• The korean journal of orthodontics
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• v.24 no.2
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• pp.447-476
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• 1994

This study was performed to evaluate the initial reaction of maxillofacial complex to the Class II intermaxillary and the anterior vertical elastic forces on the six types of archwires including multiloop edgewise arch wires(MEAW). A human dry skull was used for this purpose and this investigation was done by holographic interferometry. Based on such investigation, the fringe pattern and the number of fringes of each condition were compared and analyzed. The findings of this study were as follows: 1. As the orthodontic forces increased, the amount of displacement increased. 2. As the orthodontic forces were applied, the fringes were shown not only in the teeth and the maxilla but also in the adjacent bones, i.e., temporal bone, zygomatic bone, nasal bone, frontal bone and sphenoid bone. And the direction of fringe pattern and the number of fringes were different from each other by the sutures. 3. As the long Class II elastic forces were applied, the backward-downward displacements of the anterior teeth and the maxilla were shown, and backward displacement of the former were grater than those of the latter. And backward displacements were greater by the long Class II elastic forces than by the short Class II elastic forces. 4. As the anterior vertical elastic forces were applied, downward displacements of the anterior teeth and the maxilla were shown, and the downward displacements of the former were greater than those of the latter relatively. 5. The downward displacements of the anterior area to the anterior vertical elastic forces of the MEAW were greater than those of other archwires. In addition, the more tip-back bend was applied, the more displacement was seen. 6. As the Class II intermaxillary forces and the enough anterior vertical elastic forces were applied on the MEAW with tip-back bend, there was an intrusive effect of the posterior teeth.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.109-121
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• 1992

Temporomandibular joint is a major structure to play an important role in the function & stability of the occlusion as well as the stomatognathic system. Therefore, the TMJ is the structure that requires the complete analysis for diagnosing and planning treatment of pathologic changes by TMJ dysfunction and malocclusion. So, in this study, to evaluate TMJ situation in Korean malocclusion, based on the previous accomplishments, students of the dental college of Won-Kwang Univ. are surveyed and selected in terms of Angle's classification of malocclusion, whose TMJ radiographs were taken in the centric occlusion and centric relation. In each maiocclusion groups, the mean and standard deviation of anterior, posterior and superior joint space of the right, left and both side in CO & CR are evaluated and also those of the fossa height and the articular eminence angle of the right, left and both sides are evaluated. The obtained results were as follows: 1. In the correlation coefficient between the malocclusion groups, no other items except the posterior joint space of the right side in CR between in class I and class III are significant. 2. In the correlation coefficient between the right and left side, the each joint space in class I malocclusion group and class II malocclusion group are significant. 3. In the change of each joint space during the transmit from CO to CR, there is a tendency of increasing anterior joint space and decreasing posterior, superior joint spaces in class I, II malocclusion and increasing superior joint space and decreasing anterior, posterior joint space in class III malocclusion, which is significant in the correlation coefficient, but not significant in the T-test. 4. In each malocclusion group, the correlation coefficient between the posterior joint space and the superior joint space in C.R is highly significant. 5. The fossa height of class II malocclusion group is lesser than that of class I or class III, which is not significant in T-test. 6. In the correlation coefficient between Rt. and Lt. side in the fossa height, it is not significant in class I and class III group, but significant in class II malocclusion group. 7. The articular eminence angle of class II malocclusion group is larger then that of class I or class III groups, which is fairly significant. 8. In the correlation coefficient between Rt. and Lt. side in the articular eminence angle, it is significant in each malocclusion group.

• The korean journal of orthodontics
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• v.32 no.4 s.93
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• pp.241-255
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• 2002

This study was performed to evaluate horizontal and vertical characteristics according to lateral cephalometry of adult Korean skeletal Class II patients using a selected horizontal and vortical reference planes of Koreans. 60 males and 60 females consisting of freshman of Yonsei University from 1996 to 1997 and patients with history of orthognatic surgery at the Dental Hospital of Yonsei University with a skeletal Class II profile were chosen and compared with 70 males and 70 females with normal occlusion. The skeletal Class R group had the following conditions : 1. Profile composed of a retrognathic mandible or protrusive maxilla; 2. Class II molar and canine key; 3. ANB-greater than $4^{\circ}; 4$. Wits appraisal-greater than 1.0mm; Cephalometric analysis consisted of 22 skeletal, 25 soft tissue, 12 dental measurements. The results were as follows. 1. There was no considerable vortical measurement difference between the skeletal Class II malocclusion group and the normal occlusion group in skeletal analysis. But, some variations were found between the two groups in soft tissue analysis. 2. Mandibular length of the skeletal Class II malocclusion group was smaller than that of the normal occlusion group. Mandible was more posteriorly positioned in the Class II malocclusion group than in the normal occlusion group. 3. The length and antero-posterior position of the maxilla were not different between the Class II malocclusion and the normal occlusion group. 4. The antero-posterior position of the nose, upper lip and maxillary soft tissue, and nasolabial angle were not different between the two groups. 5. Mandibular soft tissue of the Class H malocclusion group was more posteriorly positioned than that of the normal. 6. The vertical measurements of the incisors(U1-HP, L1-HP) were bigger in the Class II malocclusion group than in the normal, but those of the molars(U6-HP, U6-MP) showed no significant difference between the two groups. 7 Classifying the skeletal Class II malocclusion group according to the antero-posterior position of both jaws, normally positioned maxilla and retruded mandible was 43.3%, both normally positioned maxilla and mandible 28.3%, both retruded maxilla and mandible 20.0%..

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.195-207
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• 2002

Numerous studies have revealed the similarities and discrepancies in two divisions of class II malocclusion, since these malocclusion groups have been postulated to be disparate criterion, much as classified under one diagnostic umbrella. This study was undertaken to describe the craniofacial configurations of class II division 1 and 2, and consequently to discriminate the morphologic differences between the two malocclusion groups in Korean sample. Lateral headfilms of 34 class H division 1 and 29 division 2 were employed, while those of 142 adults of normal occlusion served as a control. The landmarks were digitized and 26 variables were statistically analyzed for one way ANOVA. 1. There manifested no statistically significant difference in maxillary position anteroposteriorly. Normal occlusion group exhibited most anteriorly positioned mandible, whereas class II division 1 showed the most retroposition. Class II division 1 disclosed clockwise rotation tendency of mandible, which resulted in position of the chin Posteriorly. 2. Class II division 1 showed greater in SN to MP, SN to PP significantly than other groups. 3. Class II division 2 showed smaller genial angle and larger mandibular body length than other groups. 4. Class II division 1 revealed greater anterior lower face height than other groups, whereas division 2 dictated significantly greater posterior face height. 5. Class II division 2 expressed the most retroclined lower incisor, while division 1 manifested the most proclination. The largest interincisal angle resided in Class II division 2 group. There were no significant differences in upper molar position anteroposteriorly.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.201-218
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• 1989

This study was focused on the distribution of different facial types of the Class II division I malocclusion groups and skeletal characteristics of the each group and those that anteropsterior relationship of the maxilla and mandible calculated from the analysis of ANB angle and Wits appraisal was quite different from each other, as well. Cephalometric headplates of 140 persons of Class II division 1 malocclusion whose mean age was 11.2 years and 69 persons of normal occlusion whose mean age was 12.2 years were utilize as materials. Measurements were recorded, tabulated and statistically analyzed employing the tracings of the lateral cephalograms, then Class II division 1 malocclusion group was divided into 9 Types according to the angle of SNA and SNB for the anteroposterior relationship of the maxilla and mandible, another 9 Types according to the FH-NPog and SN-MP for the horisontal and vertical relationship, and the other 9 Types according to the ANB and Wits appraisal for intermaxillary relationship as well, with which was based on $Mean{\pm}$ 1SD of those of normal occlusion. The result allowed the following conclusion: 1. $37.1\%$ of population demonstrated maxilla within nounal range and retrognathic mandible to the cranial base, $30\%$ for both maxilla and mandible within normal range, $20\%$ for retrognathic maxilla and mandible and $12.9\%$ of the rest were ananged in Class II division 1 maloccusion groups. 2. Retrognathic mandible and hyperdivergent face accounted for $30.7\%$, mesognathic mandible and neutrodivergent face for $29.3\%$, mesognathic mandible and hyperdivergent face for $16.4\%$, retrognathic mandible and neutrodivergent face for $13.6\%$, mesognathic mandible and hypodivergent face for $10\%$ of population were computed in Class II division 1 malocclusion groups. 3. It was suggested that skeletal Class II malocclusion might be due to anomaly in size and shape of cranial base, underdevelopment of mandible, retropositioning of mandible, underdevelopment of posterior face against anterior face, or any combination of these factors. 4. Population with underdevelopment and / or retropositioning of the mandible showed hyperdivergent tendency of facia profile. 5. The ANB angle and Wits appraisal did not coincide the severity of anteroposterior dysplasia in $35.7\%$ of Class II division 1 malocclusion group each other, and this inconsistency was suggested to be related with mandibular rotation, inclination of cranial base, and anteroposterior position of the maxilla.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.87-100
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• 1995

Distributions and trends were examined in 2155 malocclusion patients who had been examined and diagnosed at Deparment of Orthodontics in Youngdong Severance Hospital over a 10 year-period from 1984 to 1993. The results were as follows ; 1. The number of patients per you had nearly quadrupled during the 10 year-period, with females($58.3\%$) outnumbering males ($41.7\%$). 2. Age distribution had shown 7-12 year-old group being the largest($53.3\%$), but percentages of 7-12 year-old and 13-18 year-old groups had been decreasing while that of above-19 patients had gradually incresed. 3. Distributions in the types of malocclusion according to the Angle's Classification had shown $27.8\%$ for Class I, $22.6\%$ for Class II division 1, $7.9\%$ for Class II division 2, and $41.6\%$ for Class III. Percentages of Class I patients had decreased while percentages of Class II and III patients had increased. 4. Non-extraction cases ($75.4\%$) had outnumbered extraction cases ($24.6\%$), with a general trend toward fewer extraction cases over the 10 year period. 5. Patients who had orthognathic surgery had been increasing, with Class I, II, and III cases comprising $8.8\%,\;16.9\%\;and\;74.3\%$, respectively. There had been three times as newly 2-jaw operations as 1-jaw operations. 6. Nearly $4\%$ of the subjects had facial asymmetries, with Class III cases being the most frequent. 7. Patients with TMD symptoms comprised $4.6\%$, with an increasing trend. The symptoms had occurred more frequently in older patients and in females. 8. Geograpic distributions showed majority (3/4) of patients from the nearby areas, namely Gangnam-gu, Seocho-gu and Songpa-gu.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.233-239
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• 1984

The author studied on the tongue position, tongue space and intermaxillary space at 4 groups; normal occlusion 30 cases, Angle's Class I bimaxillary protrusion 29 cases, Angle's Class II malocclusion 26 cases, Angle's Class III malocclusion 26 cases. This study used the data from cephalometric films of female subject aged from 16 to 23 years. Following results were obtained; 1. Dorsal height in Angle's Class III malocclusion was greater than normal occlusion. 2. Anterior Intermaxillary Height in Angle's Class I bimaxillary protrusion and Angle's Class III malocclusion was greater than normal occlusion. 3. Tongue space in Angle's Class I bimaxillary protrusion was greater than normal occlusion. 4. The ratio of the tongue space to the intermaxillary space (T.S./I.S.) in Angle's Class II malocclusion was greater and the ratio in Angle's Class III malocclusion is lesser than normal occlusion.

• Journal of Chest Surgery
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• v.28 no.2
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• pp.143-149
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• 1995

From January, 1983, to August, 1993, 23 cases of pericardiectomy for chronic constrictive pericarditis were carried out. The 15 male and 8 female patients ranged in age from 7 to 68 years[mean 39.1 years . All patients underwent pericardiectomy through a median sternotomy. Postoperative complications were low cardiac output[2 patients , wound infection[2 patients , pneumonia[2 patients , and unilateral phrenic nerve palsy[2 patients . One patient died of low cardiac output 1 day after pericardiectomy due to the associated transposition of great artery and hypoplastic right lung. Clinical and pathological findings showed that the cause of constrictive pericarditis was tuberculous in 8 cases[34.8% , idiopathic in 12 cases[52.2% and pyogenic in 3 cases[13.0% . Central venous pressure fell below 10cmH2O by immediate in 6 cases, fell below 10cmH2O by 24hrs in 5 cases and continued above 10cmH2O after 24hrs in 12 cases. Preoperative NYHA functional class of patients showed class I-1, classII-4, class III-14, and class IV-3. Postoperativly NYHA functional class was improved to class I-15, classII-6, class III-1.

• Imaging Science in Dentistry
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• v.52 no.1
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• pp.75-82
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• 2022

Purpose: This cross-sectional study evaluated and categorized the tomographic sagittal root position (SRP) of the maxillary anterior teeth in a Brazilian population. Materials and Methods: Cone-beam computed tomographic scans of 420 maxillary anterior teeth of 70 patients (35 men and 35 women, mean age 25.2±5.9 years) were evaluated. The SRP was classified as class I, II, III, or IV. In class I, the root is positioned against the buccal cortical plate; in class II, the root is centered in the middle of the alveolar housing; in class III, the root is positioned against the palatal cortical plate; and in class IV, at least two-thirds of the root engage both the buccal and palatal cortical plates. Results: In total, 274 teeth (65.2%) were class I, 39 (9.3%) were class II, 3 (0.7%) were class III, and 104 (24.8%) were class IV. The frequency distribution over the teeth groups was different from the overall analysis. Important differences were found in the frequencies of classes I, II, and IV compared to other populations. Sex was not associated with the SRP classes (P=0.307). Age distribution was significantly different over the classes (P=0.004). Conclusion: The findings of this study on the distribution of SRP classes among the Brazilian population compared to other populations demonstrate that the SRP should be analyzed on a case-by-case basis for an accurate treatment plan in the maxillary anterior area.

• Journal of the Korean earth science society
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• v.43 no.4
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• pp.557-566
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• 2022

The purpose of this study was to examine the status of the field application of the Science II career electives with the application of the 2015 revised curriculum up to the 3rd year of high school. This study focused on examining high school science teachers' perceptions of the student-participatory class and process-centered assessment in Science II subjects, which are career-intensive high school science electives. A total of 192 science teachers responded to the survey questionnaire, and 12 teachers participated in interviews. In the in-depth interviews conducted to supplement the survey results, questions were asked about changes in the overall class, the status of student-participatory classes, and changes in the assessment of Science II subjects due to the emphasis on process-centered assessment. The main research results included teachers' perceptions of changes in teaching and assessment methods with the application of the revised curriculum, the degree to which the eight skills used in Science II classes develop the key competencies of science, and the teaching and assessment methods commonly used in Science II classes. Science teachers generally agreed with the purpose and necessity of introducing student-participatory classes and process-centered assessment, which are the core purpose of the 2015 revised curriculum. However, they had difficulties in practice due to the excessive content of Science II subjects. Problems were also encountered with securing objectivity and fairness during assessments and the operation of online science classes due to COVID-19.