• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.27-32
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• 2004

In this study, method of PMMA injection is suggested for vertebroplasty in patients with osteoporotic compression fracture. The finite element analysis is used to investigate the vertebroplasty quantitatively. In order to improve previous works with simplified geometry of vertebral body more exact geometry has been constructed from CT image data with 1m thickness. An ideal method of PMMA delivery, with respect to location and amount of injectate, into vertebral body has been suggested based on evaluation of the insert positions and the insert shapes of injected PMMA. It is shown that vertebral body can be compensated most efficiently when PVIMA is highly concentrated on the top-front of trabecular bone of compressed vertebra.

• Journal of Yeungnam Medical Science
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• v.8 no.1
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• pp.198-205
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• 1991

We obtained successful functional and esthetic results by grafting of iliac marrow-cancellous bone in 2 cases of alveolar-palatal cleft patients. Bone graft of alveolar-palatal clefts provide bony support to adjacent teeth of cleft area, prevented from relapse of orthodontic arch expansion, closure of oroantral fistula and improvement of speech problem. 1. In one case, extraction of upper right central incisor that was little bone support, alignment of rotated teeth and expansion of collapsed arch segment were done with pre-ortodontic treatment. The other case, Bone grafting was done after removal of prosthesis with no preorthodontic treatment. 2. After mucoperiosteal incision in cleft area. The mucosal flap of labial area, palate and nose were separation and the raised nasal mucosa was sutured for closure of oroantral fistula. Then, the iliac marrow-cancellous bones were grafted to cleft site. 3. After 6 months of operation, we had seen the new bone deposition to cleft site in dental radiography and prosthetic treatments of missing teeth were done.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.142-146
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• 2004

Bizzare parosteal osteochondromatous proliferation is a rare lesion, tends to frequently recur. It was first described in 1983, when Nora and his colleagues reported 35 examples of a proliferative lesion involving small bones of the hand and the feet. It was regarded as occurring only in the small bones of the hand and the feet initially, but from then on, other authors have been reported cases including those involving long bones, skull and maxilla. We experienced a case of bizzare parosteal osteochondromatous proliferation which affects the humeral shaft in a 14-year-old male patient. Radiographs showed calcified mass measuring $4{\times}3$ cm in size and attached to the underlying cortex, which had a broad stalk base. Histologically, it showed hypercellular cartilage maturation to the trabecular bone and plump amount of fibrous stroma in the spaces around the bony trabeculae. Bizzare parosteal osteochondromatous proliferation is a relatively rare lesion, but has a recurrent behavior and histologically tends to be mistaken for malignancy. It can be treated by excision.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.255-265
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• 2009

Recently many studies have been published on application of immediate loaded implants. However, the immediate loading protocol has not been well documented. The purpose of the present study was to evaluate the stress distribution between bone-implant interfaces and the effect of implant length in the anterior maxilla using 3 dimensional finite element analyses. The diameter 4.0 mm threaded type implants with different length(8.5 mm, 10.0 mm, 11.5 mm, 13.0 mm, 15.0 mm) were used in this study. The bone quality of anterior maxillary bone block was assumed to D3 bone. Bone-implant interfaces of immediately loaded implant were constructed using a contact element for simulating the non osseointegration status. For simplification of all the processing procedures, all of the material assumed to be homogenous, isotropic, and linearly elastic. The 178 N of static force was applied on the middle of the palatoincisal line angle of the abutment with $120^{\circ}$ angle to the long axis of abutment. Maximum von Mises stress were concentrated on the labial cortical bone of the implant neck area, especially at the cortical-cancellous bone interfaces. Compared the different length, highest peak stress value was observed at the 8.5 mm implants and the results indicated a tendency towards favorable stress distribution on the bone, when the length was increased. Presence of cortical bone was very important to immediate loading, and it appears that implants of a length more than 13 mm are preferable for immediate loading at the anterior maxilla.

• The Journal of the Korean bone and joint tumor society
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• v.20 no.2
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• pp.74-79
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• 2014

Purpose: Fibrous dysplasia is related to the mutation of gene encoding the alpha-subunit of a signal-transducing G-protein and has variable clinical course. Operation can be performed to prevent functional disorder or structural deformity. After curettage, autologous bone graft were used to fill the defects after curettage. The aim of this study is to compare the result of autogenous cancellous bone grafting and allogenic bone grafting for fibrous dysplasia. Materials and Methods: Among the patients who visit our hospital during the period of April, 1997 to October, 2013, we selected 34 patients who diagnosed fibrous dysplasia and visited our clinic over 1 year. There were 13 males and 21 females. Average age was 26.4 (range 2 to 57) years old. Autogenous bone graft (group I) in 5 cases, Non-autogenous bone graft (group II) in 30 cases. Iliac bone is used in all cases of autogenous bone graft. There were no significant difference in age, follow-up period, preoperational laboratory finding between two groups. Radiographic image was done to evaluate the recurrence of fibrous dysplasia or secondary degeneration. Results: There were four cases in recurrence (group I: 1 case, group II: 3 cases, p=0.554). In all recurrent cases, reoperations were done using curettage and autogenous iliac bone graft. There was no re-recurrence after reoperation. One case of secondary aneurysmal bone cyst was confirmed (group II) and 1 cases of pathologic fractures had developed (group I: 0 case, group II: 1 cases, p=0.559). No malignant change occurred. Conclusion: There were no significant difference between autogenous bone graft group and non-autogenous bone graft group. Our result suggested that autogenous bone graft seems to be good method to treat fibrous dysplasia, in the case of small volume of tumor lesion or non-weight bearing portion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.104-109
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• 1991

Loss of mandibular continuity due to neoplasm, trauma, or infection results in major esthetic and biologic compromise. The use of costochondral grafts for reconstruction of temporomandibular joint, described first by Gillies in 1920, has been accepted as a suitable method for replacing the mandibular condyle, especially in growing children. Autogenous iliac bone graft has been a satisfactory source of mandibular reconstruction since Sykoffs report in 1900. Autogenous bone grafts from the posterior aspects of the ilium provide large amount of PMCB with acceptable donor site morbidity. In timing of reconstruction, initial disease, age, medical history, growth and development, esthetic and psychologic factors should be considered. We present a case of osteosarcoma in the mandible that was treated by a hemimandibulectomy and the defect was reconstructed 20 months later with composite method of costochondral and posterior iliac bone graft.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.4
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• pp.236-241
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• 2011

Mechanical properties of cancellous bone with a high porosity and cortical bone with a high fraction of solid are estimated by the measurement of ultrasonic wave propagation. The speed of sound (SOS) in ultrasonic waves is usually measured by two equations, bulk wave equation and bar wave equation. Bulk wave speed has almost same as the fast wave of Biot's theory. In this study, we examine whether the bulk wave speed is influenced by the anisotropy of bone matrix. The SOS when the bone matrix is isotropy is 0.69% faster than that when the bone matrix is transversely isotropy. We also examine if the use of bar equation is adequate for a cortical bone. In the previous paper, the bar wave speed is a function of Young's modulus or elastic coefficient tensor. In the same manner, the effect of bar wave speed to isotropic and anisotropic bone is estimated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1336-1340
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• 2003

The compressed fracture of spine caused by osteoporosis is one of the most frequent diseases in bone fracture. Recently the vertebroplasty has drawn much attention as a medical treatment for the compressed fracture of spine, which strengthens the vertebral body and corrects deformity, and relieves pain in patients by injecting bone cement. The purpose of this research is to provide the theoretical background for the vertebroplasty by employing scientific methods and thus to find out the improvements of the conventional surgical method. By applying the engineering analysis tools to clinical study, new application fields can also be obtained

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1368-1372
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• 2003

PMMA which is used as the bone cement for vertebroplasty is able to be a supporter, as a fixing supporter role, for broken trabecular structure, caused by the compressed fracture of spine on aged osteoporosis. In this thesis, as experimenting apparent density of bone pieces, we have figured out support extent of Young's modulus as classifying the bone pieces injected PMMA and the others which are not. In case of low apparent density of PMMA in some bone, Young's modulus seems to be more supportable to bone. On the other hand, if apparent density of bones is normal, injection of PMMA is not very effective on improvement in Young's modulus of bone cement injection.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.2
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• pp.73-78
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• 2011

Purpose: This study was aimed to evaluate the result of inlay cortical strut bone grafts for large cysts or cavitary bone lesions in long bones. Materials and Methods: Seven patients with large cyst or cavitary bony lesions were managed with curettage, allogeneic inlay cortical strut and cancellous bone grafts. Additional plate and screw fixations were performed in 6 patients. There were three SBCs, two FDs with secondary ABC changes, one FD and one post-cement spacer removal state. Three of them had pathologic fractures. Progression of bone healing and mechanical support and functional result were evaluated. The mean follow-up period was 25.4 months. Results: Incorporations into host bones were progressed in all, average 4.2 months in six metaphyseal regions and 5.8 months in five diaphyseal regions respectively. Full structural supports were achieved in all except one patient without any additional procedures. No allograft-related complication was developed. Mean functional score according to the MSTS criteria was 29.6 at last follow up. Conclusion: Inlay cortical strut graft provided additional mechanical stability and bone stock for screw purchase in large cyst or cavitary defects of long bones, which allow early mobilization and excellent functional outcome.