• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.430-435
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• 2006

Purpose : The aim of this study was to investigate healed bovine bone particles ($Bio-Oss^{(R)}$) and absorbable collagen sponge ($CollaPlug^{(R)}$) applied extraction socket site at 4-6 months' post-extraction. Material and methods : From August, 2004 to October, 2005, 17 sockets in 5 adult patients were selected out of the patients whose received ridge preservation using bovine bone particles and absorbable collagen sponges at Dept. of oral and maxillofacial surgery in Samsung Medical Center. There were 5 male patients, ages 30 to 58 years. Immediate postoperation and 4-6 months after operation study models were compared to evaluate the ridge dimension by measuring vertical height and horizontal width of alveolar ridge. Results : The measurements at 4-6 months revealed, in the ridge dimension, a loss of vertical height of 0.91${\pm}$0.40mm and horizontal width of 1.25${\pm}$0.58mm. There was no adverse reaction. Conclusion : This study suggests that treatment of extraction sockets with graft materials and collagen sponges is valuable in preserving alveolar bone in extraction sockets and preventing alveolar ridges defects.

• Transactions of Materials Processing
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• v.18 no.1
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• pp.52-58
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• 2009

Generally, a vertical rolling process is used to achieve extensive width reduction in hot strip mill. However, it is impossible to avoid the defects such as dog-bone and edge-seam defect. The sizing press process has been developed in response to the defects mentioned above. Especially, this study is carried out to investigate the deformation of slab by two-step sizing press. The deformation behavior of slab in the sizing press process is more favorable than that in conventional vertical rolling edger. The FE-simulation is applied to predict the deformation behavior of the slab. In this paper, the several causes of the asymmetrical deformation are mentioned for the purpose of understanding of the anvil shape. Load, dog-bone and edge-seam defect are discussed in width sizing process considering the anvil shape. And to reduce the problems generated at rougher mill just after sizing press, these are studied in this paper. The deformation behavior of slabs and optimum anvil shape are obtained by rigid-plastic finite element analyses and neural network.

• The Journal of the Korean dental association
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• v.40 no.9 s.400
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• pp.709-715
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• 2002

Two patients with sufficient vertical bone height but insufficient bone width in the anterior mandibular edentulous area, less than 6mm in the buccolingual aspect, for implant placement were chosen for treatment with a ridge splitting procedure. The surgical technique involving greenstick fracture is described. This ridge splitting procedure could be simple placement of implants into ideal restorable positions in severely atrophic, knife-edged ridges and predictable for narrow edentulous alveolar ridge augmentation associated with implant placement. We experienced two cases to place implant with insufficient bone width in the anterior mandibular edentulous area for overdenture be ridge splitting technique. Thus, we will report two cases and review of the literature.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.8 no.1
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• pp.28-35
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• 1999

The preservation of a healthy periodontal attachment is the most significant factor in the long-term prognosis of a restored tooth. The 'Biologic Width' is composed of the connective tissue attachment and the epithelial attachment in the dentogingival junction. The violation of the biologic width may result in a progressive inflammatory process and crestal bone loss. So a careful soft tissue management is needed to preserve it for the gingival health and an esthetic restoration. The following clinical cases show the five different situations of the violation of the biologic width and their management.

• The korean journal of orthodontics
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• v.40 no.5
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• pp.314-324
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• 2010

Objective: The purpose of this study was to determine differences of mandibular anterior alveolar bone thickness and symphysial cross sectional area in 9 different horizontal and vertical facial types. Methods: By using the initial cephalometric radiographs of 270 adult patients (male 135, female 135), the authors measured the buccolingual thickness of anterior alveolar bone on the basis of the root axis and symphysial cross sectional distance. Results: The high angle group showed significantly thinner buccolingual alveolar bone width except for the CEJ area and lingual alveolar bone width ($p$ < 0.05). The low angle group and Class I, II average group showed similar or significantly thicker alveolar bone width than the Class I average group ($p$ < 0.05). The Class III average group showed significantly thinner buccolingual and lingual alveolar bone width than Class I and II average groups ($p$ < 0.05). The Class III high angle group showed minimal alveolar bone width in all facial skeletal types. No significant difference was found in the symphysial cross sectional area of the different vertical facial skeletal types ($p$ > 0.05). Conclusions: The results of this study found that Class III high angle patients have thinner mandibular anterior alveolar bone thickness; therefore, more attention will be needed to determine the incisor position during orthodontic treatment for this group of patients.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.4
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• pp.526-540
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• 1992

Osteoporosis, a well known metabolic bone disease, occurs due to imbalance of bone formings and resorptions. In an attempt investigate if postmenopausal osteoporosis would have influence on the mandible, histomorphometric analysis was performed in the mandible and the femur of the albino rats. Osteoporosis was induced by bilateral oophorectomy. To determine the effect of calcitonin, calcitonin(Asahi Chemical Co., Japan) was injected in the oophorectomized rats. The results were as follows : 1. The width of cortical bone of the femur was decreased in the oophorectomized group compared to the normal control and calcitonin injected groups and the porosity of cortical bone of the femur was increased in the oophorectomized group compared to the normal control and calcitonin injected groups. 2. The osteoid tissue and resorption lacuna of the femur was increased in both oophorectormized and calcitonin injected groups than the normal control group. 3. The width of cortical bone of the mandible was decreased in the oophorectomized group compared to the normal control and calcitonin injected groups. 4. The porosity of cortical bone of the mandible was decreased in both oophorectomized and calcitonin injected groups than the normal control group. 5. The relative volume of trabecular bone of the mandible was decreased in the oophorectomized group compared to the normal control and calcitonin injected groups. 6. The osteoid tissue of the mandible was increased in the calcitonin injected group than the normal control and oophorectomized groups. 7. The resorption lacuna of the mandible was increased in both oophorectomized and calcitonin injected groups, particularly in the oophorectomized group.

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.89-97
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• 2002

Purpose: The objective of this study is to find the differentiating characteristics of ameloblastomas and odontogenic keratocysts of the jaw by analyzing computed tomography (CT) images of the lesions, clarify radiological characteristics associated with jaw lesions, and to make a diagnsis based on these findings. Materials and Methods : Test subjects were chosen among the patients who were diagnosed as having an odontogenic keratocyst or ameloblastoma at the Yonsei University Dental Hospital from January 1996 to December 2000 and had CT scans taken preoperatively. The subject pool was comprised of 51 cases of odontogenic keratocyst and 37 cases of ameloblastoma. The following measures were used for image analysis of the lesion: the anatomic location, CT pattern, mesiodistal width, buccolingual width, the ratios between mesiodistal width and buccolingual width, height, CT number, homogeneity of radiodensity, the appearance of a sclerotic rim, continuity of adjacent cortical bone, and displacement and resorption of adjacent teeth. Results: Comparing the CT patten, mesiodistal width, buccolingual width, height, CT number, homogeneity, appearance of sclerotic rim, continuity of adjacent cortical bone, there were statistically significant differences between ameloblastoma and odontogenic keratocyst test subjects (p<0.05). Comparing the ratios between mesiodistal width and buccolingual width, displacement and resorption of adjacent teeth, there were no statistically significant differences (p>0.05). Conclusion: We compared odontogenic keratocysts and ameloblastomas in CT scans. They occurred most frequently in the posterior to the ramus of the mandible. The findings of patterns of the CT images showed that size and border of lesions were more aggressive in ameloblastomas than in odontogenic keratocysts. The internal contents represented an increased attenuation area (IAA) in odontopenic keratocyst. Odontogenic keratocysts were shown to have higher CT numbers than ameloblastomas.

• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.577-585
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• 1995

This study has been performed to determine whether significant differences in the maxillary basal bone pattern exist between skeletal class II malocclusion and normal occlusion. Materials for the skeletal Class III sample consisted of lateral cephalometric roentgenograms and maxillary cast models of 29 adult individuals, 15 males and 14 females. The average age was 19.75 years with a range from 16.4 to 29.1 years. A normal control sample consisted of lateral cephalometric roentgenograms and maxillary cast models of 24 adult individuals, 13 males and 11 females. The average age was 24.25 years with a range from 20.8 to 29.4 years. The results of this study can be summarized and concluded as like follows. 1. In comparing sexual difference of maxillary basal bone morphology in skeletal Class III malocclusion, the following Parameters of males were found to be significally larger than those of females : inter first premolar width, inter molar width, oblique canine height, oblique molar height and maxillary basal bone perimeter. 2. In comparing sexual difference of maxillary basal bone morphology in normal occlusion, the following parameters of males were found to be significally larger than those of females : inter canine width, inter first and second premolar width, inter molar width, oblique canine height and oblique molar height. 3. In comparing maxillary basal bone morphologic difference between skeletal Class III malocclusion md normal occlusion in males, the following parameters were found to be significally larger in normal occlusion : inter canine width, inter canine height, inter molar height, oblique canine height and oblique molar height. 4. In comparing maxillary basal bone morphologic difference between skeletal Class III malocclusion and normal occlusion in females, the following parameters were found to be significally larger in normal occlusion : inter canine height, inter molar height, oblique canine height, oblique molar height and maxillary basal bone perimeter.

• The korean journal of orthodontics
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• v.33 no.1 s.96
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• pp.11-20
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• 2003

The purpose of the present study is to evaluate the stress distribution on the length and diameter of the miniscrew and cortical bone width. Three dimensional finite element models were made of diameter 1.2mm, 1.6mm, 2.0mm and length 6.0mm, 8.0mm, 10.0mm, 12.0mm and cortical bone width 1.0mm. Also, another three dimensional finite element models were made of diameter 1.2mm, 1.6mm, 2.0mm and length 8.0mm and cortical bone width 1.0mm, 1.5mm, 2.0mm, 2.5mm. Two-hundred grams horizontal force were applied on the center of the miniscrew head and at that stress distribution and its magnitude had been analyzed by ANSYS, which is three dimensional finite element analysis program. The obtained results were as follows : 1. The comparison of the maximum von-Mises stress in the miniscrew showed that as the diameter increases from 1.2mm to 2.0mm stress has been decreased, while on the same diameter stress was not changed regardless of the length change. 2. The comparison of the maximum von-Mises stress in the cortical and cancellous bone showed that as the diameter increases from 1.2mm to 2.0mm stress has been decreased, while on the same diameter stress was not changed regardless of the length change. 3. In the analysis of the stress distribution in the cortical and cancellous bone, the most of the stress had been absorbed in the cortical bone, and did not transmitted much to the cancellous bone. 4. In the analysis of the maximum von-Mises stress according to the cortical bone width, the same diameter of the miniscrew showed a constant stress value regardless of the cortical bone width change. The above results suggest that the maintenance of the miniscrew is more reliable on diameter than length of the miniscrew.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.321-327
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• 2000

Statement of Problem. As a standard means of diagnostics, an orthopantomogram(OPT) permits to measure the vertical and mesiodistal dimension of available bone at the desired implant site with the help of suitable radioopaque references. Based on the clinical investigation of the dentition and the edentulous sites, information upon the width of the implant site can be obtained and documented in the dental scheme. Both findings permit together systematic primary planning for endosteal implants. Purpose of Study. Contents of the present article are the representation of a semiquantitative classification of available bone with the aim to simplify the primary phase of a systematic implant planning. Results. Thus the ASCIi- system permits a clear protocol of bone findings for the implant case with all information available during the primary appointment for treatment planning as a basis of further diagnostic and therapeutic measures. Conclusion. With the ASCIi system, important parameters such as alveolar height and sub-crestal alveolar width can be documented systematically, easily and time saving in the dental scheme as a basis for exact treatment planning.