• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.409-422
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• 2005

The aim of this study was to identify the bacteria isolated from acute endodontic lesions by cell culture and 16S rDNA sequencing. The necrotic pulpal tissue was collected from 17 infected root canals, which were diagnosed as being either an acute pulpitis or acute periapical abscess. Samples were collected aseptically from the infected pulpal tissue of the infected root canals using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing 500 ul of 1 XPBS. The sample solution was briefly mixed and plated onto a BHI-agar plate containing $5\%$ sheep blood. The agar plates were incubated in a $37^{\circ}C$ anaerobic chamber for 7 days. The bacteria growing on the agar plate were identified by 16S rRNA coding gene (rDNA) cloning and sequencing at the species level. Among the 71 colonies grown on the agar plates, 56 strains survived and were identified. In dental caries involving the root canals, Streptococcus spp. were mainly isolated. Actinomyces, Clostridia, Bacteroides and Fusobacteria were isolated in the periapical lesion without dental caries. Interestingly, two new Actinomyces spp. (ChDC B639 and ChDC B631) were isolated in this study. These results showed that there was diversity among the species in endodontic lesions, This suggests that an endodontic infection is a mixed infection with a polymicrobial etiology. These results may offer the bacterial strains for pathogenesis studies related to an endodontic infection.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.13 no.1
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• pp.145-150
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• 1983

The author studied clinically and radiologically 55 cases which had been diagnosed as odontoma in SNUDH. The obtained results were as follows: 1. In sex distribution, there was no prevalence in both sexes. And the incidence was the highest in the 2nd decade. (16 patients, 29%) 2. There were 42 cases of compound odontoma (76%) and 13 cases of complex odontoma (24%). In most cases, compound odontoma was located at the anterior portion (34 cases, 81%) and complex odontoma at the posterior portions (9 cases, 69%). 3. There was no apparent clinical symptom in compound odontoma (83%), but in complex odontoma, 80% of case show swelling. 4. The adjacent root resorption was not observed in any case. 5. Five cases radiographically diagnosed as cystic odontoma were not confirmed histopathologically.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.594-597
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• 2006

Ameloblastic fibro-odontoma(AFO) is a rare mixed odontogenic tumor. It is composed of connective tissue characteristic of an ameloblastic fibroma and calcified tissue as a complex or compound odontoma. AFO usually presents itself as an asymptomatic swelling of jaw or failure of tooth eruption. The lesion usually occurs in individual less than 30 years old. The differential diagnosis of this tumor includes odontoma, ameloblastoma, and ameloblastic fibroma. This report describes an ameloblastic fibro-odontoma occurring in maxilla of sixteen-year-old female. The lesion was treated by surgical enucleation and curettage without extraction of the involved canine(#23). This patient has shown no sign of recurrence during postoperative 34 months. So we report our case with review of literatures

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.171-174
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• 2001

This case describes a case of desmoplastic fibroma of the mandible. A 9-year-old boy was seen with a history of progressive swelling and expansion of the left mandible for one month period. Desmoplastic fibroma was diagnosed on histopathologic examination This report reviews the diagnostic criteria, differential diagnosis and surgical treatment of choice in brief of this uncommon primary bone tumor of the oral and maxillofacial region.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.481-489
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• 2007

Maxillary canine impaction is a frequently encountered clinical problem, and it may cause the resorption of adjacent tooth or cystic change. Treatment plan for maxillary canine impaction should be decided among extraction, orthodontic traction and autotransplantation according to several factors such as direction and position of unerupted tooth, degree of developing root apex, eruption space, exsitance of supernumerary tooth, odontoma, or cyst. Autotransplantation is a valuable alternative to extraction of impacted teeth, where surgical exposure and subsequent orthodontic realignment are difficult or impossible due to unfavorable impaction position. And its prognosis is dependent on a number of factors such as preservation of periodontal ligament, degree of root development, surgical technique, patient's age, endodontic treatment, time and type of splinting and storage medium, etc. The patients in these cases visited our dental clinic in the late permanent dentition with the chief complaint of unerupted maxillary canines. And it was thought that the spontaneous eruption guidance or orthodontic traction and alignment were difficult because of its unfavorable impacted position. Therefore, autotransplantaion and endodontic treatment were done and have been checked periodically until now.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.613-618
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• 2009

Impacted molars are not usual with the prevalence rate of less than 1%, however problems such as infraocclusion, extrusion of the opposite tooth and lack of space are caused. If molars are impacted, radiographic check-up and observations are needed as they play an important role in skeletal development and mastication. Causes of impaction are underdevelopment of roots, supernumerary teeth, cysts, odontomas, ankylosis and etc. In our first case, we present impacted molar which was surgically exposed and orthodontically traded. As the developmental state of the root was less than half at first visit, we observed until the root was 2/3 in its length and traction was carried out. The second case is orthodontic traded molar with compleate enucleation of the existing cysts. When trading impacted molars, direct bonding of attachments to the tooth and light continuous forces are recommended so as to ankylosis, external absorption and periodontal attachment loss avoid. Fixed appliances tract the teeth on arch and obtain eruption spaces without patient's cooperation. We report surgically exposed and orthodontically traded molars which resulted in good occlusion and patients satisfaction.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.70-76
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• 2000

Congenital biliary atresia with progressive sclerosis of the intra- and extra-hepatic duct system occurs in 1 : 10,000 live births, and has a poor prognosis with an expected survival of less than 5 years. Etiology of biliary atresia is unclear, however, it is believed a genetic or developmental cause. The clinical characteristics include pronounced jaundice, hepatosplenomegaly, pruritus, steatorrhea, xanthomas, growth retardation, portal hypertension, bleedings, ascites and respiratory infections. Oral manifestations have seldom been reported in patients with biliary atresia, but there may be enamel hypoplasia, delayed tooth eruption, and green teeth. Early diagnosis and surgical intervention have decreased morbidity. returned growth and development to normal and improved the prognosis for survival. Authors report the clinical and radiologic characteristics, proper managements about two cases with biliary atresia.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.19.1-19
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• 1983

The dentigerous cyst involving maxilla is rare disease in Otolaryngologic field. A case of 22-year-old male patient involving dentigerous cyst of the maxilla with chronic inflammatory signs has been presented. The occurrence of odontogenic epithelium in the wall of dentigerous cyst is a well known entity. This epithelium usually remains inactive and does not have clinical significance, but these small inactive islands of epithelium may be stimulated, resulting in chronic inflammation, ameloblastoma and squamous cell carcinoma. Therefore correct diagnosis and proper treatment are very important. The authors have recently experienced a case of dentigerous cyst causing a mild disfigulation of face. The cyst was surgically enucleated through sublabial approach.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.437-444
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• 2015

Due to the attractive benefits with regard to bone health, digestion, and hydration, carbonated water consumption have rapidly grown over the past few years. However, the acidic drink has latent potential for enamel erosion. The most experimental studies about the enamel erosion have focused on the carbonated beverages with sugar and artificial sweeteners. Here, we determined the enamel erosion potential by commercially available carbonated waters with bovine teeth. The erosion was verified by pH value, calcium concentration, and scanning electron microscope. Then plaque accumulation by bacterial adhesion was determined on the enamel erosion surface to measure roughness. In the present study, we observed that the increased calcium content after being immersed in carbonated waters result from the overall enamel erosion. There were no significant differences between general carbonated waters and mineral waters for erosive capacity. Therefore, commercially available carbonated waters are potentially erosive. In addition, oral bacteria strongly adhered to the erosive enamel surfaces thereby facilitating the development of dental plaque. Thus, it is urgently necessary to provide food safety information on the carbonated water as acidic drink to prevent the enamel erosion.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.507-515
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• 2021

Objectives: The aim of this study was to evaluate the extent of the potential erosion of enamel induced by three different types of commercial fermented milk using the pH cycle model. Methods: Specimens were treated and soaked up in three types of fermented milk and in mineral water for 10 min, four times a day for 8 days, and all of the specimens were immersed in artificial saliva outside of treatment times. The microhardness of the surface was measured by a microhardness tester, and a scanning electron microscope (SEM) was used to identify the enamel surface morphology. Results: The differences in the surface microhardness (ΔVHN) of enamel were different among the groups (p<0.05). The four groups were in descending order of ΔVHN: the liquid type group, condensed-drink type group, condensed-stirred type group, and control group. The liquid type group had a higher ΔVHN than the other two fermented milk groups (p<0.05). Based on SEM observation, the most severe surface damage was due to the liquid type of fermented milk. Conclusions: Customers' careful discretion is advised when purchasing these types of fermented milk. This information is anticipated to be of much value in the prevention of dental erosion.