• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.357-366
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• 2008

Posterior cross-bite is a relatively frequent malocclusion in primary and early mixed dentition and the reported prevalence of posterior cross-bite varies from 7% to 23%. It has been defined as a transverse discrepancy in arch relationship which the palatal cusp of the upper posterior teeth do not occlude in the central fossa of the opposing lower teeth, and can be manifested in a single tooth or in a group of teeth. Posterior cross-bite does not often self-correct and therefore immediate treatment is recommended. Occlusal adjustment to eliminate premature contact that causes mandibular deviation, expansion of narrow maxillary arch, arrangement of the individual teeth to treat asymmetry within the dental arch are the methods of treating cross-bite. In the present case, functional posterior cross-bite was observed in the primary and the early mixed dentition children. The children were treated by the slow maxillary expansion and occlusal adjustment. The outcome of periodic examinations after the correction of cross-bite was favorable.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.122-128
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• 2021

Short root anomaly (SRA) is a rare dental condition with abnormally short and blunt root morphology. It mostly affects maxillary central incisors symmetrically and only has been observed in permanent teeth. A 9-year-old girl was referred from a local dental clinic for short root development in mixed dentition with no symptoms. Radiographic and intraoral examinations revealed SRA on upper and lower incisors and mandibular first molars along with other dental anomalies such as enamel hypoplasia and dens invaginatus. During long - term follow - up for 5 years, her mixed dentition has changed to permanent dentition and generalized SRA was observed in all permanent teeth. Cephalometric radiograph also revealed the calcification between the anterior and posterior clinoid processes described as a sella turcica bridge which was reported associating with dental anomalies. Early diagnosis of SRA is emphasized for successful management and prevention of root resorption and tooth loss. This report aimed to present a rare case of generalized SRA along with other dental anomalies and sella turcica bridging in a female patient through long - term follow - up.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.147-157
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• 2019

This study aimed to evaluate skeletodental characteristics of patient with maxillary lateral incisor agenesis (MLIA) in mixed dentition. It involved the children in early mixed dentition who visited Pusan National University dental hospital for orthodontic purposed and had intact primary canines. 38 children with MLIA and 38 controls with the same chronological age satisfying the inclusion criteria were selected. The craniofacial structures and dental arch dimensions of the MLIA were evaluated using model & cephalometric analysis and compared to controls. The rate of unilateral MLIA was high in male and the rate of bilateral MLIA was high in female. In model analysis, the width / length ratio of maxillary anterior portion of the MLIA group were higher and arch perimeter of the maxilla of the MLIA group were smaller than those of the control group (p = 0.003, 0.04). Cephalometric analysis showed that there were no significant differences in terms of skeletal, dental analysis. In soft tissue profile, nasolabial angle was larger in MLIAs than in controls (p = 0.039). Considering these skeletodental characteristics of MLIA, early diagnosis and proper management is highly recommended to minimize the possibility of functional defect.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.73-84
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• 2007

The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.555-567
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• 1994

The purpose of this study is to observe the effect of high pull headgear on the craniofacial structures of mixed dentition with Class II malocclusion. The cephalometric headplates of 16 children treated by high pull headgeaar during 6 months and 18 children during 12 months were traced, digitized and statistically analyzed. The results were as follows. 1. Inhibition of foreward growth of maxilla was observed in both group. 2. Clockwise rotation of maxilla was observed in both group. 3. There were distal movement of maxillary 1st molar and inhibition of alveolar bone growth of maxilla. 4. There was compensatory extrusion on mandibular 1st molar. 5. The ratio of anterior facial height to posterior facial height was almostly not changed. In the treatment plan of C II malocclusion by high pull headgear, ire must prevent the mandibulasr 1st molar from extruding and for orthopedic effect, at least 6 months is needed.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.107-113
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• 1983

20 children who visited department of pedodontics, S.N.U. Hospital were examined and their study models were obtained. The data obtained from three groups of operator, three method, twice measurement, was analysed. The results of the study were as follow: 1. The Brass-wire method appears to be the least desirable of those examined for space predictions in all three groups of operators. 2. It appears that there is little clinical significance between Moyer's and Segmented-arch method in all three groups of operators. 3. The Moyers' method appears to be more easily conceptualized by inexperienced operators than the other two methods.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.11-19
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• 1975

This study was undertaken to investigate the exact values of the cephalometric standards of Hellman dental age III B groups of Korean in the reontgenocephalometry. The subjects consisted of 25 males and the same number of females with the normal occlusion and acceptable profile. Each lateral cephalometric head film was taken with the teeth in occlusion and the Focal-film distance was 300cm. Their linear and angular measurements were made directly. The following conclusions were obtained; 1) The author made the tables of standard deviation from the measured values. 2) The degree of the facial convexity of Korean children was larger than that of the white. 3) The labial inclination of the lower central incisor in male was a little greater than that in female.

• The korean journal of orthodontics
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• v.39 no.2
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• pp.112-119
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• 2009

Objective: To develop a mixed dentition analysis method in consideration of the normal variation of tooth sizes. Methods: According to the tooth-size of the maxillary central incisor, maxillary 1st molar, mandibular central incisor, mandibular lateral incisor, and mandibular 1st molar, 307 normal occlusion subjects were clustered into the smaller and larger tooth-size groups. Multiple regression analyses were then performed to predict the sizes of the canine and premolars for the 2 groups and both genders separately. For a cross validation dataset, 504 malocclusion patients were assigned into the 2 groups. Then multiple regression equations were applied. Results: Our results show that the maximum errors of the predicted space for the canine, 1st and 2nd premolars were 0.71 and 0.82 mm residual standard deviation for the normal occlusion and malocclusion groups, respectively. For malocclusion patients, the prediction errors did not imply a statistically significant difference depending on the types of malocclusion nor the types of tooth-size groups. The frequency of prediction error more than 1 mm and 2 mm were 17.3% and 1.8%, respectively. The overall prediction accuracy was dramatically improved in this study compared to that of previous studies. Conclusions: The computer aided calculation method used in this study appeared to be more efficient.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.430-437
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• 2007

The probability table of Moyers and prediction equation of Tanaka and Johnston that have been the most frequently used, cannot produce accurate prediction when used in Korean because they are based on the Caucasian popularity of the Northern European race. The method of Moyers or Tanaka and Johnston predicts sizes of the unerupted canine and premolars on the basis of the sizes of mandibular incisors. However, some of the recent papers raise a question as to whether the mandibular incisors are the best combination to predict the sizes of the unerupted canine and premolars. The purpose of this study is to determine which sum or combination of sums of permanent tooth widths present the best prediction for the unerupted canine and premolars in a Korean sample, to calculate a specific linear regression equation for this population, and to evaluate the clinical significance. A new linear regression equation was calculated based on the data of 178 Korean young adults(70 women, 108 men, mean age 21.63 years) with complete permanent dentitions. Fifty three more children(28 girls, 25 boys, mean age 14.22 years) were used as a validation sample for the application of the multiple linear regression equation. The conclusions were as follows: 1. The combination of the sums of permanent upper central incisors, lower lateral incisors and upper first molars was the best predictor for the unerupted canine and premolars in this sample($r=0.65{\sim}0.80$). 2. The multiple linear regression equation was calculated including sex and arch as additional predictor variables. male, upper: $Y\;=\;0.332{\times}X_0\;+\;6.195$ male, lower: $Y\;=\;0.332{\times}X_0\;+\;5.269$ female, upper: $Y\;=\;0.332{\times}X_0\;+\;5.929$ female, lower: $Y\;=\;0.332{\times}X_0\;+\;5.003$. The determination coefficient of the equation was 64% and a standard error of the estimate was 0.71mm. 3. In about 97% of the validation sample, the estimation of the tooth width sums of unerupted canine and premolars using the new multiple linear regression equation was smaller than 1mm compaired with the actual values.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.119-128
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• 2011

In the process of assessing the children with anterior crossbite in early mixed dentition, it has frequently been detected that the stronger the skeletal pattern of the malocclusion is, the more markedly delayed the development and eruption of maxillary teeth are. If the anteroposterior characteristics of craniofacial skeleton has any relationship with dental maturation, the evaluation of dental development and eruption was thought to be able to contribute to early diagnosis of crossbite in children. This study was performed for the purpose of elucidating the relationship between dental maturation of maxillary teeth and some cephalometric values in children with anterior crossbite of maxillary undergrowth type in early mixed dentition. Among the children in Hellman dental age IIA and IIC who attended the Pediatric Dental Clinic of Pusan National University Hospital with orthodontic problems, cases with Class III malocclusion were classified and 50 cases of maxillary undergrowth type and type with normal maxilla respectively were randomly selected and studied as subjects. From their lateral cephalographs and panoramic radiographs, their anteroposterior skeletal features, the dental maturity and eruption rate were obtained of each group and data were analyzed to yield the results as follows: 1. Comparing the maturity of maxillary teeth of both groups, only the first molars of maxillary undergrowth group showed significantly slower development and eruption (p<0.05). 2. There was high correlation between maturation of maxillary 1st molar and chronological age(p<0.05). 3. Among the parameters of anteroposterior relationship of skeletal pattern in maxilla and mandible. Wits was revealed as a useful index to predict both the calcification and eruption rate of the 1st molars whereas SNA was to eruption rate(p<0.05).