• 대한치과교정학회지
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• 제29권2호
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• pp.197-207
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• 1999

심한 골격성 부조화를 보이는 환자에서 치열 보상에 의하여 교합 접촉이 양호하게 유지되는 경우를 자주 볼수 있으며, 이러한 치열 보상은 삼차원 평면 모두에서 발생한다. 본 연구에서는 개방교합성 골격 형태의 치 보상 양상을 관찰하고, 이러한 골격형태를 보이는 성인과 아동의 치열보상 양상의 차이를 비교하고자 하였다. 개방교합성 골격형태를 보이는 환자 60명과 정상군 60명을 대상으로 하였으며 이들 각각을 연령에 따라 8-12세의 아동군과 17세 이상의 성인군으로 분류하여 다음과 같은 결론을 얻었다. 1. 개교성골격군의 후하안면고경은 아동과 성인 모두에서 정상군보다 작으며(p<0.01), 전하안면고경은 아동에서 정상군과 차이가 없으나 성인에서는 정상군보다 크다(p<0.01). 2. 개교성골격군에서 기저골 길이에 대한 상하악 전치의 맹출비는 아동기에 정상군보다 크며(p<0.05), 성인기의 상악전치의 맹출비는 아동기에 비해 컸으나(p<0.05) 하악 전치의 맹출비는 아동기와 유사하였다. 3. 개교성골격군에서 상$\cdot$하악 구치의 기저골의 길이에 대한 상대적인 맹출량은 아동기에 정상군과 차이가 없었지만, 성인에서 상악 구치의 상대적인 맹출량은 정상군보다 컸으며 (p<0.01), 하악 구치의 상대적인 맹출량은 정상군과 동일하였다. 4. 개교성골격군에서 하악평면에 대한 하악 교합평면의 경사는 아동이나 성인 모두에서 정상군보다 더 큰 각을 이루며 (p<0.01), 상악 교합평면 경사는 성인기에 아동기보다 컸다(p<0.05). 상악 교합평면은 성인기에 아동기보다 전상방경사를 보였다(p<0.01). 5. 개교성골격군에서의 치성보상은 아동기에 이미 상$\cdot$하악 전치부의 과맹출에 의하여 이루어진다. 개교성골격군은 성장과정중 상악 구치부의 과도한 수직적 발육을 보이며 이에 대한 보상적 반응으로 상$\cdot$하악 전치부는 정상군보다 더 큰 맹출량을 보이는데 특히 상악 전치부에서 더 큰 맹출비를 보인다.

• 대한치과교정학회지
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• 제34권3호
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• pp.219-227
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• 2004

본 연구의 목적은 치아의 이동양상을 관찰하기 위해 고안된 Calorific machine system(typodont simulation system)과 precision TPA를 이용하여, 근심 회전된 (mesial-in rotation) 상악 대구치를 회전 (derotation)시킨 후 해당 치아 및 반대측 고정 원의 공간변화를 확인하기 위함이다. 우측 상악 제 1대구치를 고정원으로 사용하였고 좌측 상악 제 1대구치를 근심 회전된 치아로 사용하였으며, TPA에 부여한 회전각은 $20^{\circ},\;40^{\circ},\;60^{\circ}$였다. 먼저 수동형의 precision TPA를 제작한 후, TPA의 왼쪽 삽입부위(tag)를 각각 $20^{\circ},\;40^{\circ},\;60^{\circ}$로 구부려 실험하였다. 각 군별 실험은 동일한 조건에서 5회 반복한 후 ANOVA와 Tucky's Studentized Range (HSD) test로 검정 하였다. 실험 결과, 교합면에서는 precision TPA의 구부리는 각도가 증가할수록 회전된 구치의 원심 설측 교두가 근심 설측 방향으로 움직이는 동안, 근심 협측 교두는 협측으로 더 많이 움직였고(p<0.001) 원심방향으로는 더 적게 움직였다. (p<0.001) 시상면에서 회전 구치의 구개측 치근은 더욱 근심으로 움직였다. (p<0.001) 횡단면에서는 회전된 치아가 약간의 정출을 보였다(p<0.001). 고정원으로 사용된 우측 상악 제1대구치는 세 평면에서 의미 있는 변화를 보이지 않았다.

• 대한치과교정학회지
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• 제16권1호
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• pp.85-106
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• 1986

The purpose of this investigation was to know the means of the T.M.J. space and to compare spational differences in centric relation and centric occlusion by the T.M.J. Tomogram and to study the correlation between the articular eminence slope and the lingual surface slope of the maxillary central incisor by the Cephalogram in near normal occlusion subjects. These results could give contribution for the diagnosis of orthodontic treatment and T.M.J. dysfunction and the assessment of orthopedic treatment and orthognathic surgery. 44 young adults (28 men and 16 women, 21 to 27 years of age) were selected from the Dental students in Yonsei Univ. Criteria for selection was normal occlusion, no clinical signs and T.M.J. dysfunction, no history of orthodontic treatment, and no missing tooth. After submental vertex view analysis. each subject was given the T.M.J. Tomogram in centric relation and centric occlusion and the Cephalogram was given with Quint Sectograph. All data was recorded and statistically processed with the CYBER computer system. Results were analyzed: the following findings and conclusions were derived. 1. The mean value for the combined right and left anterior joint space was 2.549mm, the posterior space was 2.260mm, and superior space was 3.31mm in centric relation. The anterior space was 2.316mm, posterior space was 2.474mm, and superior space was 3.435mm in centric occlusion. 2. In the centric relation position, both condyles were placed more posterioly and superioly in their fossae than in the centric occlusion position by the spatial difference. 3. In the centric occlusion position, both condyles were more symmetrically placed in their fossae with equal anterior-posterioly rather than in the centric relation position. 4. The mean articular eminence angle was $48.19^{\circ}$ and the mean fossa height was 7.911mm. A strong positive correlation between the articular eminence angle and fossa height in T.M.J. Tomogram was found. 5. In Cephalometric analysis, there was a strong positive correlation between the articular eminence slope and the lingual surface slope of the upper central incisor to the FH plane, occlusal plane, and S-N plane. 6. There was moderate positive correlation between the S-E measurements and the fossa height, articular eminence angle, and DcGn < F-H.

• 대한치과교정학회지
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• 제30권5호
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• pp.521-533
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• 2000

본 연구의 목적은 피개교합 양상에 따른 성인 I급 부정교합자의 골격적 특징과 수직부조화를 야기하는 치성 및 골격성 요인들을 분석하기 위한 것이다. 서울대학교 치과대학 교정학교실에 소장되어 있는 정상교합군 표본 중 40명을 정상교합군, 서울대학교병원 교정과에 내원하여 I급 부정교합으로 진단받은 성인 환자중 전치부 수직피개량이 -0.1mm 이하인 40명을 개방교합군, 4.0mm 이상인 40명을 과개교합군으로 선정하여 측모 두부 X-선 계측사진을 촬영하였다. 46개의 계측항목을 선정하고 SPSS program을 이용하여 각 군별 ANOVA, 판별분석, 다중회귀분석을 시행하여 다음과 같은 결론을 얻었다. 1. 주로 하악골 형태와 하안면부의 치성, 골격성 요인이 수직부조화의 양상에 많은 영향을 끼쳤다. 2. 개방교합군의 수직부조화 양상은 하안면부에서 두드러지게 나타났으며 하악골 형태와 하악하연평면 경사도와 관련이 있었고, 판별분석 결과 골격적 요인의 기여도가 높았다. 3. 과개교합자의 수직부조화에는 주로 curve of Spee, 상악구치의 수직고경 등 치성 요인들의 기여도가 높았으며, 골격적 요인으로는 articular angle의 기여도가 높았다. 4. 다중회귀분석 결과 I급 구치관계를 갖는 성인에서 overbite의 결정요인에는 주로 하악전치와 교합평면각, curve of Spee, 절치간 각도 등의 치성요인이 기여하였다.

• Journal of Oral Medicine and Pain
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• 제31권4호
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• pp.337-346
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• 2006

이 논문은 2년 동안 경북대학병원 구강내과를 턱관절 질환을 주소로 내원한 환자 중에 과두흡수가 있는 환자들로서 자기공명영상, 파노라마, 측방횡두개상 그리고 측방 두부방사선 사진들을 모두 촬영한 34명의 환자들만 선택하여, 측방두부방사선 계측으로 과두흡수와 안면부 골격형태의 연관성을 한국인 정상 교합자들의 평균치와 비교 조사하였고, 전치부 개교합이 동반된 군과 개교합이 없는 군을 서로 비교하였으며, 또한 자기공명영상으로 과두흡수와 관절원판변위와의 관련성을 조사한 결과 과두흡수가 잘 발생될 수 있는 환자들은 다음과 같은 특징을 가졌다: (1) 34명중 1명만이 남자로 여자가 대부분이었다, (2) 연령대는 어느 연령에서나 발생가능하나 10대와 20대에서 발병률이 높았다, (3) 환자들은 높은 하악하연각과 높은 하악각을 가졌다. (4) 하악지의 높이는 작게 나타났으며, (5) 전악각 함요(antegonial notch)가 대체적으로 저명하였다, (6) 구치부 교합은 Angle's Class I 관계가 많았으나, ANB각도는 평균 5.54도로 하악의 후퇴를 나타내었다. (7) 과두흡수는 하악하연각이 낮은 경우에는 거의 발생하지 않았다, (8) 통계학적 유의한 차이는 없었으나 개교합이 동반된 군이 개교합이 없는 군보다 hyperdivergent한 골격형태를 가졌다, (9) 자기공명영상사진에서 과두흡수는 대부분 비정복성 관절원판전위와 연관되어 있었다. 수직적 골격성장이 큰 경우 관절원판 전방변위와 과두흡수의 원인이 될 수 있으리라 생각된다.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.434-439
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• 2013

PURPOSE. The aim of the present study was to evaluate the effects of posts with different morphologies on stress distribution in an endodontically treated mandibular premolar by using finite element models (FEMs). MATERIALS AND METHODS. A mandibular premolar was modeled using the ANSYS software program. Two models were created to represent circular and oval fiber posts in this tooth model. An oblique force of 300 N was applied at an angle of $45^{\circ}$ to the occlusal plane and oriented toward the buccal side. von Mises stress was measured in three regions each for oval and circular fiber posts. RESULTS. FEM analysis showed that the von Mises stress of the circular fiber post (426.81 MPa) was greater than that of the oval fiber post (346.34 MPa). The maximum distribution of von Mises stress was in the luting agent in both groups. Additionally, von Mises stresses accumulated in the coronal third of root dentin, close to the post space in both groups. CONCLUSION. Oval fiber posts are preferable to circular fiber posts in oval-shaped canals given the stress distribution at the postdentin interface.

• 치과방사선
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• 제12권1호
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• pp.57-61
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• 1982

The author has made a study on the classification of the mandibular 3rd molars of Korean youths through dental radiography by means of Pell & Gregory's classification and on the prevalence of the dental caries of distal surface of the mandibular 2nd molar adjacent to the mandibular 3rd molars turned anteriorly. The results are as follow; 1. It was found that the largest case number was class I (272 cases, 52.9%) in the relation of the tooth to the ramus of the mandible and 2nd molar. 2. The mesio-angular position was the largest number (239 cases, 46.5%) in the relation of the long axis of the impacted mandibular 3rd molar to the long axis of the 2nd molar. 3. The mesio-angular position of class I was the largest number (140 cases, 27.2 %) in the relation of the tooth to the ramus of the mandible and 2nd molar and the long axis of the impacted mandibular 3rd molar to the long axis of the 2nd molar. 4. The average angle of the long axis of mandibular 3rd molar in mesioangular position or horizontal position to the occlusal plane was 143° 5. Mandibular 3rd molar with lesion such as dental caries or pericoronitis was 73 cases (14.2). 6. The caries incidence rate of the distal surface of the 2nd molar was about 3.1%.

• 대한치과교정학회지
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• 제23권3호
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• pp.359-374
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• 1993

At present, many orthodontists regard the root parallelism of the posterior teeth important not only in diagnosis and treatment planning but also for predicting posttreatment stability. To evaluate it, they usually refer to the orthopantomogram. At this study, 97 samples were collected from students of Yonsei University, who have well-proportioned face, Angle's class I canine & molar relationships and no crown axis deviation of the posterior teeth including canines. Reliability of the root parallelism observed from orthopantomogram was evaluated by comparison with $45^{\circ}$ oblique cephalogram. The results were as follows : 1. In comparing the differences between anglular measurements in $45^{\circ}$ oblique cephalogram & orthopantomogram with $5^{\circ}$, those to mandibular plane were significantly less than to occlusal plane in number of items which showed less differences than $5^{\circ}$. 2. Compared the root parallelisms in the orthopantomogram with those in $45^{\circ}$ oblique cephalogram with $1\%$ significance level, parallelism between upper canine & 1st premolar, lower canine & 1st premolar, lower 1st premolar & 2nd premolar, and lower right 2nd molar & 3rd molar showed statistically significant differences. 3. When the significance between the differences of the root parallelism between above two kinds of film and $5^{\circ}$ was verified by two sided paired t-test, more or less large difference was shown between lower right 2nd molar & 3rd molar, a little larger than $5^{\circ}$ between lower canine & 1st premolar, smaller at the rest of them. 4. In $45^{\circ}$ oblique cephalogram, lower canine & 1st premolar showed convergent root arrangements each other, while in orthopantomogram they were divergent each other. All the others except them showed convergency on the upper, divergency on the lower in both films.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권4호
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• pp.345-352
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• 1999

This study was conducted for the purpose of suggestion of the new technique of sagittal split ramus osteotomy pararell to the true sagittal plane. This pararellism is the important concept of the sagittal split ramus osteotomy to reduce the condylar sagging including mandibular hypomobility, temporomandibular disorder, occlusal relapse and other complications. We used 26 adult dry manibles(52 rami), and obtained the computed tomographs through the sagittal, horizontal and coronal sections. The results were obtained as follows. 1. On sagittal section, mean area of S1 was $8.63{\pm}2.10cm^2$, S2 was $8.93{\pm}1.94cm^2$, S3 was $9.49{\pm}2.15cm^2$, S6 was $10.72{\pm}2.22cm^2$. The wider area of sagittal section, the more lateral section, But, no significant differency between the areas of the sagittal sections(P>0.05). 2. On horizontal section, The distance between the inferior alveolar canal and the lateral cortical plate of the mandibular ramus were $6.73{\pm}1.24mm$ minum, $7.70{\pm}1.44mm$ maximum. 3. On coronal section, Outer mandibular angle were $4.84{\pm}2.37^{\circ}$ right side, $4.93{\pm}2.12^{\circ}$ left side. 4. The design of the ideal true sagittal split ramus osteotomy is that posterior border of osteotomy must be limited vertically, at the right posterior point of lingula mandibularis and anterior of osteotomy must be extended to mandibular body, anteroinferiorly.

• 대한치과교정학회지
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• 제53권2호
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• pp.125-136
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• 2023

Before progress was recently made in the application of temporary anchorage devices (TADs) in bio-mechanical design, orthodontists were rarely able to intrude molars to reduce upper posterior dental height (UPDH). However, TADs are now widely used to intrude molars to flatten the occlusal plane or induce counterclockwise rotation of the mandible. Previous studies involving clinical or animal histological evaluation on changes in periodontal conditions after molar intrusion have been reported, however, studies involving human histology are scarce. This case was a Class I malocclusion with a high mandibular plane angle. Upper molar intrusion with TADs was performed to reduce UPDH, which led to counterclockwise rotation of the mandible. After 5 months of upper molar intrusion, shortened clinical crowns were noticed, which caused difficulties in oral hygiene and hindered orthodontic tooth movement. The mid-treatment cone-beam computed tomography revealed redundant bone physically interfering with buccal attachment and osseous resective surgeries were followed. During the surgeries, bilateral mini screws were removed and bulging alveolar bone and gingiva were harvested for biopsy. Histological examination revealed bacterial colonies at the bottom of the sulcus. Infiltration of chronic inflammatory cells underneath the non-keratinized sulcular epithelium was noted, with abundant capillaries being filled with red blood cells. Proximal alveolar bone facing the bottom of the gingival sulcus exhibited active bone remodeling and woven bone formation with plump osteocytes in the lacunae. On the other hand, buccal alveolar bone exhibited lamination, indicating slow bone turnover in the lateral region.