• Journal of Periodontal and Implant Science
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• 제37권2호
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• pp.277-286
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• 2007

The edentulous posterior maxilla generally provides a limited amount of bone height because of atrophy of the ridge and pneumatization of the maxillary sinus, Maxillary sinus augmentation is one of the surgical techniques for reconstruction of the severely resorbed posterior maxilla. The purpose of this study was to evaluate the survival rate of implants and the long-term changes of graft height after maxillary sinus augmentation by lateral window approach. From September 1996 to July 2004, maxillary sinus augmentation with mixed grafts of autograft, allograft, xenograft and alloplast were performed on 45 patients and 100 implants were placed. We evaluated the survival rate of implants and the changes of BL(bone length)/IL(implant length) according to time using panoramic radiographs. The survival rate of implants was 91.0% for follow-up period. The mean reduction of graft heights was 0.34mm(3.0%) for 6 months and 1.22mm(1O.66%) for 3 years after augmentation. The total mean BL/IL was $1.34{\pm}0.21$ during 5 year observation period after augmentation and decreased slightly over time. The result means that graft materials were stable above the implant apex. BL/ILs of 1stage procedure were significantly decreased at 1-2 year, 3-4 year after augmentation and no statistically significant changes were observed in those of 2 stage procedure. The graft materials of both procedures were stable above the implant apex. No statistically significant changes of BL/IL were observed in the grafts combined with low amount of autogenous bone or without autogenous bone. The graft materials of both groups were stable above the implant apex. The results indicated that the placement of dental implants with maxillary sinus augmentation showed predictable clinical results and the grafts combined with low amount of autogenous bone or without autogenous bone had long-term resistance to resorption in maxillary sinus.

• 치과방사선
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• 제19권1호
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• pp.137-147
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• 1989

CT findings of proven 25 malignant tumors of the maxillary sinus were retrospectively analyzed to be of help in the diagnosis and treatment. The results were follows: 1. Average age was 54 years old, and eighteen were males and seven were females with a ratio of 2.6:1 2. The most common histopathologic feature was squamous cell carcinoma (19 cases) and others were two cases of adenoid cystic carcinoma, one case of malignant fibrous histiocytoma, mucoepidermoid tumor, histiocytic lymphoma, unidentified malignant tumor. 3. CT findings were sinus opacificaqtion (4%), soft tissue mass (92%), low densities within soft tissue mass (44.%), air densities within soft tissue mass (24%), osteosclerosis (4%), bone destruction (92%), bone displacement (32%), fat plane obliteration (76%). 4. CT in the malignant maxillary sinus tumors approved the value in evaluation of tumor extension to nasal cavity, ethmoid sinus, orbit, infratemporal fossa, pterygopalatine fossa, pterygoid fossa, pterygoid muscle, cheek skin and intracranial cavity. 5. Twenty four cases (96%) were stage Ⅲ, stage Ⅳ according to AJCC TNM classification. 6. Bone findings were destruction, displacement, sclerosis and most frequent site of bone destruction was the medial wall of the antrum(92%). 7. Tumor growth pattern showed destructive pattern in 18 cases(72%), and squamous cell carcinoma showed destructive pattern. (P<0.05)

• 대한치과교정학회지
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• 제49권3호
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• pp.150-160
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• 2019

Objective: This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods: In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results: When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions: The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

• 대한치과교정학회지
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• 제24권3호
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• pp.621-630
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• 1994

The purpose of this study was to evaluate root resorption and alveolar bone resorption pattern by jiggling movement. 16 adult cats were divided into 4 groups(6, 12, 18, 24 days). In test side, mesio-distal jiggling force was applied in right maxillary 1st premolar in 3 days cycle In control side, mesial force was applied in left maxillary 1st premolar. Radiographic and histologic observation were performed in 6, 12, 18, 24 days after force application. The results were as follow: 1. Alveolar bone resorption was more severe by jiggling force than by unidirectional force. 2. Root resorption pattern was not different between jiggling force and unidirectional force. 3. Combined pattern of bone resorption and new bone formation appeared in jiggling group. 4. New bone formation began to appear at periapical area of jiggling group after 24 days, because alveolar bone resorption was severe and extrusion resulted.

• 치과방사선
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• 제14권1호
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• pp.71-80
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• 1984

The author has studied each landmark for successful interpretation in the radiograph of the head that have the complex anatomic structures, using panoramic radiograph, postero-anterior cephalometric radiograph, lateral cephalometric radiograph, Waters' radiograph of the skull. The anatomic structures of the human dry skull attached by radiopaque materials were taken radiographs and analysed comparatively. The results were as follows: 1. The overall anatomic structures of the mandible showed sharp images in the panoramic radiograph than other radiographs with relatively less distortion, superimposition, blurring of the image. 2. The anatomic structures were situated on sagital plane of the skull showed blurred images in panoramic radiograph than other radiographs. 3. The anatomic structures which were situated on the basal portion of the skull showed blurred and secondary images in the panoramic radiograph than other radiographs. 4. In the panoramic radiograph, the lower 3rd portion of the orbit appeared to be superimposed with the superior portion of the maxillary sinus and the medial and lateral surface of the nasal cavity showed extensively superimposition of the orbit and the maxillary sinus, which images showed blurring. 5. The inferior surface and posterior surface of maxillary sinus showed to be good image in the panoramic radiograph than other radiographs. 6. In the panoramic radiograph, line of maxillary bone between lateral pterygoid plate, line of maxillary bone between zygomatic bone showed distinct image with another structures.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권2호
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• pp.167-172
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• 2009

The maxilla rarely undergoes necrosis due to its rich vascularity. Maxillary necrosis can occur due to bacterial infections such as osteomyelitis. viral infections such as herpes zoster and fungal infections such as mucormycosis, aspergillosis etc. Herpes zoster is a common viral infection, the oral soft tissue manifestations of which are widely known and recognized. Extremely rare complications such as osteonecrosis, and secondary osteomyelitis in maxilla were observed. But, reports of spontaneous tooth exfoliation and jaw osteonecrosis following herpes zoster infection in the distribution of the trigeminal nerve are extremely rare in the literature. We report a case of maxillary necrosis by herpes zoster in an uncontrolled diabetic patient. There was extensive necrosis of the buccal and palatal mucoperiosteum and exposure of the alveolar bone. This patient was successfully treated using a removal of necrotic bone and nasolabial flap. We briefly discuss different diseases which can lead to maxillary necrosis and a review. Analysis of the pathogenesis of herpes zoster and bone necrosis are discussed.

• 대한치과교정학회지
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• 제46권5호
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• pp.310-322
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• 2016

Objective: The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. Methods: A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. Results: The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. Conclusions: Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss.

• 대한치과보철학회지
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• 제47권2호
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• pp.240-246
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• 2009

연구목적: 이 연구는 측방접근법을 통해 상악동 골이식을 시행한 후 임플란트를 식립하였을 때, 누적 생존률 및 성별, 연령별, 이식재, 자가골의 공여부, 술전 잔존골 양, 무치악 형태, 식립 시기, 임플란트 종류, 직경과 길이에 따른 임플란트의 생존률 및 변연골의 방사선학적 결과의 차이를 분석하고자 시행되었다. 연구 재료 및 방법: 상악 구치에 측방접근법을 통해 상악동 골이식술 후 임플란트 보철치료를 시행한 71명을 대상으로 하였으며 표면 처리된 나사모양의 임플란트를 사용하였다. Osseotite(BIOMET 3i, Warsaw, USA), Neoplant(Neobiotec, Seoul, Korea), $Br\ddot{a}nemark$(Nobel Biocare, Goteberg, Sweden)과 SSII(Osstem, Busan, Korea)를 사용하였다. 최소 6개월 이상의 기간 관찰 누적 생존률은 Kaplan-Meier 분석법을 이용하였으며 다른 요소에 따른 임플란트의 생존률의 유의성은 Chi-square test로 검정하였다. 결과: 상악동골 이식술이 시행된 모든 증례에서 임플란트 식립이 가능한 골 양이 얻어졌으며 92%의 생존률을 보였다. 결론: 상악동 골이식술을 시행한 후 임플란트 보철 수복은 자가골 단독 사용시에 자가골과 골대체 물질이 혼합된 것보다 우수한 생존률을 보였다. 지연 식립하는 경우가 임플란트와 동시에 식립하는 경우보다 생존률이 높았다.

• 대한치과교정학회지
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• 제25권5호
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• pp.577-585
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• 1995

본 연구는 골격성 3급 부정교합 환자의 악교정 수술시 나타날 수 있는 중안모의 부조화에 대해 영향을 미치는 하부 경조직 특히 상악 기저골 형태에 관해 연구해 보고자 단국대학교 치과대학 부속치과병원 교정과에 내원하여 술전 교정치료 및 술후 교정치료 중인 성인 환자 남성 15명, 여성 14명, 총 29명과 대조군으로 동 교정과에서 소장하고 있는 성인 정상 교합자의 자료 중 남성 13명, 여성 11명, 총 24명을 대상으로 측모 두부 방사선사진과 상악 석고모형을 이용하여 두 군간의 상악 기저골에 대한 형태적 차이를 연구해 본 결과 다음과 같은 결론를 얻었다. 1. 골격성 3급 부정교합군의 상악 기저골 형태에 대한 성별간의 비교 결과, 여성 보다 남성에서 제1소구치부 폭경, 제1대구치부 폭경과 oblique canine height, oblique molar height 그리고 상악 기저골 둘레 길이가 더 크게 나타났다. 2. 정상교합군의 상악 기저골 형태에 대한 성별간의 비교 결과, 여성 보다 남성에서 견치부 폭경, 제1, 제2소구치부폭경, 제1대구치부 폭경 그리고 oblique canine height, oblique molar height가 더 크게 나타났다. 3. 골격성 3급 부정교합군과 정상교합군 중 남성간의 상악 기저골 형태 비교에서 정상교합군의 견치부 폭경과 견치부 장경, 제1대구치부 장경, oblique canine height, oblique molar height가 3급 부정교합군 보다 더 크게 나타났다. 4. 골격성 3급 부정교합군과 정상교합군 중 여성간의 상악 기저골 형태 비교에서 정상교합군의 견치부 장경, 제1대구치부 장경, oblique canine height 그리고 oblique molar height 와 상악 기저골 둘레길이가 3급 부정교합군 보다 더 크게 나타났다.

• 대한치과교정학회지
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• 제23권2호
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• pp.263-273
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• 1993

The purpose of this study was to analyse the center of resistance of the maxillary first molar using the 3-dimension finite element method. An extracted maxillary first molar of normal shape and average root length was selected and sectioned every 1.5mm parallel to the cementoenamel junction. Each section was traced and digitized to construct 3-D finite element model of the maxillary first molar. After a certain magnitude of counterbalancing moment(M) was applied to the tooth, a varying single force(F) of distomesial direction was applied to a certain point of th tooth until the tooth was translated. The force producing translation(Ft) was substituted to the equation ${\Delta}d=M/Ft$ to calculate the center of resistance of the maxillary first molar. And reducing the alveolar bone level 1.68mm, and 3.36mm below to the cementoenamel junction, the tooth movement was analysed to see the effect of reducing the alveolar bone level to the location of the center of resistance. The results were as follows ; 1. The center of resistance of the maxillary first molar was 3.72mm apical, 1.10mm buccal, and 0.71mm mesial to the geometric center of the horizontally sectioned surface at the cementoenamel junction. This point was 0.36mm apical, 1.20mm buccal, and 0.71mm mesial to the trifurcation point, indicating that it was not on the tooth root. 2. As the alveolar bone level was reduced, the center of resistance of the maxillary first molar was moved to the apical direction.