F$]NaF production process included radioactive metal impurities because the product was prepared by adding saline after beam irradiation to $[^{18}O]H_2O$. In this study, we apply the method of removing radionuclidic impurities. To meet the criteria prescribed by GMP in quality control, we designed the custom-made [$^{18}F$]NaF automatic module. The mean radiochemical yield was $82.1{\pm}4.4%$ (n = 32) productions for 3 years) and the total preparation time was 4 min. The final produced [$^{18}F$]NaF solution meets the USP criteria for quality control. Thus, this fully automated system is validated for clinical use.

• 대한의용생체공학회:의공학회지
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• 제30권2호
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• pp.135-141
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• 2009

Purpose: The aim of present study is to evaluate a possibility of clinical application for the effect of low intensity ultrasound stimulation (LIUS) in mechanical characteristics of bone on osteoporotic fractures prevention. Materials and Methods: Eight virgin ICR mice (14 weeks old, approximate weight 25g) were ovariectomized (OVX) to induce osteoporosis. The right hind limbs were then stimulated with LIDS (US Group), whereas left hind limbs were not stimulated (CON Group). Both hind limbs of all mice were scanned by in-vivo micro-CT to acquire two-dimensional (2D) images at 0 week before stimulation and 3 weeks and 6 weeks after stimulation. Three-dimensional (3D) finite element (FE) models generated by scanned 2D images were used to determine quantitatively the effect of LIUS on strength related to bone structure. Additionally, distributions of Hounsfield units and elastic moduli, which are related to the bone quality, for the bones in the US and CON groups were determined to analyze quantitatively a degree of improvement of bone qualities achieved by LIUS. Results: The result of FE analysis showed that the structural strength in US Group was significantly increased over time (p<0.05), while that in CON Group was statistically constant over time (p>0.05). High values of Hounsfield units obtained from voxels on micro-CT images and high values of elastic moduli converted from the Hounsfield units were dominantly appeared in US Group compared with those in CON Group. Conclusion: These finding indicated that LIUS would improve the mechanical characteristics of osteoporotic bone via the effects of bone structure (bone strength) and quality (Hounsfield unit and elastic modulus). Therefore, the LIUS may decrease effectively the risk of osteoporotic fracture in clinics.

• Journal of Periodontal and Implant Science
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• 제46권5호
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• pp.303-319
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• 2016

Purpose: The purpose of this animal study was to perform a 3-dimensional micro-computed tomography (micro-CT) analysis in order to investigate the influence of root surface distance to the alveolar bone and the periodontal ligament on periodontal wound healing after a guided tissue regeneration (GTR) procedure. Methods: Three adult Sus scrofa domesticus specimens were used. The study sample included 6 teeth, corresponding to 2 third mandibular incisors from each animal. After coronectomy, a circumferential bone defect was created in each tooth by means of calibrated piezoelectric inserts. The experimental defects had depths of 3 mm, 5 mm, 7 mm, 9 mm, and 11 mm, with a constant width of 2 mm. One tooth with no defect was used as a control. The defects were covered with a bioresorbable membrane and protected with a flap. After 6 months, the animals were euthanised and tissue blocks were harvested and preserved for micro-CT analysis. Results: New alveolar bone was consistently present in all experimental defects. Signs of root resorption were observed in all samples, with the extent of resorption directly correlated to the vertical extent of the defect; the medial third of the root was the most commonly affected area. Signs of ankylosis were recorded in the defects that were 3 mm and 7 mm in depth. Density and other indicators of bone quality decreased with increasing defect depth. Conclusions: After a GTR procedure, the periodontal ligament and the alveolar bone appeared to compete in periodontal wound healing. Moreover, the observed decrease in bone quality indicators suggests that intrabony defects beyond a critical size cannot be regenerated. This finding may be relevant for the clinical application of periodontal regeneration, since it implies that GTR has a dimensional limit.

• 대한골관절종양학회지
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• 제17권1호
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• pp.1-10
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• 2011

악성 골종양의 치료의 주된 목적은 장기 생존기간을 연장 및 삶의 질적 개선이나, 소아의 경우 골격 성장이 지속되어 종양 치료 후 성장 완료 시 나타나는 하지 부동(leg length discrepancy)이 치료에 있어 중요한 문제 중 하나이다. 성장기 소아의 하지 부동을 치료하기 위해서는 먼저 소아의 정상적인 성장에 대한 정확한 이해가 필요하며, 성장 과정에서의 하지 부동의 정도를 예측하는 것은 이에 대한 수술적 치료의 시기 및 방법의 선택에 있어 필수적이다. 또한 이러한 성장 예측 방법들을 적절히 사용하기 위해서는 지속적인 추시 관찰이 필수적이므로 환아의 부모와의 긴밀한 협조 또한 중요할 것으로 생각된다.

• The Journal of Advanced Prosthodontics
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• 제3권2호
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• pp.96-100
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• 2011

An 18-year-old male presented severe hypodontia due to hypohidrotic ectodermal dysplasia was treated with Le Fort I maxillary osteotomy with simultaneous sinus floor augmentation using the mixture of cortical autogenous bone graft harvested from iliac crest and organic Bio-Oss to position the maxilla in a right occlusal plane with respect to the mandible, and to construct adequate bone volume at posterior maxilla allowing proper implant placement. Due to the poor bone quality at other sites, ridge augmentation with onlay graft was done to construct adequate bone volume allowing proper implant placement, using tissue harvested from the iliac bone. Seven implants were placed in the maxilla and 7 implants were inserted in the mandible and screw-retained metal ceramic FPDs were fabricated. The two year follow up data showed that dental implants should be considered as a good treatment modality for patients with ectodermal dysplasia.

• 대한족부족관절학회지
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• 제27권2호
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• pp.43-48
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• 2023

The incidence of osteoporotic ankle fractures is increasing as the population ages. These fractures are becoming more common in clinical practice and require careful management because of the higher likelihood of developing complications than typical ankle fractures. The introduction of a method for measuring the ankle joint bone mineral density is a valuable tool for assessing the bone quality of the ankle joint. By evaluating the bone mineral density, healthcare professionals can better understand the extent of osteoporosis and the overall strength of the ankle joint. This information is crucial for determining the appropriate treatment for individual fractures. Several factors must be considered when deciding on the treatment for osteoporotic ankle fractures. These include the ankle joint bone mineral density, skin condition, any comorbidities the patient may have, and the patient's functional demands. Taking these factors into consideration allows healthcare providers to tailor the treatment plan to the specific needs and the circumstances of each patient. By applying the appropriate treatment, it is expected that the complications associated with osteoporotic ankle fractures can be minimized, and the prognosis for patients can be improved.

• 한국식생활문화학회지
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• 제21권6호
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• pp.596-605
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• 2006

This study was conducted to investigate factors affecting gone density of university students in Seoul area. Data for food habits, exercise and health-related behaviors were obtained by self administered questionnaires. BQI(bone quality index) of the subjects was measured by an Quantitative Ultrasound(QUS). The results are summarized as follows: The average hight, weight BMI and osteopenia percentage of the male and female student were 173.3cm, 68.6kg, 22.7 and 24.2%; 161.4cm, 54.4kg, 20.9 and 55.5%, respectively. The BQI and Z-score of the subjects were 99.6, -0.3 in male student group, and 82.7, -1.1 in female student group, respectively. Height, weight, fat weight, fat mass and BMI were positively related with BQI in female group. BQI was positively affected by breakfast and frequence exercise in male student group. In female student group, frequency exercise was positively related with BQI. The result of this study revealed that the desirable food habits, dietary behaviors and health-related lifestyles may have a beneficial effect on bone density. They should have practically and systematically organized nutritional education on optimum body weight, good eating habits, weight bearing exercise for higher bone density level.

• 한국식생활문화학회지
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• 제22권6호
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• pp.841-847
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• 2007

This study was conducted to investigate on bone density and nutrient intake of university students in Seoul area. Nutrient intake data were obtained by using the 24-hour recall method to evaluate the usual diet of the subjects. BQI(bone quality index) of the subjects was measured by an Quantitative Ultrasound (QUS). The results are summarized as follows: The average height, weight, BMI of the male and female student were 173.3 cm, 68.5 kg, 22.7; 161.4 cm, 54.2 kg, 20.8, respectively. The BQI and Z-score of the subjects were 99.50, -0.69 in male student group, and 82.6, -1.15 in female student group, respectively. Normal, osteopenia and osteoporosis percentage by bone status were 73.8%, 24.9%, 1.3% in male student group, and 39.8%, 57.6%, 2.6% in female student group, respectively. Energy intake of male and female group were 71.7%, 79.1% of EER(estimated energy requirement) respectively. Fiber, Ca, Vit $B_2$, niacin, folic acid, Vit C intake were less than RI(recommended intake) and protein, phosphorus intake were higher than RI in subjects. Nutrient intake were not significantly related with BQI in male and female groups generally.