• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.316-322
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• 2001

Chemotherapy and radiotherapy used on pediatric oncology patients often causes dentofacial anomalies. Defects noted include tooth and root agenesis, root thinning, root shortening, localized enamel defect and maxillofacial underdevelopment. The effect of radiotherapy usually is confined to the radiation site but the effect of chemotherapy may be more wide spread becuase of its systemic distribution. Many pediatric cancers are treated with a combination of radiation and multiagent chemotherapy. Dental treatment affected by chemotherapy and radiation therapy damage to developing teeth and maxilloface includes retention of teeth, space maintenance, prosthetic considerations, requirements for oral hygiene. The following case related to multiple rootless teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.207-216
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• 2005

Mutans streptococci have been reported to be implicated in dental caries. Of these streptococcal species, Streptococcus mutans and Streptococcus sobrinus are most commonly found in human dental caries. Prevalence of these bacterial species in dental caries is found to be varied in different races and countries. Therefore, importance of these bacteria in dental caries remains to be determined. The present study was peformed to detect S. mutans and S. sobrinus in 52 Korean children with dental caries between 2 to 6 years of age. For the study, plaque samples were collected from caries-active(CA) and caries-free(CF) teeth of each subject. DNA was extracted from the plaques and amplified by polymerase chain reaction(PCR) using primers corresponding to dex and gtf genes. The results obtained from the study were as follows: 1. Of 52 children, 37 children (71.2%) were found to harbor S. mutans and/or S. sobrinus. 2. Of the MS-infected 37 children, 3 children (5.8%) harbored S. mutans and/or S. sobrinus in the CF plaques only, 22 children (42.3%) in the CA plaques only and 12 children (23.1%) in both CF and CA plaques. 3. S mutans and/or S. sobrinus were detected in 34 CA plaques (65.4%), while 15 in CF plaques (28.8%) 4. In the case of CF plaques, 8 plaques (15.4%) were observed to harbor S. mutans only, 6 plaques (11.5%) to harbor S. sobrinus only and 1 plaque (1.9%) to harbor both species. 5. Of CA plaques, 24 plaques (46.2%) were detected to have S. mutans only, 2 plaques (3.8%) to have S. sobrinus only and 8 plaques (15.4%) to have both species. 6. In comparison with the efficiency of two different primers for PCR, it was found that the primer based on gtf gene was more effective in detecting S. mutans, while the primer corresponding to dex gene was better for S. sobrinus. Overall results suggest that MS appears to be important in dental caries of the Korean children, and S. mutans is more closely associated with than dental caries as compared to S. sobrinus.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.205-215
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• 2008

The purpose of this study is to evaluate at which stage of tooth germ would develop into normal calcification and hence to increase the success rate of transplantation. Therefore, tooth germs on the 15th, 17th embryonic day and the 3rd day of birth were separated for allotransplantation into maxilla of adult rat of 11 weeks. Calcification processes were analyzed radiographically and histopathologically at 4 weeks and 8 weeks after allotransplantation. The results are as follows: 1. Allotransplanted tooth germ at 4 weeks and 8 weeks showed delayed calcification compared to that of normal odontogenesis. 2. At 4 weeks, abnormal calcified tissue, such as odontoma and ankylosis of osteodentin with surrounding alveolar bone were observed. 3. At 8 weeks, allotransplanted tooth germs of the 15th and 17th embryonic day showed calcification and osteodentin surrounded by periodontal ligament. 4. At 8 weeks, allotransplanted tooth germs of the 3rd day of birth showed calcification composed of cementum and osteodentin. In this study, we observed small sized and amorphous calcified tissue from allotropic allotransplantation of tooth germs. Since these calcified tissue were underdeveloped and shaped irregularly, for calcification into normal tooth form, further study needs consideration about the reduction of surgical trauma, developmental stage of transplanted tooth germ, blood supply from recipient site, fixation method in transplanted site and period of transplantation.

• Journal of Periodontal and Implant Science
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• v.20 no.2
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• pp.165-165
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• 1990

• The Journal of the Korean dental association
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• v.39 no.11 s.390
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• pp.926-935
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• 2001

• The Journal of the Korean dental association
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• v.42 no.11 s.426
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• pp.779-789
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• 2004

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.12.1-12
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• 1981

The dentigerous cyst originates through alteration of the reduced enamel epithelium after the crown of the tooth has been completely formed, with accumulation of fluid between the reduced enamel epithelium and the tooth crown. The dentigerous or follicular cyst comprises about 20% of all dental cysts. It usually occurs between 20 and 30 years of age but is occasionally seen in children or in old people. The most common sites of this cyst are the mandibular third molar and maxillary cuspid areas, since these are the most commonly impacted teeth. Many of these cysts give no clinical symptoms until noticeable asymmetry of the face develops. Rarely it develops to an ameloblastoma, epidermoid carcinoma and mucoepidermoid carcinoma, so early removal leads to better result. Roentgenographic examination of the jaw involved by a dentigerous cyst will reveal a radiolucent area. Recently the authors have experienced a giant dentigerous cyst which produced the bony deformity of the maxillary and hard palate bone. The cyst was completely removed under the local anesthesia by Caldwell-Luc approach.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.109-116
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• 2010

Impaction is defined as a cessation of the eruption of a tooth caused by a clinically or radiographically detectable physical barrier in the eruption path or by an ectopic position of the tooth. The reasons for impaction of the maxillary central incisor are supernumerary tooth, odontoma, ectopic position of tooth germ, dilacerated tooth and so force. Impacted tooth cause space loss due to proximal movement of adjacent tooth, malocclusion, root resorption of adjacent tooth, cyst formation, so careful observation and early detection is important and exact treatment should be applied to prevent these results. The treatment options of impacted tooth include induction an eruption through extraction of deciduous tooth or surgical exposure, reposition of impacted tooth by surgical method or orthodontic treatment. Orthodontic traction is recommended when an eruption does not happen after removal of barrier or surgical exposure, when eruption path is too transpositioned to be corrected spontaneously so eruption does not expected. In these cases, traction of impacted maxillary central incisor was carried out using orthodontic method with closed eruption technique and it showed good clinical results so we report these cases.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.89-95
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• 2001

Effects of application method of eight nematicides on reproduction of iweloidogyne arenaria were tested in pot. In pre-treatment, cadusafos , dazomet, fosthiazate reduced over 90% in number of egg masses of M. arenaria at recommended rate . Carbofuran showed similar reduction only at three times of recommended rate. Benfuracarb was the least effective. Post-treatments, in general, were less effective than pre-treatment except fostiazate which reduced root egg mass of iW. arenaria as much as pre-treatment at recommended rate . Systematic nematicide, fosthiazate has potential as post-treatment nematicide.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.81-93
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• 2013

The objectives were to evaluate the accuracy of shade selection by human visual system(VS) and 2 different colorimeters ($ShadeEye^{(R)}$(SE) and Shadepilot (SP)). Maxillary anterior teeth of 30 volunteers which had no caries or restorations were included in the study. Firstly, the accordance in shade selection by 3 dentists and 2 colorimeters was investigated. Secondly, the color of the teeth were measured by 1 observer's naked eye and 2 colorimeters under different illumination conditions (Sunny versus cloudy day). Additionally testing of inter-observer variability selected colors by 2 novice and 2 experienced dentists were compared. For comparing visual and 2 different colorimeters, SP(60%) showed significantly highest rate of accordance than the visual (23.3%) or SE (16.7%) and lowest mean ${\Delta}E$ ($2.62{\pm}0.74$ versus $3.83{\pm}1.38$;SE or $4.04{\pm}1.61$;VS)(p<0.001). If accuracy of shade selection were measured using VS, the mean ${\Delta}E$ value of cloudy day was higher than that of sunny day ($4.35{\pm}1.70$ versus $3.53{\pm}1.31$; p<0.001). There were no significant difference of the mean ${\Delta}E$ value between sunny and cloudy day in both SE and SP. Inter- observer repeatability was higher in 2 experienced group (73.3%) than novice group (36.7%). The mean ${\Delta}E$ of experienced group was lower than that of novice group ($3.60{\pm}1.47$ versus $4.70{\pm}1.67$; p<0.001). Colorimeters (SE or SP) is more accurate and more reproducible compared with human shade assessment. Using visual system may be limited by cloudy and inexperience of tester, then more experience and using colorimeters may be helpful of raising the accurate repeatability of shade selection.