• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.363-372
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• 2003

Supernumerary teeth are found frequently in the dental office causing many dental complications. They are one of the many dental abnormalities that may occur during tooth development. Inversely impacted supernumerary teeth in the midpalatal area are especially important clinically because they occur with high frequency and many complications. Though many previous clinical and radiographical studies exist, the sample numbers were small and the evaluation of shape, location, and effects to its surrounding tissue may not be accurate due to the solitary use of intraoral radiographs or panoramic radiographs. Among the patients who visited department of pediatric dentistry, yonsei dental hospital, from July, 1998 to June, 2002, those with inversely impacted supernumerary teeth took computerized tomography for a more accurate diagnosis. Their dental chart, panoramic radiograph and computerized tomography were evaluated for this study. The number, form, convexity, location, distance, and complications of inversely impacted supernumerary teeth in the midpalatal area were recorded. This study show that when the supernumerary teeth is tuberculated with a curved root and is in close proximity to the adjacent teeth, it causes complications such as eruption disturbance, rotation, displacement of adjacent teeth, and diastema. Such factors must be considered in making decisions for diagnosis and treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.56-63
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• 2017

Delayed eruption of the first molar, without a generalized or localized cause, is usually associated with delayed development of the affected tooth. The aim of this study was to investigate the clinical features of the first permanent molar showing delayed development and eruption, and its association with developmental anomalies of other teeth. Panoramic radiographs of 40 healthy children showing delayed development and eruption of first permanent molars were analyzed. The clinical features of affected first molars and developmental anomalies of other teeth (except third molars) were evaluated. Delayed first molars were more frequent in the maxilla. The incidence of bilateral delayed development of first molars was greater than that of unilateral cases in female patients. In contrast, male patients showed unilateral delayed development of the first molar more frequently. A higher incidence of congenitally missing teeth was observed in patients with delayed first molar. In each case, delayed development or congenital absence was observed in the second molar adjacent to the delayed first molar. Overall, delayed first molar seems to be associated with congenital absence of additional teeth. Understanding the developmental mechanisms of this phenomenon requires further studies.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.246-253
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• 2016

The optimal time for the removal of supernumerary teeth can be divided into two groups; early removal and late removal. While each group has its own advantages, the effects on maxillary central incisor can be significant. The purpose of this study was to determine the ideal time for the removal of the supernumerary teeth by evaluating 166 patients for three months after surgical removal of supernumerary teeth. Relatively young patients in early Hellman's dental stage with less developed or unerupted maxillary central incisor had less midline deviation. No statistical significance was found in diastema, rotation of the maxillary incisors and their changes during a follow-up period. Removal of supernumerary teeth should be considered as a preventative measure prior to eruption of the maxillary incisors when the midline deviation is observed in panoramic radiographic examination. This study will be useful in determining the optimal time for the removal of supernumerary teeth depending on the location of the maxillary incisors. This study will be informative on deciding the optimal time to remove the supernumerary teeth depending on the various positions of the maxillary central incisor. (this sentence is better to use)

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.1
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• pp.25-35
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• 2020

The purpose of this study is to evaluate the morphological characteristics of the roots and roots canals of primary molar teeth using Cone-Beam Computed Tomography (CBCT). A total of 68 CBCT images of children aged 4 - 5 years was used for this study. A total of 160 molar teeth were analyzed. Various parameters such as the number of roots and canals, length of root and root canal, and the angulation and shape of the roots were analyzed. All maxillary primary molars had 3 roots. The presence of 2 root canals in 1 root was only observed in the mesiobuccal root of maxillary primary second molars. Most mandibular primary molars had 2 roots, and most mesial roots had 2 root canals. Concerning the length of the roots, the palatal root of the maxillary primary molar was found to be longest whereas the distobuccal root was shortest. In mandibular primary molars, the mesial root was longer than the distal root. In maxillary primary molars, the palatal root had the greatest angulation whereas the distal root has the greatest in mandibular molars. The root and root canals of maxillary primary molars were more curved in shape whereas mandibular primary molars were straight.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.260-267
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• 2013

The aim of this study was to analyze the three dimensional characteristics of the size, shape and location of mesiodens and their effect on permanent teeth arrangement using Cone-beam computed tomography(CBCT). 191 patients under 15 years old who had visited the hospital between June 2006 and December 2012 and taken CBCT were investigated. Among them, 43 patients with diastema were analyzed to investigate the correlation between the amount of diastema and the mesiodens. The results showed that mesiodens were found in males 3.9 times more than females and found most in 7 years old. The mean length of mesiodens was 13 mm and the width was 6.8 mm. The conical shape comprised of 52.9%. Many mesiodens were located in the palatal side rather than the labial side and located vertically near the crown. 63.0% of mesiodens were reversed and the common complications were delayed eruption followed by diastema, and teeth rotation. And the amount of diastema had correlation with size and mesiodistal position of the mesiodens. The current study used 3D analysis to show the size and position of mesiodens and occurrence distribution of complication. Among these, the amount of diastema had shown the correlation with the size and mesiodistal position of mesiodens.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.91-98
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• 2006

Supernumerary teeth are teeth which result from the continued budding of the enamel organ of the preceding tooth or from excessive proliferation of cells. They are most often found in the maxillary anterior region. And they can be responsible for a variey of irregularities in the primary and transitional dentition. There are two morphological types of supernumerary teeth, supplemental and rudimentary. Supplemental teeth have normal shape and size. In contrast, rudimental teeth have abnormal shape and smaller size. Supplemental supernumerary teeth are most common in permanent lateral incisor area. Its extraction must be decided more carefully with differential diagnosis between normal teeth, because it has normal shape and size. We reports 3 cases of the normal incisor shaped teeth in the maxillary anterior region. In all cases, we used the 3D Dental-CT as well as the conventional plain film such as periapical, occlusal, and panoramic radiograph. Consequently, 3B Dental-CT was valualble to figure out the exact position and morphology of supernumerary teeth, to do more conservative surgery and to reduce surgery stress and time.

• Sijohaknonchong
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• v.44
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• pp.255-279
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• 2016

Ignominy are ashamed or that mind. It is noted that this article 'shame[恥]' will do for obtaining the social dynamics in some way in the literary aspect. To investigate this aspect, this article took the text produced on the basis of 'shame[恥]' to be analyzed. First, through the Sayuksin[死六臣]'s Sijo[時調], 'Shame[恥]' they have confirmed the room to go to form a sympathy by revealing without hidden. It is worth evaluating in common with these Sijo is that of justice or loyalty. But the parameters of evaluation described what people are rare. In this article, I saw the parameter to 'shame[恥]'. Second, through the Sijo created in the war of the middle age of Chosun Dynasty, I examined the aspect of 'anger' which sparked a shame[恥]. Thus shame[恥] is hard to change the world directly. However, the possibility that it can also be a psychological instrument was found to be sufficient. In conclusion, 'shame[恥]' is clearly greater tendency to dismiss as a private act of the heart. But, I understood that the negative region of 'shame[恥]' can be converted to positive region. At this time, The premise of 'shame[恥]' should always be oriented to justice.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.11
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• pp.435-442
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• 2018

Outlier detection means to detect data samples that deviate significantly from the distribution of normal data. Most outlier detection methods calculate an outlier score that indicates the extent to which a data sample is out of normal state and determine it to be an outlier when its outlier score is above a given threshold. However, since the range of an outlier score is different for each data and the outliers exist at a smaller ratio than the normal data, it is very difficult to determine the threshold value for an outlier score. Further, in an actual situation, it is not easy to acquire data including a sufficient amount of outliers available for learning. In this paper, we propose a clustering-based outlier detection method by constructing a model representing a normal data region using only normal data and performing binary classification of outliers and normal data for new data samples. Then, by dividing the given normal data into chunks, and constructing a clustering model for each chunk, we expand it to the ensemble method combining the decision by the models and apply it to the streaming data with dynamic changes. Experimental results using real data and artificial data show high performance of the proposed method.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.25-34
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• 2022

This study aimed to investigate a quantitative analysis of the anatomical characteristics of the maxillary supernumerary lateral incisor and its relationship with lateral incisors. Forty-four supernumerary lateral incisors from 43 patients were evaluated for analyzing the position, shape, direction, and relationship between the supernumerary lateral incisor and the normal lateral incisors, using cone-beam computed tomography (CBCT). To compare the size of crown, the mesio-distal width was measured and the Nolla stage was used for evaluating the degree of root development to compare tooth maturity. The supernumerary lateral incisors were in the normal direction at a rate of 90.9%, and in a supplemental shape at a rate of 84.1%. The supernumerary lateral incisor was smaller in size compared to the adjacent lateral incisor and opposite lateral incisor (p < .0001). There was no statistically significant difference in the development stage of root. Based on these results, the supernumerary lateral incisor is similar with the lateral incisor, but has a difference in the size of crown. It is necessary to distinguish the supernumerary lateral incisor from the lateral incisor precisely to reduce clinical complications.

• The Korean Journal of Applied Statistics
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• v.19 no.2
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• pp.305-317
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• 2006

Outliers adversely affect model identification, parameter estimation, and forecast in time series data. In particular, when outliers consist of a patch of additive outliers, the current outlier detection procedures suffer from the masking and swamping effects which make them inefficient. In this paper, we propose new outlier detection procedure based on high breakdown estimators, called as the dual robust filtering. Empirical and simulation studies in the autoregressive model with orders p show that the proposed procedure is effective.