• 치과방사선
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• 제29권1호
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• pp.43-53
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• 1999

Purpose: The aim of this study was to analyze radiologically the location and course of the mandibular canal and to observe the alveolar and basal bone changes during the remodeling procedures of atrophic mandible. Materials and Methods: CT scanning was performed on dry 30 edentulous or partially dentulous mandibles. In 48 edentulous lower halves, measuring areas were determined by three points in the length of the mandibular canal. The distance from the mandibular canal towards cranial and caudal edges, buccal and lingual external borders of the body of the mandible were measured. A statistical comparison between the mean values of different classes of mandibular body was carried out in the selected areas. Results: The distance between the mandibular canal and caudal borders of the body of the mandible and lingual borders dose not change in the atrophic process of mandible. The mandibular canal within the mandible courses downwards from mandibular foramen towards mesial and subsequently it gets to the mental foramen. The distance between the mandibular canal and buccal external border of basal bone changes similar to the change of cranial borders of alveolar bone in the atrophic process of mandible. Conclusion: CT scanning was very effective and practicable to analyze the location and course of the mandibular canal and to observe the alveolar and basal bone changes of atrophic mandible. Also more detailed investigation of basal bone changes observed during the remodeling procedures of atrophic mandibles seems reasonable to rely on the massive anthropologic collections of atrophic mandibles combined with CT scanning.

• Archives of Plastic Surgery
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• 제38권3호
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• pp.222-227
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• 2011

Purpose: Autogenous particulate bone grafting is a type of autogenous bone graft that consists of small particles of cortical and cancellous bone. Autogenous particulate bone grafting has been used for calvarial bone defect after calvarial defect of craniosynostosis and prevention of temporal depression after fronto-orbital advancement. The results were followed up and studied for effectiveness of autogenous calvarial particulate bone grafting. Methods: Cranial vault remodeling and fronto-orbital advancement was performed for six craniosynostosis patient from August 2005 to October 2007. Autogenous particulate bone grafting was harvested from endocortex of separated cranial vault and if insufficient, from extocortex of occipital region using Hudson brace & D'Errico craniotomy bit and was grafted on the calvarial bone defect of cranial vault and temporal hollow. Fibrin glues were added to the harvested particulated bone for adherence and shaping of paticles. Results: Autogenous particulate bone grafting was followed-up at least longer than I year. The calvarial bony defects following primary cranial remodeling were successfully covered and postoperative temporal depressions after fronto-orbital advancement were also well prevented by grafted particulated bone. Conclusion: Autogenous calvarial particulate bone graft can be harvested in infants and young children with minimal donor site morbidity. It effectively heals cranial defects in children and during fronto-orbital advancement reduces the prevalence of osseous defects independent of patient age. It's easy and effective method of reconstruction of calvarial defect.

• 대한치과보철학회지
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• 제32권4호
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• pp.573-592
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• 1994

A two-stage procedure is ideal for getting a successful osseointegration. But if a one-stage procedure can achieve a similar osseointegration, the one-stage procedure has several advantages. The purpose of this study was to observe the initial bone formation and bone remodeling of open type (nonsubmerged) and closed type (submerged) titanium implants. Eight ITI hollow-screws and eight Branemark fixtures were divided into two groups (submerged and nonsubmerged) and were installed on the lower jaws of four mongrel dogs. The animals were sacrificed three months later and bone sections with implants were processed for light microscopic and fluorescent microscopic observation. The results were as follows : 1 There was no significant difference in bone-to-implant contact between submerged and nonsubmerged implants. 2. Smooth surface titanium implants showed more bone-to-implant contact than that of titanium plasma coated implants histologically. 3. Under fluorescent microscopy, the active bone remodeling and new bone formation were observed in the interface zone. 4. Under fluorescent microscopy, submerged and nonsubmerged implants had no difference in bone remodeling pattern, and intramembranous bone formation was more prominent. 5. The connective tissue fibers orienting perpendicularly toward implant surface were oberved in the neck of implants.

• Journal of Periodontal and Implant Science
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• 제49권1호
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• pp.25-38
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• 2019

Purpose: This study evaluated differences in bone healing and remodeling among 3 implants with different surfaces: sandblasting and large-grit acid etching (SLA; IS-III $Active^{(R)}$), SLA with hydroxyapatite nanocoating (IS-III $Bioactive^{(R)}$), and SLA stored in sodium chloride solution ($SLActive^{(R)}$). Methods: The mandibular second, third, and fourth premolars of 9 dogs were extracted. After 4 weeks, 9 dogs with edentulous alveolar ridges underwent surgical placement of 3 implants bilaterally and were allowed to heal for 2, 4, or 12 weeks. Histologic and histomorphometric analyses were performed on 54 stained slides based on the following parameters: vertical marginal bone loss at the buccal and lingual aspects of the implant (b-MBL and l-MBL, respectively), mineralized bone-to-implant contact (mBIC), osteoid-to-implant contact (OIC), total bone-to-implant contact (tBIC), mineralized bone area fraction occupied (mBAFO), osteoid area fraction occupied (OAFO), and total bone area fraction occupied (tBAFO) in the threads of the region of interest. Two-way analysis of variance (3 types of implant $surface{\times}3$ healing time periods) and additional analyses for simple effects were performed. Results: Statistically significant differences were observed across the implant surfaces for OIC, mBIC, tBIC, OAFO, and tBAFO. Statistically significant differences were observed over time for l-MBL, mBIC, tBIC, mBAFO, and tBAFO. In addition, an interaction effect between the implant surface and the healing time period was observed for mBIC, tBIC, and mBAFO. Conclusions: Our results suggest that implant surface wettability facilitates bone healing dynamics, which could be attributed to the improvement of early osseointegration. In addition, osteoblasts might become more activated with the use of HA-coated surface implants than with hydrophobic surface implants in the remodeling phase.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권1호
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• pp.55-59
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• 2013

In the oral and maxillofacial area, bone defects are created by various reasons and demand for bone grafts, while dental implant implantation has been increased consistently. To solve these problems, there has been development of autogenous tooth-bone graft material (AutoBT$^{(R)}$, Korea Tooth Bank Co., Korea), and we have collected ground reasons to substitute free autobone graft with this material in clinical use. This autogenous tooth-bone graft material is produced in powder type and block type. Block type is useful in esthetic reconstruction of the defect site and vertical and horizontal augmentation of alveolar bone because this type has high strength value, well maintained shape and is less absorbed. Therefore, the author of this study gained favorable result by grafting the block type autogenous tooth-bone graft material after dental implant implantation on the bone defects of the mandibular molar extraction site. Moreover, the author represents this case with literature review after confirming bone remodeling on the computed tomography image and by histological analysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권6호
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• pp.654-659
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• 2007

We performed sinus bone graft using some amount of autogenous bone and $BioOss^{(R)}$ and covered the sinus window with $Ossix^{(R)}$ membrane in these case series. After 4 to 6 months after operation, histopathologic examinations of trephine core biopsy showed following results. 1. There were bone density of 39.2% to 41.2% four months after operation, and we could observe the favorable early new bone formation. 2. Active bony remodeling of woven and lamellar bone was observed during 4 to 6 months healing period. 3. There were no significant differences between two groups. And also there were no significant differences between 4 months and 6 months.

• 대한두개안면성형외과학회지
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• 제15권2호
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• pp.63-69
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• 2014

Background: A number of studies have reported complication after reduction of nasal bone fractures. Among complicated cases, some showed improvement in shape of the nose with passage of time. Therefore, we examined these changes using computed tomography (CT) images taken over intervals. Methods: CT scans of 50 patients with new nasal bone fractures were reviewed, and the images were compared amongst preoperative, immediately postoperative, and one month scans. Changes in nasal bone shape, were evaluated based on the angle of nasal bone arch between the nasal bone and frontal process of maxilla, overall shape of arch, mal-alignment of fracture segments involving bony irregularity or bony displacement. These evaluations were used to separate postoperative outcomes into 5 groups: excellent, good, fair, poor, and very poor. Results: Immediate postoperative nasal shape was excellent in 10 cases, good in 31 cases, fair in 8 cases, and poor results in a single case. Postoperative shape at one month was excellent in 37 cases, good in 12 cases, fair in a single case. Conclusion: The overall shape of nasal bone after fracture reduction tended to improve with passage of time.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.141-145
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• 2002

Purpose : The purpose of this study was to propose standard values for alveolar and basal bone in normal adult mandibles, and radiologically analyze the remodeling process of the edentulous mandible by examining molar areas and comparing them to the established normal values. Materials and Methods : Panoramic and CT scans of mandible were performed on 20 normal adults and 20 edentulous or partially edentulous adults. In both groups, arch half diameter and distance of alveolar bone were measured. Also the distance from the mandibular canal to the caudal edges, the buccal and lingual external borders of basal bone, were measured. A statistical comparison between the mean values of normal and edentulous mandibles was carried out in the selected areas. Results : There was evidence of decreasing arch half diameter and distance in the edentulous mandible, but statistically no significant change was seen between the normal and edentulous alveolar bone. There was evidence of decreasing buccal basal bone and increasing in the lingual basal bone in the edentulous mandible. A statistically significant difference between normal and edentulous mandibles was noted in the buccal basal bone. Conclusion: There was an inward and forward atrophic change of the edentulous mandibular molar area compared to the control. CT scanning required the use of sophisticated and expensive procedures to analyze the remodeling process of edentulous mandibles. Consequently, the development and application of a more simplified and objective radiographic procedure for broad and long-term study of remodeling procedures of edentulous mandible was recommended.

• 대한의용생체공학회:의공학회지
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• 제21권4호
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• pp.373-384
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• 2000

본 연구의 목적은 체적 변형률 (volumetric strain)에 의한 스폰지 뼈의 밀도를 예측하는 것이다. 스폰지 뼈의 내부에서 유체의 흐름을 고려하기 위하여 각각의 normal strain의 합을 체적 변형률로 정의하였다. 체적 변형률의 경계조건에 대한 민감한 반응은 스폰지 뼈의 밀도를 예측하도록 하였다. 이러한 이론적 배경을 유한요소법 (finite element method)에 적용시켜 대퇴골 (femur)과 척구 (spine)의 스폰지 뼈에서의 밀도를 예측하였다. 예측된 뼈의 밀도는 실험적 데이터와 매우 유사하였다. (Wolff 1892, Keller et al. 1989, Codyet al. 1992). 뼈의 밀도의 함수인 뼈의 탄성계수와 강도 또한 실험적 결과와 매우 유사하였다. (Keller et al. 1989, Carter and Hayes 1977). 본 연구에서 정립된 알고리즘은 스폰지 뼈의 밀도를 예측하는데 있어서 수렴성과 민감성이 우수하였다. 따라서 본 연구의 컴퓨터 알고리즘은 스폰지 뼈의 밀도예측에 있어서 매우 유용한 방법이 될 것이다.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.727-738
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• 2001

Macrophagal polykaryocytes (MPs) are terminally differentiated multinuclear macrophage cells responsible for remodeling and resorption of bone, foreign body, and tissue deposition in inflammation. MPs are encountered only in bone and cartilagenous tissues, in which they are referred to as osteoclasts, odontoclasts, in which they are referred to as osteoclasts, odontoclasts, and septoclasts. Depending on the disease, the MPs differentiate into many morphological variants that include foreign-body giant cells, Langhans-type cells, and Touton-type cells. Morphological heterogeneity of MPs could Touton-type cells. Morphological heterogeneity of MPs could reflect the giant cell formation from phenotypically different marophage precursors by the process of fusion. At present, many cytokines, adhesion/fusion molecules, and other factors of the microenvironment have been discovered that influence the multinucleation process. Many evidences suggest that conditions in giant cell fibrohistiocytomas, which facilitate MP formation, are similar to the inflammation site of granulomatosis. MPs in the giant cell tumors and granulomatosis foci are formed in response to the factors secreted by mesenchymal cells. It is proposed that one of the first steps in vertebrate evolution could be the organization of skeleton remodeling, in which osteoclasts play a major role. In this step, the same mechanism of regulations served as a basis for the development of both osteoclast and inflammatory forms of MPs.