• Advances in biomechanics and applications
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• v.1 no.4
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• pp.253-267
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• 2014

The human head is identified as the body region most frequently involved in life-threatening injuries. Extensive research based on experimental, analytical and numerical methods has sought to quantify the response of the human head to blunt impact in an attempt to explain the likely injury process. Blunt head impact arising from vehicular collisions, sporting injuries, and falls leads to relative motion between the brain and skull and an increase in contact and shear stresses in the meningeal region, thereby leading to traumatic brain injuries. In this paper the properties and material modeling of the subarachnoid space (SAS) as it relates to Traumatic Brain Injuries (TBI) is investigated. This was accomplished using a simplified local model and a validated 3D finite element model. First the material modeling of the trabeculae in the Subarachnoid Space (SAS) was investigated and validated, then the validated material property was used in a 3D head model. In addition, the strain in the brain due to an impact was investigated. From this work it was determined that the material property of the SAS is approximately E = 1150 Pa and that the strain in the brain, and thus the severity of TBI, is proportional to the applied impact velocity and is approximately a quadratic function. This study reveals that the choice of material behavior and properties of the SAS are significant factors in determining the strain in the brain and therefore the understanding of different types of head/brain injuries.

• The korean journal of orthodontics
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• v.12 no.2
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• pp.95-108
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• 1982

The purpose of this study was to analyze the growth and development of tooth germ and dental arch related to the bone growth during the fetal period. From 70 maxillae and 61 mandibles of the fetus aged 5, 6, 7, 8, 9 and 10 months, X-ray films were taken and measured. The results were as follows; 1. There was remarkable bone growth in the anterior and posterior area of palatum osseum, that were the intetior portion of both deciduous canines anteriorly and the intero-posterior portion of both deciduous second molars posteriorly, where there was active bone growth and radiate formation of bony trabeculae was found. 2. The Growth of anterior tooth germ was greater than that of posterior tooth germ, so anterior tooth germs were crowded. Especially in maxilla, the tooth germs of deciduous lateral incisors were located inside of dental arch and the tooth germs of deciduous canines were located outside of dental arch. 3. Crowding amount increased with the fetal age because the growth of tooth germs was greater than that of jaw bone. 4. In the growth of upper dental arch, the increase of width was greater than that of length. 5. There was proportional relationship between the area of Palatal Trapezoid and the fetal age.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1078-1080
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• 2002

The pressure variation of interstitial fluid is one of the most important factors in bone physiology. In order to understand the role of interstitial fluid and the biomechanical interactions between fluid and solid constituents within bone, poroelastic theory was applied. The purpose of this study is to describe the behavior of calf vertebral trabecular bone composed of the porous solid trabeculae and the viscous bone marrow by using a commercial finite element analysis program based on the poroelasticity. In this study, the model was numerically tested for 5 different strain rates, i. e., 0.001, 0.01, 0.1, 1.0, and 10 per second. The material properties of the calf vertebral trabecular bone were utilized from the previous experimental study. Two asymptotic poroelastic response, the drained and undrained deformation, were predicted. From the predicted results for the simulated five strain rate, it was found that the pore pressure generation has a linearly increasing behavior when the strain rate is the highest at 10 per second, other wise it showed a nonlinear the strain rate Increased. Based on the results of the present study, it was suggested that the calf vertebral trabecular bone could be modeled as a porous material and its strain rate dependent material behavior could be predicted.

• Journal of Veterinary Clinics
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• v.4 no.2
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• pp.499-504
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• 1987

Two cases of congenital hyperostosis at a pig farm were observed and examined pathologically in Landrace piglets. Twenty two piglets from 2 litters: 10 alive piglets in a litter and 2 stillborn and 10 alive piglets in another, were born with thickened forelimbs and some of them with thickened hindlimbs too. These piglets stowed symptoms of staggering and incoordination. Only one of these piglets could be reared normally and all the others died within 3 days of age. The thickened parts of their limbs were felt firm and not well pitted by finger pressing. An apparent ossification was identified on the central regions of the cross sections of the thickened limbs, and some pale, gray and ossiferous signs were found in the peripheral soft areas. On histopathological examination of the thickened limbs, it was found that the bone trabeculae were newly proliferated in a concentric form in central regions and in a radiated form in peripheral regions. The peripheral regions of the periosteum and perichondrium of new bone were proliferated with connective tissue and the edematous muscle bundles were atrophic and degenerative. Both the sows which produced piglets of congenital hyperostosis were mated with a different boar at next breeding and farrowed normal piglets. It was concluded that the swine congenital hyperostosis in the present cases was expressed by autosomal recessive gene of first mating boar.

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.19-28
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• 1995

The histological and histochemical study of the axis body of piglet was performed in order to clarify the ossification process. These experimental animals collected from after birth to 52 days were used for this study. The results were summarized as follows; 1. The epiphysis, the intercentrum 2 and the centrum of proatlas were appeared in the axis body and dens of piglet after birth. 2. In 39 days of age piglet, the ossification of the intercentrum 2 was first observed but the epiphysis was already initiated. The centrum of proatlas was observed cranioventral part of the dens of the 52 days piglet axis. 3. The notochordal remnants revealed distinctively in the part between the centrum 1 and the centrum2, in the apical cartilaginous tissue of dens and in the caudal cartilaginous part of body of axis. 4. Intramembranous ossification occurred in the adjacent area of perichondrium of centrum 2. These ossified trabeculae show the woven bone configuration.

• Korean Journal of Head & Neck Oncology
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• v.28 no.1
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• pp.27-30
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• 2012

Basaloid squamous cell carcinoma(BSCC) is a high-grade variant of squamous cell carcinoma, with a prediction for multifocal involvement of the base of tongue, pyriform sinus, supraglottic larynx, hypopharynx and palatine tonsil. It primary affects men in the seventh decade of life with frequent cervical lymph-node metastasis at presentation. Grossly, these tumors are usually firm to hard, with associated central necrosis, occuring as exophytic to nodular masses. Histologically, the this infiltrating tumor offers a variety of growth patterns, including solid, lobular, cribriform, cords, trabeculae, nests and glands or cyst. We present a 55-year-old female who was treated with surgical excision and radiotherapy. She was firstly presented as a recurrent inflammatory neck mass and finally diagnosed with basaloid squamous cell carcinoma in the palatine tonsil.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.357-365
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• 1999

Desmoplastic fibroma is a rare. benign intraosseous fibroblastic tumor. which is locally aggressive. It is osseous counterpart of soft tissue fibromatosis. The authors experienced the patient who complained persistent mouth opening limitation with mild swelling on the left mandibular angle area. After careful analysis of clinical. radiological and histopathological findings. we diagnosed as desmoplastic fibroma of the mandible. The results were as follows: 1. Main clinical symptoms were mouth opening limitation which had been persistent for 9 months and mild swelling on the left mandibular angle area. 2. Radiographs showed the radiolucent lesion and expansion of lingual cortex. CT finding is homogeneous soft tissue mass with expansion of left mandibular ramus. Destruction of medial wall of ramus and invasion to adjacent soft tissue is also seen. 3. Histopathologically, plump spindle shaped fibroblasts arranged in bundles or fascicles are observed. The cells of tumor are infiltrating into muscle fiber with destruction of bony trabeculae and merged with surrounding salivary gland.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.569-578
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• 1995

Condylar hyperplasia is a self-limiting condition characterized by a slowly progressing, enlargement of the mandible that results in facial asymmetry and a crossbite malocclusion. The facial asymmetry, open bite or crossbite, and radiographic evidence of an enlarged condyle confirm the diagnosis of condylar hyperplasia. The etiology of the condition is unknown. This condition usually first becomes apparent during the second decade of life, when one condyle continues to grow while the other is no longer active. Radiographically, the condyle may appear enlarged or the neck of the condyle maybe elongated or both may occur, Sometimes, however, no radiographically demonstrable condylar abnormality will be noted. Surgical correction with subcondylar osteotomy is the treatment of choice. We have observed two cases of condylar hyperplasia occurred in the left mandibular condyle of 24-year-old and 35-year-old women. We obtained that two cases were shown the followed results; 1. Clinically, both cases was unilaterally developed on C/C area, with temporomandibular disorders and pain, facial asymetry and malocclusion. 2. Radiographically, hyperplastic mass confined to the condyle. 3. Histopathologically, these cases shown increased hypertrophic region in parts, and lamellated bone with irregular trabeculae.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.1_2
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• pp.124-134
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• 1992

Fibrous dysplasia is a benign pathologic condition of bone in which fibrous tissue gradually expands and replaces normal bone into fibro-osseous lesion. It is a primary developmental abnormality of bone-forming mesenchyme in origin. This study shows clinical history, radiological and histopathological feature of fibrous dysplasia with the intention of establishing correct diagnosis, treatment plan and evaluation of prognosis. This paper reviews and summarizes the materials from 57 fibrous dysplasias submitted to the Department of Oral and Maxillofacial Surgery in College of Dentistry, Seoul National University. Conclusions obtained were as following : 1. Fibrous dysplasia developed mainly in teenagers and shows female predeliction. 2. Fibrous dysplasia developed much on the maxilla 3. Monostotic fibrous dysplasia was most popular form. 4. Main symptom of fibrous dysplasia was painless swelling. 5. Radiological feature of fibrous dysplasia was ground-glass appearance, 6. Histopathological feature of fibrous dysplasia was irregular immature bony trabeculae(woven bone). 7. Treatment of fibrous dysplasia was mainly conservative contouring surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.2
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• pp.157-161
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• 1994

A 14-year-old male patient was referred to us for evaluation of Right TMJ clicking sound and mandibular deviation during mouth opening. On examinaaation, protrusion and lateral excursion was also restricted. Radiographs showed hook-like curved elongation of Right coronoid process with limitation o right condylar translation. His past medical and dental history was noncontributory. This patient underwent an extraoral coronoidectomy and the specimen revealed coronoid process malformation mimicking condylar head. Microcoically, the specimen discloses mature bony trabeculae. At postoperative 5 days, physical therapy was instituted. At present, this patient could open his mouth well with any clicking sound and mandibular deviation. The asymmetric face of this patient is expectated to be corrected by periodic observation and remained growth porential. If not to be corrected, orthognathic surgery will be done.