• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.97-102
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• 2012

Odontoma is a mixed tumor formed by the overgrowth of ectodermal epithelial cells and mesodermal cells. It arises during normal tooth development and only grows to a certain level. It is not a true neoplasm and therefore it is considered as hamartomas. Odontomas are classified into compound and complex types based on morphology. Compound odontoma is commonly found in the anterior region of the maxilla, and has a radiopaque lesion that resembles small teeth. Usually, odontoma is treated by conservative surgical removal and there is little probability of recurrence. This paper describes three cases of compound odontoma diagnosed in children with 1 year of follow-up. These case reports present patients having eruption disturbance of primary and permanent teeth due to the presence of compound odontoma. In order to induce spontaneous eruption, conservative surgical removal was performed showing favorable results.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.548-555
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• 2008

Dentigerous cyst is the most common type of odontogenic cyst followed by radicular cyst. Most of dentigerous cysts originate from the permanent dentition and a few of them are associated with mesiodens. The complications of a dentigerous cyst associated with mesiodens are eruption abnomalies of adjacent teeth, root resorption, displacement, rotation, diastema and the secondary infection of the cyst due to adjacent teeth. The treatment of a dentigerous cyst of a maxillary mesiodens is to enucleate a cyst with a mesiodens. Otherwise, when it is close to adjacent teeth, a cyst is to reduce the through marsupialization after removing a mesiodens. There are numerous studies on dentigerous cysts and mesiodentes alone; however, the studies on the association of the two are rare. These are case reports about patients with mixed dentition whose dentigerous cyst of a maxillary mesiodens had been removed. After removal, the patients have been regularly checked up and shown satisfactory progress.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.500-507
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• 2011

Acoustic emission(AE) signals during the polymerization shrinkage of composite resin subjected to the LED light exposure were detected through a wave guide method and a direct sensor attachment method. For PMMA, human tooth, stainless steel substrate, data of AE hits and amplitudes were compared. For the test using the wave guide, AE amplitudes decreased because of the attenuant wave. However, AE hits and 1st peak frequency distribution were not different according to the sensor attachments. Through the experiments, wave guide could be used for a nondestructive evaluation of the marginal disintegrative fracture of dental restoration.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.157-163
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• 1999

The purpose of this study was to investigate the effect of electromagnetic field in orthodontic tooth movement, and the optimal application period of electromagnetic field to initiate tooth movement. Eighty male Hartley guinea pigs were utilized in this study. Laterally directed orthodontic force was applied to the maxillary central incisors. Half sine-wave pulsed electromagnetic field(HSPEMP) was applied to experimental group during 10 days. According to the period of application of HSPEMP(4 hours, 8 hours, 12 hours a day), they were divided into the three sub-groups The obtained results were as follows; 1. In case of application of HSPEMF during 4 hours a day, there was no significant difference in the final amount of orthodontic tooth movement between the experimental and the control group. 2. In case of application of HSPEMF during 8 and 12 hours a day, there was a significant increase in the final amount of orthodontic tooth movement since the eighth day, the sixth day respectively. 3. In comparison with the case of application of HSPEMF during 8 hours a day, there was a significant increase in the final amount of orthodontic tooth movement at the seventh day and the eighth day in case of application of HSPEMF during 12 hours a day.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.303-308
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• 2011

Tooth impaction refers to situations in which the eruption is inhibited by some physical barriers in eruptive path and the tooth remains unerupted beyond the normal time of eruption. The etiology of impacted tooth is controversial, but ankylosis has been suggested probably as a leading role. Impacted primary molars may cause several problems such as space loss, tipping of adjacent teeth, supra-eruption of the antagonists, dislocation of succeeding premolar, cystic change and infection. As one of conventional treatments of impacted primary molars, early tooth extraction or surgical extraction following space regaining when there is space loss has been suggested. However, when they are in normal formation and not ankylosed, orthodontic traction following surgical exposure can be the choice of treatment. In this case, a 3-year-old boy was referred to the department of pediatric dentistry for the unerupted mandibular right second primary molar. After surgical removal of gingiva on the occlusal surface, orthodontic traction was performed. After treatment, we could get normal alignment of primary teeth and the opportunity for normal development of permanent teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.1
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• pp.62-68
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• 2015

Supernumerary teeth (SNTs) refer to extra teeth over normal numbers. SNTs can influence adjacent teeth and structure. Therefore, it is important to find SNTs before they cause problems and to decide when to extract them. Etiology of SNTs has not exactly been found, but it has been proposed that genetic and environmental factors are associated. SNT appears as a single unit in most cases and multiple SNTs usually occur as a part of a syndrome. Non-syndromic multiple SNTs are rarely seen. This report is to document the occurrence of multiple supernumerary premolars in a father and his three sons. Heritage is an important factor in SNT development so familial history is important for early detection of SNT.

• The Journal of the Korean dental association
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• v.24 no.9 s.208
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• pp.761-766
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• 1986

Crowding은 치열의 어느 곳에서나 발생하나 측철치와 견치 사이에서 가장 많이 발생하고 특히 하악 전치 부위에서 다발하여 이 부위의 정상 배열은 그렇게 많이 관찰되지 않는다. 서양 백인과 동양인의 경우에서는 연령의 증가에 따라 발생 빈도가 증가한다. 그러나, 흑인에 있어서는 치아의 크기가 큰데도 불구하고 연락의 증가에 다라 발생 빈도가 증가하지 않는다. 남녀의 발생빈도에 대한 연구 보고에 의하면 여자에서 많이 발생한다고 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.29-37
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• 2019

The purpose of this study was to investigate the characteristics of intrusion in primary dentition and to evaluate factors influencing complications of primary and permanent dentition during long-term follow-up period. 61 patients (84 teeth) were selected in this study. Medical records of 61 patients were reviewed and age, gender, cause of injury, site of injury, severity of traumatic injury, other injuries associated with trauma, treatment method, and complications of primary and permanent dentition were examined. Collected data were statistically evaluated using Chi-square test and Fisher's exact test. Intrusion in primary anterior teeth was predominant in boys over girls and fall was the most common cause of trauma. It was most common at home and occurred most in the primary maxillary central incisors. Severity had an effect on the incidence of sequelae in permanent successors (p = 0.014). The incidence of complications was significantly lower in patients with soft tissue injuries than in patients with other periodontal injuries (p = 0.000).

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.73-78
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• 2012

Complex odontomas consist of a conglomerate mass of enamel, dentin and cementum which bears no anatomic resemblance to a tooth. The majority of these lesions are completely asymptomatic, being discovered on routine radiographic examination or when films are taken to determine the reason for tooth eruption failure. Compound odontomas seldom cause bony expansion, but complex odontomas often cause slight or even marked bony expansion. Complex odontomas are mostly associated with permanent teeth and very rarely associated with deciduous teeth. They are usually located in the first-or second-molar areas of the mandible. This report presents a case of a patient with impaction of a maxillary primary canine by a complex odontoma in which surgical excision of the lesion was performed. And the primary canine was repositioned right under gingival level for spontaneous erution. Follow-up after six months showed spontaneous eruption ofthe repositioned maxillary primarycanine.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.254-263
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• 2016

Many studies on the prognosis of avulsed teeth were published but follow-up studies on Korean children and adolescents are insufficient. The aim of this study was to identify clinical factors determining the healing and prognosis of permanent incisors that were replanted after avulsion injury. This study included 184 permanent teeth in 142 patients aged 6-14 years. The clinical and radiographic data of the patients were analyzed from electronic medical records. Immature teeth had a higher probability of pulp revascularization than mature teeth. When extra-alveolar time was longer than 60 minutes, the incidence of inflammatory root resorption (IRR) was higher in immature teeth than mature teeth. However, the incidence of replacement root resorption (RR) was higher in mature teeth than immature teeth under the same condition. The incidence of IRR was increased when pulp was extirpated more than 20 days after replantation. IRR had a more significant influence on the decrease of survival expectation than RR. There was no significant correlation between the root development stage and survival expectation. However, when RR occurred, immature teeth survived shorter than mature teeth. Long term follow-up results from this study are expected to be used as fundamental data for the treatment guidelines and evaluation of the prognosis of replanted teeth.