• 대한치과교정학회지
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• 제47권5호
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• pp.277-288
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• 2017

Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

• 치과방사선
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• 제21권2호
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• pp.203-220
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• 1991

The purpose of this study was to investigate the changes of morphology and structure of bone tissue, caused by administration of high-dose hydrocortisone, elcatonin and cyclophosphamide. In order to carry out experiment, 60 four-week old Sprague-Dawley strain rats weighing about 107 gms were selected and divided into experimental group and control group. The experimental group was subdivided into three groups, assigned fifteen rats for each group, by the different drugs administered. Each experimental group was then categorized as follows: hydrocortisone 30㎎/㎏ b.w. with daily subcutaneous injection, elcatonin 20U/㎏ b.w. with daily subcutaneous injection, and cyclophosphamide 100㎎/㎏ b.w. with a single intraperitoneal injection. Fifteen rats were injected daily with 5㎖/㎏ b.w. of normal saline solution subcutaneously in control group. Rats in control group and experimental group were serially sacrificed on the 6th, the 15th and the 22nd day after injection of normal saline, hydrocortisone, elcatonin and cyclophosphamide, respectively. Being sacrificed, both sides of mandibular condyles were removed and fixed with 10% neutral formaline. The one side of mandibular condyles was radiographed with soft X-ray apparatus. Thereafter, the obtained radiographs were observed, and the bone density of condylar head and condylar neck regions was measured by use of transferring video-based digital radiograph. The other side was further decalcified and embedded in paraffin as usual manner, then sectioned and stained with hematoxylin and eosin, observed by light microscope. The obtained results were as follows: 1. Sclerotic changes with regularly increased trabecular pattern were seen throughout experimental periods in hydrocortisone group. Increased the number of trabecular pattern with irregularity and periodic striation on the periphery of condylar head region were appeared with lapse of time in elcatonin group. In cyclophosphamide group, irregular trabecular pattern and stippled radiopacities on mandibular condyle were observed with lapse of time. 2. The bone density of condylar head region was increased in hydrocortisone group, decreased in elcatonin group, and tended to be decreased in cyclophosphamide group, compared with that of control group according to the experimental periods. 3. The bone density of condylar neck region tended to be rather increased in hydrocortisone group, elcatonin group and cyclophosphamide group, depending on the experimental periods. 4. In microscopic studies, there were irregular trabecular bonds and osteoblastic activity in hydrocortisone group and elcatonin group throughout experimental periods, degenerative cartilage and trabecular bones in the 6th day and densely calcified trabecular bones in the 22nd day in cyclophosphamide group.

• 대한치과교정학회지
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• 제30권3호
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• pp.297-306
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• 2000

최대 개구운동시 하악골의 개구능력과 과두의 활주 운동 양상을 관찰하고 두개안면골격 형태요소와의 상관성을 알아보기 위해 경희의료원 교정과에 내원한 10세 전후의 아동 68명의 최대감합위 및 최대개구위 측모두부방사선사진을 분석하고 통계 처리하여 다음과 같은 결론을 얻었다. 1. 최대개구량의 평균치는 47.1mm, 최대개구운동시 과두의 이동 직선거리는 18.1mm, 과두의 수평 이동거리는 17.5mm, 수직이동거리는 3.8mm였으며 이동경사도는 $13.1^{\circ}$이었다. 2. 전방두개저의 길이, 하악골 및 상악복합체의 전후방적인 길이가 길수록, 하악상행지가 전방으로 경사할수록, 후안면 고경이 크고 하악의 경사도가 작을수록 개구량이 컸다. 3. 하악상행지가 직립된 경사도를 가질수록, 하악골의 만곡도가 클수록 과두는 수직적인 활주운동을 하였다. 4. 상악복합체가 전후방적으로 길수록 과두는 전방으로 길게 활주운동을 하였다. 이상의 내용으로 볼 때 최대개구위 측모두부방사선사진은 부정교합 환자의 개구운동시 하악골의 운동양상을 평가할 수 있는 진단 자료로서 유용하며 하악골의 개구운동 양상은 두개안면골격의 특정한 형태적 요소와 연관성을 가지며 악관절의 기능적 해부 형태에 관한 정보를 제공하는 것으로 사료된다.

• 대한치과교정학회지
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• 제24권2호
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• pp.275-294
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• 1994

The occlusal interference during adolescent period makes some effects on growth and development and morphological changes. And so, if we could predict the the timing and results of orthodontic treatment who have occlusal interference during adolescent period, it may be helpful for diagnosis and treatment planning of orthodontic treatment. For about those, the purpose of this study was to evaluate the effects of the posterolateral displacement by the metal casting crown with inclined pathway on the mandibular condyle and morphologic changes of mandible in the rat. The experimental animals were thirty six Sprague-Dawley male rats of 8 weeks old. Eight of them was used as control group, and experimental group 1 ( continuous appliance wearing group ) was composed of sixteen and experimental group 2 ( appliance removal group after worn the appliances during 3 months ) was composed of remaining twelve. The animals of experimental grouop 1 were sacrificed after 1, 2, 3, 6 months from beginning of the experiment and experimental group 2 were sacrificed 1, 2, 3 months after removal of the appliance from worn the appliance during 3 months. Both of mandible and temporomandibular joint were observed histologically and radiologically. The results were as follows : 1. In experimental group 1, the mandibular length and lower posterior height were decreased with experimental period, while the lower anterior height was increased, and the curvature of lower incisors and lingual inclination of anterior alveolar bone were profound as compared with control group. 2. In experimental group 1, both of the thickness of the condylar cartilage were thinned in the posterosuperior region, and this phenomenon was more prominent on right than left in 3-Mo experimental period and both sides were marked thinned in 6-Mo experimental period. 3. In experimental group 2, the lower anterior height was low and lower posterior height was high as compared with experimental group 1, and the curvature of lower incisors and lingual inclination of anterior alveolar bone were recovered to control group. 4. In experimental group 2, both of the thickness of the condylar cartilage were thickened in the posterosuperior region, and this phenomenon was more prominent with experimental period. 5. In experimental group 2, the mandibular length was short, lower anterior height was hight, the curvature of lower incisors were profound, and in histologically, both of the thickness of the condylar cartilage were thickened in the posterosuperior region as compared with control group. As shown above, the occlusal interfemce affected the condylar cartilage, curvature of lower incisor, inclination of anterior alveolar bone, mandibular length, and anterior and posterior height. When the interference was removed, significant recover was found in condylar cartilage, mandibular length, and posterior height. Although no significance was found, other items of measurement showed trends for recovery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권5호
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• pp.446-454
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• 2000

Condylar process of mandible is an important and fuctionally versatile part of the mandible. There were quite large amount of investigations on the functional and anatomical adaptation of the temporomandibular joint(TMJ) to the surrounding tissues. But controversies on the mechanism of functional adaptation of the joint still exist. In this research, we investigated changes in the TMJ by the lateral deviation of the maxillary incisor to shift the mandible right, and bone the undecalcified microscopic sections with fluorescent microscope and von Kossa staining with bright field microscope. Results were as follows: 1. Lateral deviation rendered shifting and tilting of the mandible, There were, compressions in the right joint and opening of the left joint space at early stage. At the same time, both condyles shifted slightly to anterior. 2. After $2{\sim}4$ weeks, left condyle showed anterior displacement and compressions in the joint space. Right condyle showed only slight shift to the anterior. 3. Regardless of the direction of the lateral shift, anterior bite plate compressed both condyle heads until 2 weeks. 4. There are bone resorptions in the anterior aspect of the condyle head and apposition of posterior border. Bone remodeling were observed between 3 and 4 weeks. 5. After 8 weeks of the experiment, there were little differences in condylar morphology between experimental and control group, though slight shifting and compression were still present in the experimental group. Lateral deviation of mandible evoked active remodeling of the TMJ until functional and anatomical reconstruction of TMJ position was achieved.

• Journal of Oral Medicine and Pain
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• 제17권2호
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• pp.63-73
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• 1992

This study was performed for the purpose of investigating the relation between width of temporomandibular joint space and craniofacial morphology in patients with CMDs. The subjects utilized here were aged from 16 to 63 years old and 19 male and 46 female. For the study, each patient was taken radiographs by Transcranial and Lateral Cephalographic projection and the films were traced with routine method. The measured items were anterior, superior, posterior joint space and relative condylar position to the deepest part of glenoid fossa in Transcranial film and items related vertical and/or horizontal growth in Cephalogram. The data were processed with SPSS/PC+ package for statistical analysis. The obtained results were as follows : 1. Anterior joint space in affected side were wider than that of unaffected side, but for superior and posterior joint space, the value of unaffected side were more than those of affected side. 2. Superior or posterior joint space of affected side were significantly correlated with items related vertical growth, such as ramus height, Jarabak ratio, FMA. From this, the following cold be proposed, the wider the joint space of superior or posterior aspect of affected side was, the more the patient showed growth pattern of counter clockwise. 3. Superior or posterior joint space of affected side were significantly correlated with items related horizontal growth, such as SNPo, NAPo, APDI and ANB. From this the following could be proposed, the wider the joint space of superior or posterior aspect of affected side was, the more the patient showed anterior displacement of mandible. 4. It would be proposed that the diagnositic value of superior and posterior joint space of affected side in transcranial radiograph was excellent.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권5호
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• pp.423-427
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• 2001

Objective: This study was prepared to figure out a certain dimension and morphology of the condyle at the central, medial and lateral aspects on MR images of asymptomatic volunteers, which could be comparable with those of the TMD patients' condyle. Materials: Sixty TMJs from 30 asymptomatic volunteers(15 male, 15 female) who had no clinical symptoms and no disc displacement on sagital and coronal view of MRI were served as normal. Method: MR images were taken from the asymptomatic volunteers and the dimension of the anteroposterior length, mediolateral width, height, convexities were measured through the images on the sagittal and coronal sections of mandibular condyle. Then, these data were collected and analyzed. Result: The mean value of anteroposterior length was $8.00{\pm}1.21mm$ at central section and mediolateral length was $21.40{\pm}2.32mm$ on coronal view. The anterior condylar length at medial side was the shortest and the convexity of anterior slop at the lateral side was proved to be the flattest among 3 sections. There were little dimensional and morphological differences at sagittal sections, but the mediolateral width of condyle at coronal section was significantly different between male and female. Conclusion: In sagittal sections, the anterior condyle length was shortest at medial side and the convexity of anterior slop was flattest at lateral side, and there were little dimensional and morphologic differences between male and female. In coronal section, male's condyle was more wider and flatter than female's.

• 대한치과교정학회지
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• 제41권2호
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• pp.87-97
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• 2011

안면비대칭의 원인은 다양하며, 비대칭적 성장은 상악골과 하악골의 길이나 각도로 평가되어지곤 한다. 하지만 하악 과두의 비대칭적인 위치나 형태 또한 비대칭의 표현에 영향을 줄 것으로 생각된다. 따라서 본 연구는 하악 과두가 안면비대칭의 표현형인 이부 편위에 영향을 주는지에 대해 알아보고자 하였다. 50명의 골격성 III급 부정교합자 중 4 mm 이상의 menton point deviation을 보이는 비대칭군 30명, 4 mm 이하의 menton point deviation을 보이며 뚜렷한 안면비대칭이 없는 20명을 대칭군으로 하여, 두개저에 대한 좌우 하악 과두의 근원심적, 전후방적 위치를 평가하고, axial 평면에서 장축을 설정해 하악 과두의 최대 크기와 coronal plane에 대한 각도를 평가하였으며, sigmoid notch 상방 하악 과두의 길이와 부피를 측정하였다. 대칭군은 좌우 하악 과두의 위치, 각도, 크기, 길이, 부피에 있어 통계적인 차이가 없었다. 비대칭군은 이부 편위측과 비편위측으로 나누어볼 때, 이부 편위에 따른 좌우 하악 과두의 위치와 angulation 에서 통계적 차이는 없었으나, 하악 과두의 크기, 길이 및 부피에서는 비편위측 값이 컸고, 이부 편위량이 클수록 좌우 크기, 길이의 차이 및 편위측에 대한 비편위측 하악 과두의 부피비가 컸다. 또한 편위측에 대한 비편위측 하악 과두의 부피비가 이부 편위의 정도를 가장 잘 설명해주는 특성이었다. 이상의 결과를 통해 하악 과두의 비대칭이 안면비대칭의 발현에 영향을 주며, 비편위측 하악 과두가 편위측에 비해 크고 길다는 것을 알 수 있었다.

• 대한치과교정학회지
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• 제43권4호
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• pp.168-177
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• 2013

Objective: In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Methods: Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. Results: For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal inclination, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the differences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. Conclusions: UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance.

• 대한소아치과학회지
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• 제23권2호
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• pp.559-574
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• 1996

The purpose of this study was to determine whether there was any correlation between temporomandibular joint dysfunction and structure of the mandibular condyle. Weanling rats had their masseter muscles resected and immunohistochemical findings were observed with a light microscope. The results obtained were as follows : 1. The condylar cartilage region was divided into articular, proliferating, cartilage cell and hypertrophic cell layers according to cell morphology. 2. In light microscopic views, the proliferating and cartilage cell layers of the experimental group decreased gradually and at the 8th week significantly. 3. In immunohistochemical staining for type I and II collagen, a reaction was detected in the lower part of proliferating cell and cartilage cell layers. In the cartilage cell layers, a stronger cellular reaction was present. Immunohistochemical staining for type II collagen reacted more strongly than that of type I collagen. 4. In immunohistochemical staining for proteoglycan, the staining of the experimental group resembled the control group and gradually showed a weak reaction. The proliferating and cartilage cell layers reacted more strongly than the hypertrophic cell layer. 5. In immunohistochemical staining for proliferating cell nuclear antigen(PCNA), the strong reaction was detected in the nucleus of the proliferating cell layer both in control and experimental groups. But the thickness of the proliferating layer decreased in experimental group, consequently the reaction of the experimental group was reduced more than that of the control group.