• Journal of Korean Neurosurgical Society
• /
• v.61 no.1
• /
• pp.114-119
• /
• 2018

Objective : The purpose of this study was to determine the feasibility of screw fixation in previously augmented vertebrae with bone cement. We also investigated the influence of cement distribution pattern on the surgical technique. Methods : Fourteen patients who required screw fixation at the level of the previous percutaneous vertebroplasty or balloon kyphoplasty were enrolled in this study. The indications for screw fixation in the previously augmented vertebrae with bone cement included delayed complications, such as cement dislodgement, cement leakage with neurologic deficits, and various degenerative spinal diseases, such as spondylolisthesis or foraminal stenosis. Clinical outcomes, including pain scale scores, cement distribution pattern, and procedure-related complications were assessed. Results : Three patients underwent posterior screw fixation in previously cemented vertebrae due to cement dislodgement or progressive kyphosis. Three patients required posterior screw fixation for cement leakage or displacement of fracture fragments with neurologic deficits. Eight patients underwent posterior screw fixation due to various degenerative spinal diseases. It was possible to insert screws in the previously augmented vertebrae regardless of the cement distribution pattern; however, screw insertion was more difficult and changed directions in the patients with cemented vertebrae exhibiting a solid pattern rather than a trabecular pattern. All patients showed significant improvements in pain compared with the preoperative levels, and no patient experienced neurologic deterioration as seen at the final follow-up. Conclusion : For patients with vertebrae previously augmented with bone cement, posterior screw fixation is not a contraindication, but is a feasible option.

• Advances in Traditional Medicine
• /
• v.6 no.2
• /
• pp.79-85
• /
• 2006

In order to study the effect of acupuncture stimulation on bone mineral density (BMD), using the ovariectomized (OVX) rat model, we assessed the degree of osteopenia by dual-energy X-ray absorptiometry, measured the level of locomotor activity using a metabolism measuring system, and performed histological studies of bone tissue. Twenty-four female Wistar rats (8 weeks old, 160 - 180 g)were divided into three groups. Rats in the OVX-A group underwent ovariectomy followed by acupuncture stimulation. The OVX rats in the Vehicle control group were not treated with acupuncture as a control. The rats in the control group received neither ovariectomy nor acupuncture. Acupuncture stimulation for 12 weeks in the OVX-A group inhibited the reduction in BMD of the femoral bones caused by ovariectomy. Moreover, in the two OVX groups, there was no clear difference in the level of locomotor activity between the active and resting phases prior to acupuncture stimulation in each rat, and the pattern of locomotor activity was irregular. After acupuncture stimulation of the OVX-A rats, the pattern of locomotor activity became diphasic with clear active and resting phases, as was observed in the Control group. On histological studies, the continuity of trabecular bone was maintained more favorably and bone mass was higher in the OVX-A group than in the vehicle control group. These results suggest that the increased locomotor activity that had been induced by acupuncture stimulation increased the BMD.

• Advances in biomechanics and applications
• /
• v.1 no.1
• /
• pp.1-14
• /
• 2014

In this paper, a simple and accurate finite element model coupled to quasi-brittle damage law able to describe the multiple cracks initiation and their progressive propagation is developed in order to predict the complete force-displacement curve and the fracture pattern of human proximal femur under quasi-static load. The motivation of this work was to propose a simple and practical FE model with a good compromise between complexity and accuracy of the simulation considering a limited number of model parameters that can predict proximal femur fracture more accurately and physically than the fracture criteria based models. Different damage laws for cortical and trabecular bone are proposed based on experimental results to describe the inelastic damage accumulation under the excessive load. When the damage parameter reaches its critical value inside an element of the mesh, its stiffness matrix is set to zero leading to the redistribution of the stress state in the vicinity of the fractured zone (crack initiation). Once a crack is initiated, the propagation direction is simulated by the propagation of the broken elements of the mesh. To illustrate the potential of the proposed approach, the left femur of a male (age 61) previously investigated by Keyak and Falkinstein, 2003 (Model B: male, age 61) was simulated till complete fracture under one-legged stance quasi-static load. The proposed finite element model leads to more realistic and precise results concerning the shape of the force-displacement curve (yielding and fracturing) and the profile of the fractured edge.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.5
• /
• pp.418-425
• /
• 2006

Purpose: This study was aimed at evaluating the histological changes of new bone and expression of osteopontin (OPN) after mandibular distraction osteogenesis. Materials and Methods: Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in eight adult dogs. Two animals were sacrificed at 7, 14, 28 and 56 days after completion of distraction, respectively. The distracted bones and contralateral non-distracted control bones were harvested and processed for histological and immunohistochemical examinations. Results: The new bone was arranged to tension direction after distraction osteogenesis. 7 days after distraction, numerous osteoblasts lining the immature trabecular bone and fibroblast-like cells in the fibrous intrezone were observed. 14 days after distraction, the new formed trabecular bones were thickened compared with 7 days after distraction. 28 days after distraction, the fibrous interzone was almost filled with newly calcified bone, and it was more hardened at 56 days after distraction. Increased OPN signals detected in the osteoblasts lining the trabecular bone and fibroblast-like cells in the fibrous interzone at 7 and 14 days after distraction. At 28 days after distraction, the OPN was weakly expressed in the osteoblasts, and it was not detected in all cellular components of distracted bone at 56 days later of distraction. Conclusions: After distraction osteogenesis, the distracted zone was completely calcified during the 56 days of consolidation period. In this study, the staining intensity of OPN increased in the osteoblasts and fibroblast-like cells at 7 and 14 days after distraction. The expression pattern of this protein shown here suggested that OPN play an important role in the osteogenesis during the early consolidation period.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.27 no.4
• /
• pp.359-370
• /
• 2011

To identify osseointegration of implants, dentists were performed the radiographic analysis. The fractal analysis methods using periapical radiographs before and after loading on implants was to evaluate whether or not significant. 30 patients who were placed implants in dental hospital of Wonkwang university were participated in this study. Total of 42 implants were analyzed. And, 14 males and 16 females aged from 22 to 73 participated in this study. The two morphologic and Fractal analysis of the one trabecular patterns in alveolar bone were done using periapical views. Two periapical views, after implant placement, and after 2 months of functional loading were analysed. The analysis was done by software, Image J(1.40s, National Institute of Health, Bethesda, USA). The data were statistically analyzed using one-way ANOVA(P<.05). Multiple comparison was done by the Tukey HSD test. The results of Fractal analysis and change in bone density around implants showed significantly different values, especially mandibles. However, in case of implants with failure, Fractal values decreased from 1.2865 to 1.1521 and 1.1135 to 1.0478.

• Journal of dental hygiene science
• /
• v.15 no.2
• /
• pp.98-105
• /
• 2015

We investigated the effects of a mutan (water-insoluble ${\alpha}$-glucans) isolated from Streptococcus mutans on the healing of bone defect in rat. Sprague-Dawley rats were divided into control (saline-treated), lipopolysaccharide (LPS)-treated, and mutan-treated groups (n=6 per group). Experimental bone defects were surgically created with round fissure bur at the buccal surface of the left mandibular. The control groups was administered with saline solution (0.1 ml/100 g), while the LPS and mutan group was given LPS and mutan (1 mg/kg body weight) three times weekly. After 4 weeks the rats were sacrificed, the healing of bone defect was assessed by bone mineral density (BMD) and micro-computed tomography (${\mu}CT$) examination. Percent bone volume (bone volume/tissue volume [BV/TV]), trabecular thickness (Tb.Th), and trabecular number (Tb.N) parameters of ${\mu}CT$ showed higher values in control group than LPS and mutan group. Bone surface/volume ratio (BS/BV), trabecular bone pattern factor (Tb.Pf), and structure model index parameters of ${\mu}CT$ showed higher values in LPS group than mutan group. BMD values of mutan treated-alveolar bones were significantly lower for than that of the LPS group. Therefore, we suggest that mutan, water-insoluble ${\alpha}$-glucans from S. mutans may be induce the induction of periodontal diseases.

• The Korean Journal of Cytopathology
• /
• v.1 no.1
• /
• pp.98-102
• /
• 1990

Hepatoblastoma (HB) is a rare embryonic malignant tumor of the liver. Most morphological studies on HB have limited to the histological characteristics and only 3 cases of HB have been described in the cytology literature. We present 2 cases of HB occurring in children aged 1 year and 3 years, respectively. The distinctive cytologic features of fine needle aspiration of HB were clusters of tumor cells showing acinar and trabecular pattern, smaller tumor cells with a high nuclear-cytopalsmic ratio and hyperchromatic nuclei having prominent nucleoli, and the presence of extramedullary hematopoiesis and osteoid material. These features were also found in the cell block and the biopsy specimen, and appeared very useful in the differentiation of HB from hepatocellular carcinoma.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.21 no.2
• /
• pp.504-509
• /
• 1994

Achondroplasia is characterized by undergrowth of long bones and cartilages and by low height. The name of this disease had been called classical chondrodystrophy, dyschondroplasia, chondrodystrophy and micromelia before Parrot reported the term of this disease as Achondroplasia. We are reporting in this paper on an 3-year and 4-month-old boy with achondroplasia. The dental findings are as follows: 1. Open bite and relatively mandibular prognathism were observed in the front teeth. 2. The size, number, shape, structure of the teeth were usual and the tongue was a little bigger than the normal. 3. The metacarpal bones were short and broadening. Mesial, distal border of the prox. phalanges were irregular and also trabecular pattern was abnormal in the hand-wrist P-A view. 4. According to lat. cephalometric analysis, the cranial basis was underdeveloped.

• Journal of Veterinary Clinics
• /
• v.34 no.6
• /
• pp.481-483
• /
• 2017

A 2-year-old neutered male Bengal cat presented with a 6-month history of weight loss and chronic vomiting. An abdominal ultrasound revealed increased thickness of the pylorus and ascending duodenum with concurrent enlargement of the mesenteric lymph nodes. Histologically, branching and anastomosing trabecular pattern of dense collagen was the characteristic feature, and large populations of spindle cells were also observed. These large spindle-shaped cells were positive for smooth muscle actin and vimentin on immunohistochemical examination. Based on these findings, the cat was diagnosed with feline gastrointestinal eosinophilic slcerosing fibroplasia (FGESF), and immunosuppressive therapy was initiated immediately. Unfortunately, the cat's condition deteriorated despite treatment; the cat died 56 days after initiation of therapy. This is the first report of FGESF in South Korea.

• The Korean Journal of Cytopathology
• /
• v.19 no.1
• /
• pp.9-15
• /
• 2008

The major categories of neuroendocrine tumors of lung are typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma. The histologic classification criteria of neuroendocrine tumors are well documented in the "WHO Classification of Tumors" based on mitotic figures and necrosis. Cytologic characteristics of neuroendocrine tumors are trabecular, acinar, and solid arrangement of tumor cells and occasional rosette formation. Nuclear chromatin patterns are characteristically described as "salt and pepper chromatin pattern". Many of cytologic classifications documented in the literature are before the "WHO Classification". In this review, the cytologic features of pulmonary neuroendocrine tumors are documented according to the WHO classification, and recent concepts of neuroendocrine tumors of lung are discussed.