• 대한치과교정학회지
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• 제26권4호
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• pp.441-447
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• 1996

본 연구는 상악 전돌증을 보이는 환자에게서 상악 제 1 소구치를 발치한 후 견인시 bracket 종류에 따른 치근흡수 차이, 이동양상에 따른 치근 흡수 차이, 각 치아간에 따른 전치부의 치근 흡수 정도를 연구하기 위해 단국 대학교 부속 치과 병원 교정과에 내원한 남녀 환자 32명을 대상으로 연구하여 다음과 같은 결과를 얻었다. 1. 상악 전치 후방 견인시 치근 흡수를 보이지 않는 것은 31.77%, 약간의 흡수는 33.33%, 치근의 1/4이하 흡수는 23.96%, 1/4이상은 10.94%를 보였다. 2. Apical tipping, lingually bodily movement, ant-post apical displacement 의 세가지 이동 양상은, 치근 흡수와의 상관 관계에 유의한 차이를 보이지 않았다. 3. Standard br.을 사용한 환자는 많은 치축 변화를 보이고 치근첨의 이동은 적었으나, straight br.을 사용한 환자는 적은 치축 변화를 보이고 치근첨의 이동량은 많았다. 4. Standard br.과 straight br.의 치근흡수에서 standard br.을 사용한 환자가 더 많은 치근 흡수를 보였다. 5. Standard br.을 사용시 치근 흡수정도는 2>1>3=0순을 보이고, straight br.을 사용시에는 0>1>2>3으로 나타났다.

• Journal of Periodontal and Implant Science
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• 제44권5호
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• pp.216-221
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• 2014

Purpose: This retrospective study compares the amount of bone resorption around implants between an autogenous tooth bone graft (AutoBT) and a synthetic bone graft after a bone-added crestally approached sinus lift with simultaneous implant placements. Methods: In all, 37 patients participated in this study. Seventeen patients were grouped as group I and underwent an AutoBT-added sinus lift using the crestal approach. The remaining 20 patients were grouped as group II and underwent synthetic bone grafting. Both groups received the implant placements simultaneously. Of the 37 participating patients, only 22 patients were included in the final results: Eleven patients of group I and 11 patients of group II. Before the surgery, the distance from the alveolar crest to the sinus floor was measured using panoramic radiography. After the surgery, the distance was measured again from the neck of the implant thread to the most superior border of the added graft materials. Then, the amount of sinus lift was calculated by comparing the two panoramic radiographs. After a year, a panoramic radiograph was taken to calculate the resorption of the bone graft material from the radiograph that was taken after the surgery. The significance of the resorption amount between the two types of graft materials was statistically analyzed. Results: The bone height was increased to an average of 4.89 mm in group I and 6.22 mm in group II. The analysis of panoramic radiographs 1 year after the surgery showed an average bone resorption of 0.76 mm and 0.53 mm, respectively. However, the degree of lifting (P=0.460) and the amount of bone-grafted material resorption (P=0.570) showed no statistically significant difference. Conclusions: Based on this limited study, AutoBT can be considered a good alternative bone graft to a synthetic bone graft in a bone-added sinus lift, when extraction is necessary prior to the surgery.

• Imaging Science in Dentistry
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• 제52권2호
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• pp.165-170
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• 2022

Purpose: This report presents a case of an unusual and rare presentation of Stafne bone defect (SBD) with apical resorption extending from the lower right lateral incisor to the right first premolar. A systematic search of the current literature on cases where SBD affected the adjacent teeth was conducted. Materials and Methods: From 259 identified articles, 114 studies were examined, containing 12 individuals with a mean age of 41.58 years. Ten cases in the anterior mandible and 2 in the posterior mandible were found. Results: The results of SBD varied from apical blunting to severe root resorption, and some cases showed close apical contact with the lesion or involvement of the root without any effect. Conclusion: SBD is an unusual incidental finding in the anterior region of the mandible, and unexpected behavior of the lesion, such as root resorption, must be considered.

• 대한치과교정학회지
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• 제44권6호
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• pp.320-329
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• 2014

Objective: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. Methods: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). Results: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. Conclusions: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

• 대한치과의사협회지
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• 제57권12호
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• pp.768-777
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• 2019

Alveolar bone resorption are unpredictable and always occur after tooth extraction. Such bone resorption causes insufficient alveolar ridge which make implant placement difficult. There are many techniques to increase the alveolar ridge. Representative procedures include ridge split, guided bone regeneration, bone graft using autogenous block bone, and alveolar distraction. In each procedure, there are indications and complications. Depending on the shape and the width of bone defects, we can choose procedures for horizontal bone augmentation and vertical bone augmentation.

• 치과방사선
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• 제22권2호
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• pp.339-348
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• 1992

The purpose of this study was to evaluate the correlationship between histopathologic types of ameloblastoma and their radiographic appearances. The materials for this study consisted of 106 patients diagnosed as ameloblastoma both radiographically and histologically. The obtained results were as follows: 1. The incidence of ameloblastoma in male(60cases, 56.6%) was slightly higher than that in female (46 cases, 43.4%). The average age was estimated as 30.7 years with a range from 6 to 76 years. The second decade revealed the highest rate. 2. 106 ameloblstomas were histopathologically classified as 36 unicystic, 28 plexiform, 20 follicular, 14 acanthomatous, 7 granular cell, and 1 basal cell ameloblastoma. 3. Unilocular, soap-bubble appearance and scalloped margin were the radiographic appearances frequently seen in unicystic ameloblastoma. The predominant radiographic appearance of plexiform ameloblastoma showed unilocular radiolucency with scalloped margin. 4. 19.8%, 21 cases of ameloblastoma in this study showed containing tooth in their tumor mass by radiography. 5. Root resorption occured in 37 cases(34.9%) and tooth displacement in 7 cases(6.6%). Root resorption and tooth displacement occured in same patient were 24 cases(22.6%). 6. Recurrence occured in 21.7% and average year between initial treatment and recurrence were 2 years.

• Journal of Periodontal and Implant Science
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• 제49권3호
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• pp.148-157
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• 2019

Purpose: This study aimed to evaluate periodontal and pulpal healing in replanted rat teeth, preserved under different storage conditions, with or without root conditioning using doxycycline. Methods: A total of 40 maxillary first molars extracted from 20 Sprague-Dawley rats were stored for different durations under different conditions (5 minutes in dry storage and 60 minutes in Hank's balanced salt solution [HBSS]) and subsequently replanted. The rats were divided into 2 groups based on the use of root surface treatment: the doxycycline group (root surface treated with doxycycline) and the control group (no doxycycline treatment). Eight weeks after replantation, the animals were sacrificed, and the teeth were evaluated using micro-computed tomography (micro-CT) and histomorphometric analysis. Results: In the micro-CT analysis, the doxycycline group showed the same rate of occurrence of periapical radiolucency as was observed in the control group, but a lower degree of root resorption in teeth replanted after 60 minutes of storage in HBSS (P<0.05). In the histomorphometric analysis, the doxycycline group exhibited no improvement in either pulpal or periodontal healing of the replanted tooth after 5 minutes of dry storage, but showed a lower grade of surface root resorption ($1.37{\pm}0.77$) and inflammatory resorption in the teeth stored for 60 minutes in HBSS ($1.33{\pm}0.71$). Conclusions: In conclusion, doxycycline improved the periodontal healing of replanted teeth stored for 60 minutes in HBSS, whereas doxycycline did not improve periodontal healing of replanted tooth after 5 minutes of dry storage. Within the limits of this study, doxycycline showed more favorable periodontal healing despite delayed replantation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권4호
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• pp.445-449
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• 2008

Unerupted or erupted supernumerary tooth may cause crowding, diastema, cyst formation, resorption, and displacement or rotation of adjacent teeth. However, there are few studies about prognosis about the pathologic condition and expectation of spontaneous eruption. The object of this study is to evaluate factors predicting the spontaneous eruption of supernumerary tooth. 431 patients (346 males and 85 females, aged from 5 to 29 years) who visited our institution from 2002-2006 and were shown to have 471 mesiodentes was reviewed. Supernumerary teeth were classified inverted and not inverted state. In case of not inverted supernumerary tooth, eruption rate ac cording to length of supernumenary tooth, width of the tooth, angle between the tooth and incisor tooth, location (inside the incisor or not) and shape (conical or tubercle) were investigated. The regression model showed that length, width and angle were all important determinants of influencing the eruption of supernumerary tooth (p < 0.001, Pearson R: 0.619). There is no relation between shape and eruption of supernumerary tooth (p > 0.05). Location of mesiodens has an effect on eruption of supernumerary tooth (p < 0.01).

• 대한소아치과학회지
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• 제27권4호
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• pp.524-534
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• 2000

유치 치근 흡수가 일어나는 경우는 임상에서 많이 접할 수 있다. 유치 치근 흡수는 나이에 따른 생리적 흡수와 치아우식증 및 외상 등으로 비정상적으로 흡수되는 염증성 흡수로 나눌 수 있다. 염증성 흡수는 그 시기와 양상이 생리적인 치근 흡수와는 다르며, 흡수기전이나 흡수면의 미세구조에 있어서도 많은 차이가 있을 것으로 사료된다. 유치 치근 흡수면의 미세구조에 대한 연구는 많이 있었으나, 생리적 흡수면과 염증성 흡수면의 미세구조를 비교한 연구는 드물다. 본 연구는 생리적 흡수면과 염증성 흡수면의 형태 및 인접한 세포를 연구하기 위하여 생리적 및 염증성 흡수로 인해 발거된 유치 치근의 흡수 표면을 주사전자현미경상으로, 조직학적 형태를 광학현미경상으로 관찰하여 다음과 같은 차이점을 알 수 있었다. 1. 주사전자현미경상에서 생리적 유치 치근 흡수 표면은 타원형, 원형 및 다각형 모양의 흡수소와가 관찰되었고, 염증성 흡수 표면은 크기가 작으며 형태가 다양하고 매우 불규칙한 무정형 형태의 흡수소와가 관찰되었다. 2. 광학현미경상에서 생리적 유치 치근 흡수면은 흡수소와로 구성된 규칙적인 큰 흡수와가 관찰되었고, 염증성 흡수면은 불규칙한 흡수소와가 관찰되었다. 3. 광학현미경상에서 생리적 유치 치근 흡수면에는 다핵거대세포가 흡수소와에 직접 접하고 있었으며, 염증성 흡수면은 간엽세포 및 염증세포가 많이 관찰되었다. 4. 광학현미경상에서 염증성 치근 흡수면에서는 상아질 흡수를 보상하는 부분적인 백악질 형성이 관찰되었다.

• International Journal of Oral Biology
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• 제36권1호
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• pp.37-42
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• 2011

The working mechanism of bisphosphonate on bone cells is unclear despite its powerful inhibitory activity on bone resorption. The differentiation and activation of osteoclasts are essential for bone resorption and are controlled by the stimulatory RANKL and inhibitory OPG molecules. Teeth exhibit a range of movement patterns during their eruption to establish their form and function, which inevitably accompanies peripheral bone resorption. Hence, the mandible, which contains the teeth during their eruption processes, is a good model for revealing the inhibitory mechanism of bisphosphonate upon bone resorption. In the present study, RANKL and OPG expression were examined immunohistochemically in the mandible of rats with developing teeth after alendronate administration (2.5 mg/kg). The preeruptive mandibular first molars at postnatal days 3 to 10 showed the developing stages from bell to crown. No morphological changes in tooth formation were observed after alendronate administration. The number of osteoclasts in the alveolar bone around the developing teeth decreased markedly at postnatal days 3, 7 and 10 compared with the control group. RANKL induced strong positive immunohistochemical reactions in the dental follicles and stromal cells around the mandibular first molar. In particular, many osteoclasts with strongly positive reactions to RANKL appeared above the developing mandibular first molars at postnatal days 3 and 10. Immunohistochemical reactions with RANKL after alendronate administration were weaker than the control groups. However, the immunohistochemical reactivity to OPG was stronger after alendronate administration, at postnatal days 3 and 10. These results suggest that alendronate may decrease bone resorption by regulating the RANKL/OPG pathway in the process of osteoclast formation, resulting in a delay in tooth eruption.