• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.248-261
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• 1999

In order to define a current set of Korean children norm with mixed dentition, following study was done. The subjects were 102 healthy dentition contestants(48boys, 54girls). Standardized lateral head roentgenograms were taken, and Ricketts analysis was done. Results were as follows: 1. Length of anterior cranial base, posterior facial height, corpus length were longer in male than in female(p<0.05), and Porion was located posteriorly in male than in female(p<0.01). 2. Through facial depth, Pogonion of male was more forwardly positioned(p<0.05), mandible was significantly steeper in female, and maxillary anterior teeth were significantly tipped forward in male(p<0.05). 3. Variables such as length of anterior cranial base, upper molar position(p<0.01) and corpus length(p<0.05) were significantly changed by age. 4. Maxillary height, facial depth, mandibular plane angle, convexity were changed by age, but not significantly(p>0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.108-115
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• 2017

Numerous therapeutic approaches are available for impacted teeth, including orthodontic retraction, implantation, and autogenous tooth transplantation. Autotransplantation is a promising method, especially for juvenile patients, as it enables preservation of the function of the periodontal tissues, as well as continued alveolar bone growth. This report describes autotransplantation in two cases in which the tooth was fully-ectopically impacted. With case 1, an ectopically impacted premolar was extracted and transplanted in an upright position, and regenerative endodontic treatment was performed using a platelet-rich fibrin clot and mineral trioxide aggregate (MTA). With case 2, a calcifying odontogenic cyst with an impacted left mandibular second molar was treated by enucleation. The tooth was transplanted into the proper position 3 months after enucleation, and endodontic treatment was performed using MTA. In both cases, autotransplantation appeared to provide a simple and rapid treatment option for patients with ectopically impacted teeth. These cases demonstrate that autotransplantation of ectopically impacted teeth is a viable treatment option rather than implant placement or prosthesis, especially in juvenile patients.

• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.289-301
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• 2004

It is the purpose of this study to characterize oral symptoms and to comprehend the cause and the relapse possibility of patients with open bite. This case study examines the orthodontic treatment of a group of female patients with open bite and Angle's Class I malocclusion. A cephalograph of the patient was taken and tracing of the radiograph was completed. In addition to Bjork and Ricketts analysis, additional measurements of specific areas were taken. The occlusal plane was determined by drawing a line connecting the mesiobuccal cusp tip of the maxillary first molar and the incisal edge of the maxillary central incisors. Patients were divided into two groups depending on the relationship between the marginal ridge of the maxillayy first premolar and the drawn line. Those patients with marginal ridges above the occlusal plane were placed into Group 1, while Group 2 subjects exhibited marginal ridges lower than the occlusal plane. The common characteristics within each group and the characteristic differences between each group both prior to and after orthodontic treatment were examined, and finally, the functional oral volume of each patient was analyzed. The results of the case study were as follows: 1. An examination of the skeletal relationship and anatomical form for both Group 1 and 2 showed that all subjects exhibited hyperdivergent skeletal forms, but Group 2 subjects generally demonstrated underdevelopment of the mandible and a smaller articular angle, resulting in an anterior positioning tendency of the mandible. 2. An analysis of the maxillary arches of Group 1 subjects prior to and after orthodontic treatment showed that the antero-inferior direction had changed to an antero-superior directional tendency, while the maxillary arches of the Group 2 patients showed a trend from an antero-superior direction to an antero-inferior relationship. The mandibular arches in both groups showed a change to an antero-superior direction. 3. Functional space analysis showed that Group 2 patients exhibited a greater tendency of haying palatal planes that drop in a postero-inferior direction, resulting in a more severe open bite than their Group 1 counterparts. The results of this case study show that although patients belonging to either Group 1 or 2 exhibited few external differences in the appearance of open bite, an examination of the dental and skeletal relationships by analyzing patient cephalographs showed that patients presenting with flat maxillary occlusal planes exhibited more severe open bite relationships than patients with curved occlusal planes.

• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.129-142
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• 1995

The purpose of this study was to estimate correlations of craniocervical posture and craniofacial morphology in Korean young adults. The sample consisted of 50 young adults (25 males and 25 females) who had good profile and Class I molar relationship. The analysis of craniocervical posture and craniofacial morphology was performed on lateral cephalograms taken in natural head position. The results were as follows, 1. The mean and the standard deviation of postural and morphologic variables were obtained. 2. Korean young adult had cervical lordosis of which degree between OPT and CVT shows $3.55{\pm}2.58^{\circ}$ 3. Craniocervical posture and each of vertical ratio, facial prognathism, mandibular rotation showed high correlation. 4. Correlation coefficients between postural variables and each of intermaxillary relation, anteroposterior ratio were low. 5. The head positioning error of natural head position was smaller than the inter-individual variability of postural variables.

• Imaging Science in Dentistry
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• v.40 no.1
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• pp.39-44
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• 2010

Purpose : We want to identify the appearance of the buccolingual root dilaceration teeth in the panoramic views and specify the characteristics of these teeth. Materials and Methods : One thousand-six patients were examined on the basis of both panoramic and CT image criteria. We diagnosed and excluded certain teeth from the samples; both prosthodontic or pathologic lesion appearing teeth and mesiodistally dilacerated ones. We meticulously discerned buccolingually dilacerated teeth in the CT images and total 48 samples were selected. The degree of severity in dilaceration was standardized by 2 types of criteria. The samples were differentiated into 3 groups and again categorized into six types showing from the panoramic views: irregular view on the root apex area, clear blunt on the root tip, stepping on root tip, double lamina dura or double tip, arrow-target shaped root, bull's eye, normal view. Results : The types of teeth selected from total 48 buccolingual root dilaceration samples were mandibular first and second molar, premolars, canines, and lateral incisors. The direction of dilaceration was an even percentage to each buccal and lingual side for most selected teeth, however, that of both canines and lateral incisors were directed in almost a buccal side. In the panoramic views, the root types of the buccolingually dilacerated teeth were irregular view on the root apex area, clear blunt on the root tip, stepping on root tip and normal types were almost always normal view. The more severity in dilareated degree, the more chances of observation in the panoramic views were clear blunt on the root tip and stepping on root tip. Conclusion : As observed in the shape of stepping on root tip or double lamina dura in the panoramic views, there can be much more probability to diagnose as a buccolingually dilacerated root.

• The Journal of Advanced Prosthodontics
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• v.9 no.5
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• pp.341-349
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• 2017

PURPOSE. This study evaluated the accuracies of different bite registration techniques for implant-fixed prostheses using three dimensional file analysis. MATERIALS AND METHODS. Implant fixtures were placed on the mandibular right second premolar, and the first and second molar in a polyurethane model. Aluwax (A), Pattern Resin (P), and Blu-Mousse (B) were used as the bite registration materials on the healing abutments (H) or temporary abutments (T). The groups were classified into HA, HP, HB, TA, TP, and TB according to each combination. The group using the bite impression coping was the BC group; impression taking and bite registration were performed simultaneously. After impression and bite taking, the scan bodies were connected to the lab analogs of the casts. These casts were scanned using a model scanner. The distances between two reference points in three-dimensional files were measured in each group. One-way ANOVA and Duncan's test were used at the 5% significance level. RESULTS. The smallest distance discrepancy was observed in the TB group using the temporary abutments. The Blu-Mousse and HP groups showed the largest distance discrepancy. The TB and BC groups showed a lower distance discrepancy than the HP group (P=.001), and there was no significant difference between the groups using the temporary abutments and healing abutments (P>.05). CONCLUSION. Although this study has limitations as an in-vitro investigation, the groups using the temporary abutments to hold the Blu-Mousse record and bite impression coping showed greater accuracy than the group using the healing abutments to hold the pattern resin record.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.282-289
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• 2020

Purpose: The aim of this in vitro study was to evaluate the accuracy of three different intraoral scanners (IOSs) on digital impressions of different types of endocrown cavity preparations. Materials and methods: Two human mandibular molar teeth were prepared with different endocrown abutment designs: one with a buccal wall (Class 2) and the other without a buccal wall (Class 3). Both cavity designs were scanned using a reference desktop scanner (E3) and three different intraoral scanners: Trios3 (TRI group), Cerec Omnicam (CER group), and i500 (I5 group). The obtained Standard Tessellation Language (.stl) datasets were exported to metrology software. The precision was evaluated based on deviations among repeated scan models recorded by each IOS. The trueness was evaluated based on deviations between the reference data and repeated scans. For detecting interaction, data were statistically analyzed using a univariate analysis of variance (ANOVA) and for analyzing the comparison of the test groups data were analyzed by one-way ANOVA and post-hoc Tukey test at the significance level of .05. Results: The deviation values for both cavity designs in the I5 group were significantly lower than those in the other IOS groups in terms of trueness. For both cavity designs, the TRI group exhibited better precision than the other IOS groups. Conclusion: Different technologies of IOS device's and different endocrown prepration designs affected the accuracy of the digital scans.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.18-25
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• 2005

Traumatic bone cyst is a nonodontogenic cyst without epithelial-linig which contains fluid in it's cavity, and it is limited by bone walls with no evidence of infection. Traumatic bone cyst is asymptomatic and appears more frequently in the second decade. Gender distribution is approximately equal, although males are affected slightly often than females. Radiographically the lesion shows a well demarcated radiolucent lesion of variable size and the lesion may have scalloped margins. The adjacent teeth to traumatic bone cyst remains vital. Traumatic bone cyst is usually treated by surgical exploration and currettage of the lesion. In the first case of this case report, the patient was refered from the local dental clinic for the radiolucent area under the left mandibular first molar. From the panorama radiograph at the first visit, the radiolucent area of the left mandible showed a well defined scalloped margin and identified as traumatic bone cyst. In the second case, the patient have visited for the chief complaint of swelling and abcess of right maxillary second premolar. In the radiographic check up with panorama radiograph, the radiolucent lesion with well demarcated scalloped margin was found in the right mandible body, and identified as traumatic bone cyst. In the first case, overinstrumentation was done through the mesial root canal to irrigate the lesion. In the second case, not any treatment was done, and watched the progression of the lesion. And in both cases, after two month, the radiolucency and the size of the lesion has decreased to show healing in progress.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.658-665
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• 2007

Oligodontia is defined as the congenital absence of six or more teeth in dentition, excluding the third molars. The prevalence of congenital missing teeth is about 1.6 to 9.6% of population and the prevalence of oligidontia is about 0.08 to 1.1%. The mandibular second premolar is the most frequently absent after the third molar, followed by the maxillary lateral incisor and upper second premolar. Females seem to be affected slightly more than males. Oligodontia may occur either in isolation, or as a part of a syndrome such as ectodermal dysplasia. Different causes are possible for oligodontia: physical obstruction or distruction of the dental lamina, space limitation, functional abnormalities of the dental epithelium, failure of induction of the underlying mesenchyme, chemotherapy, radiotherapy or genetic factor. Because oligodontia would result in esthetic and functional problems, such as facial asymmetry or occlusal disharmony, early diagnosis from clinical and radiographic examination was necessary. And appropriate treatment plan should be followed. This case report was about oral conditions and treatment of the oligodontia patients who have no specific systemic disease.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.255-268
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• 1998

This study was investigated to assess the difference of facial height and occlusal plane inclination between normal occlusion group and class II malocclusion group. The subjects consisted of 50 normal occlusion (male 25, female 25) and 50 class II(male 25, female 25) malocclusion patients. All subjects are adult. lateral cephalogram was taken with standard method traced, and digitized for each subjects. The computerized statiscal analysis was carried out with SPSS program. The results were as follows 1. In class II malocclusion group, variables significant different from normal occlusion group were as follows ; SN-FOP, FH-BOP, MP-BOP, AB-BOP, AB-FOP, Facial plane-BOP, FP-FOP 2. In class II malocclusion group, the posterior facial height -especially posterior lower facial height-was significantly smaller than normal occlusion group.(P<0.05) 3. In class II malocclusion group, the angles between occlusal plane and upper and lower incisor, the angle between upper molar and bisected occlusal plane were significantly larger than those of normal occlusion group. (P<0.05) 4. L1 to Mandibular plane (mm) was a unique factor of occlusal plane position that showed significant difference in class II malocclusion group. 5. The correlation between overbite and occlusal plane inclination existed in class II malocclusion group, but the correlation didn't exist in normal occlusion group.