• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.210-219
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• 2017

This study aimed to investigate the prevalence and distribution of enamel hypomineralization, including molar-incisor hypomineralization (MIH), among adolescents and assess their correlation with esthetic satisfaction. A total of 1371 adolescents between the ages of 14 and 16 years in Yangsan city were evaluated for enamel hypomineralization, including MIH, according to the European Academy of Paediatric Dentistry (EAPD) criteria. In a parallel survey, esthetic satisfaction about anterior teeth and its correlation with incisor enamel hypomineralization were analyzed. The prevalence of MIH was 13.8% (n = 189), while that of hypomineralization in any permanent tooth was 23.2% (n = 318), which was substantially greater compared to the national prevalence of MIH. Mandibular first molars exhibited the highest prevalence of hypomineralization, followed by maxillary central incisors and mandibular second molars. Among anterior teeth, the most frequently affected site was the incisal edge of maxillary central incisors. A high degree of hypomineralization in anterior teeth was associated with a high demand for esthetic treatment.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.475-483
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• 2003

The purpose of this study is to evaluate hard and soft tissue changes following the subapical osteotomy in bimaxillary dentoalveolar protrusion patients requiring maximal retraction adult female patients was selected. Surgical procedures were performed by the same surgeon, anterior subapical osteotomy techniques were employed on the maxilla and cephalometric radiograms were traced and superimposed using the best-fit method and two reference The results were as follows 1. The bodily movement of the maxillary anterior segment was achieved in a posterior moved posteriorly with a slight correction of the lower incisors. 2. The horizontal soft tissue measurements changed significantly after treatment, but Nt and Sn vertical soft tissue measurements indicated that Ls moved inferiorly and Li superiorly. 3. The correlation between hard and soft tissue changes indicated that ${\Delta}HId/{\Delta}HLi,\;{\Delta}HId/{\Delta}LL-Eline,\;{\Delta}Hpt.B/{\Delta}HILS,\;and\;{\Delta}UI-FH/{\Delta}NL$ were significant. 4. More lower lip relative to upper lip retraction was demonstrated in relation to Rickett's E-line. The ratio between upper lip displacement was $50\%$, and between the lower incisor and lower lip displacement was $60\%$. We conclude from the results that the anterior subapical osteotomy is an efficient treatment severe dentoalveolar protrusion and desire rapid results.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.652-661
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• 2008

The purpose of this study was to evaluate the skeletal and dental effects obtained by the Frankel functional regulator III in growing children with Class III malocclusions. Cephalometric changes in thirty children at the time of mixed dentition malocclusions (initial mean age, $7.9{\pm}1.1$ years; mean treatment duration, $1.5{\pm}0.8$ years) were analysed. The results were as follows : 1. The skeletal effects on the maxilla showed a significant downward displacement whereas forward displacement was not significant in comparison with the control group. 2. The skeletal effects on the mandible showed statistically significant backward and downward displacement. 3. The dental effects showed statistically significant backward movement in the mandibular incisor tip and increase of overjet The results suggested that forward displacement on the maxilla was insufficient and treatment effects were caused mainly by downward displacement of the maxilla, backward and downward rotation of the mandible, and the increase of overjet during short period.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.380-393
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• 2004

The Purpose of this study was to investigate the dentoalveolar compensation according to anteroposterior skeletal discrepancy in normal occlusion and to evaluate cephalometric parameters that quantitatively describe dental compensations. The study consisted of 90 subjects (50 males. 40 females) who were selected among specimens of normal occlusion at Seoul National, University Dental Hospital, Dept. of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized for each subject. According to the anteroposterior skeletal pattern the sample was divided into three groups. Cephalometric data were analyzed for the three groups using the SPSS program. Independent t-test, correlation analysis and regression analysis were carried out. The results were as fellows: Dentoalveolar compensation was found in upper and lower incisor inclination and occlusal plane inclination. As the mandible located anterior to the maxilla, the maxillary incisors incisors more labially. the mandibular incisors more lingually, and the occlusal plane continued to flatten. The dental parameters most correlated with anteroposterior skeletal discrepancy were L1 to SN and L1 to FH. Among the compensatory dentoalveolar changes, lower incisor inclination was strongly related to the anteroposterior jaw relationship and played au imposrtant role in obtaining a normal incisor relationship U1 to PtGn and L1 to APog were constant irrelevant to anteroposterior skeletal discrepancy.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.255-263
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• 2006

Objectives: This article reported three patients developed anterior open bite seemed to be related to TMJ anterior disc dislocation without reduction(ADD WO R), but no evidence of condylar destructive or collapse and analyzed the craniofacial skeletal structure by means of cephalometric analysis. Results: All patients suddenly developed a centric relation/centric occlusion discrepancy, an increased overjet and an anterior open bite following ADD WO R. All patients had Angle's Class I occlusion and shallow bite, but they had skeletally Class III and Class II pattern and all were vertically significant hyperdivergent type. Conclusions: These 3 patients had characteristics of common facial morphology including:(1)Angle classification Class I and shallow bite,(2)high mandibular plane angle,(3)high gonial angle. Developed anterior open bite resulted from clockwise rotation of the mandible related TMJ ADD WO R, rather than a result from the eruption of posterior teeth. We hypothesize rotation may relate to attached direction of masticatory muscle.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.115-124
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• 2002

The purpose of this study was to establish regression equations and probability charts for predicting the sum of mesiodistal crown diameters of unerupted unilateral canine and premolars from the sum of mesiodistal crown diameters of four mandibular incisors in Korean male and female. The plaster casts of 162 children(75 boys and 87 girls) among the contestees in 1994-2001 Healthy Dentition Contest in Seoul were measured. Sex differences are compared and the following results were obtained: 1. Bilateral comparison of sum of widths of permanent canine and premolars showed no significant differences for either sex(p>0.05). Sum of widths of permanent canine and premolars of male were significantly larger than that of female(p<0.01). 2. Regression equations for the prediction of sum of widths of permanent canine and premolars in each sex were as follows Male ${\Sigma}Maxillary$ 345 y= 10.45+0.53x Male ${\Sigma}Mandibular$ 345 : y= 10.07+0.51x Female ${\Sigma}Maxillary$ 345 : y=12.65+0.42x Female ${\Sigma}Mandibular$ 345 : y=11.70+0.42x Male+female ${\Sigma}Maxillary$ 345 y=11.01+0.50x Male+female ${\Sigma}Mandibular$ 345 : y=9.87+0.51x

• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.175-183
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• 2000

The purpose of this study was to identify the compensatory adaptation of dentoalveolar structure according to the various skeletal relation through the statistical correlation between the anteroposterior, vertical skeletal and dentoalveolar relation. For this study, the sample were consisted of 101 adult subjects (51male and 50 female, mean age; male 23.6 years, female 21.5 years) who had good occlusion with the range of normal overjet and overbite and acceptable Angle's class I molar relationship which had not been related orthodontically The results were as follows : 1. Even though acceptable normal occlusion, the range of measurements which represent anteroposterior, vertical skeletal relation and dentoalveolar relation were very wide. 2. Upper and lower incisor axis were significantly correlated with anteroposterior skeletal relation, which means the mote lingual inclination of upper anterior teeth and the more labial inclination of lower anterior teeth according to the more anterior position of mandible to the maxilla (P<0.01). 3. Upper and 1ower anterior alveolar bone height was statistically correlated with the lower anterior vertical skeletal height. 4. Upper and 1ower alveolar bone height were not correlated with anteroposterior skeletal relation (P>0.05). 5. The correlation between the incisor axis and vertical skeletal was more closely related in upper anterior teeth than the lower anterior teeth. To summarize the above results, even though acceptable normal occlusion, skeletal and dentoalveolar relation was very widely ranged, and there were close relationship between the anteroposterior skeletal relation and the inclination of upper and lower anterior teeth and between the vertical skeletal relation and upper and lower anterior alveolar bone height. These finding can be concluded as compensatory adaptation to the different skeletal relationship.

• The Journal of the Korean dental association
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• v.22 no.5 s.180
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• pp.383-385
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• 1984

생활양식의 변화에 따라 유치 및 유영구치에 대한 traumatic injury가 크게 증가하고 있으며 이는 어린이나 보호자에게 심리적으로 커다란 영향을 미칠 수 있는 것이다. 어린이의 신체중 구강주위에 가장 많은 injury를 받는 것으로 나타나고 있고 하악전치 보다는 상악전치가, 여자 보다는 남자가 더욱 많은 injury를 받는 것으로 알려져 있으며 유전치에 대한 injury가 가장 많은 시기는 걷는 것, 달리는 것을 처음 재우게 되는 1½~2½세 사이이다. 물론 같은 어린이가 수회의 injury를 받을 수 있으며 특히 조심성이 없거나 가정이 파괴된 상태의 어린이에 있어 사고 위험이 높은 것으로 나타나고 있다. 일단 injury가 발생하면 가능한 한 빨리 치료가 이루어져야 하는데 유치는 계승치 맹출에 의하여 정상적인 치근 흡수현상을 나타내고 발육중인 유영구치는 치근이 미완성된 상태이므로 성숙된 영구치와는 처치방법이 다르며 때 고려해야 할 사항으로, ① management of child, ② degree of root resorption (degree of permanent tooth development), ③ space problems, ④ degree of parental concern, ⑤habits, ⑥ speech, ⑦ esthetics등이 있다.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.359-372
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• 1997

This study was conducted to discern differences of craniofacial, dentoalveolar structure and model measurements between sex and between class n openbite group and non-openbite group. The sample consisted of 49 adult patients with class Il malocclusion. 24 linear measurements, 22 angular measurements and 12 ratios were selected in lateral cephalometry. Also, arch width, length, anterior crowding, average molar relation were measured or calculated in diagnostic model. The data were evaluated by t-test and multiple discriminant analysis. The results were as follows, 1. Most linear measurements, with the exception of MnBL and AUDH, were significantly larger in male(p<0.05). but, intermaxillary relations and spatial position of maxilla and mandible relative to cranial base were not different for both sex. 2. With the exception of upper and lower anterior crowding, lower arch width, upper arch length, AMR, male exhibited significantly larger measurements in model analysis (p<0.05). 3. Size differences of maxilla and mandible between openbite and non-openbite group were not significant(p>0.05). but openbite group showed significantly increased genial angle(p<0.05), FH-CoGo(p<0.01), FH-NA(p<0.01) and FH-NB, FH-NPog (p<0.05). 4. ALFH and PUDH were larger(p<0.05) in openbite group. this result served as compensation for the spatial position of mandible relative to cranial base. AUPUDH (p<0.001) and ALPLDH(p<0.05) were lower in openbite group. upper anterior crowding was the only measurement which showed difference between openbite and non-openbite group(p<0.05). 5. For the purpose of classifying adult class n openbite and non-openbite group, multiple discriminant analysis was done genial angle, ALPLDH, AUPUDH, FH-NA were included in multiple discriminant equation. 39 cases($92.86\%$) were correctly classified when applied to the sample used in this study.

• Journal of the Korean Society of Radiology
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• v.7 no.4
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• pp.301-305
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• 2013

This thesis intends to analyze tooth distortion by mandibular arch form by reproducing existing panorama image and reconstructed panorama image of Cone Beam CT data with the three-dimensional computer program. The diameter of tooth measured in Cone Beam CT's cross-section image and reconstructed panorama was synchronized without any big change from incisors to posteriors. But, panorama showed serious distortion as going to posteriors after showing a little distortion in incisors. The panorama reconstructed for patients' individual arch showed reduced distortion than panoramas used generally. In addition, panorama showed serious distortion from incisors to posteriors and it means that distortion is reduced in reconstructed panorama.