• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.41-56
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• 2018

The purpose of this study was to provide clinical recommendations for restoration with selection of the most similar zirconia crown by 3-dimensional analysis of the shape of the maxillary primary central and lateral incisors in Korean individuals and prefabricated zirconia crowns. The average shape of the sound maxillary primary central and lateral incisors in 300 children was reproduced by 3-dimensional scanning. Zirconia crowns of 4 manufacturers (NuSmile $ZR^{(R)}$ Crown, Cheng $Crowns^{(R)}$, Kinder $Krowns^{(R)}$, and EZ $Pedo^{(R)}$ Crown) were scanned 3-dimensionally, and coordinates for comparison of the shape were measured to evaluate the similarity between the teeth and crowns. The most similar crowns were selected by comparing the mesiodistal length, crown height, crown shape ratio, distance between the same coordinates of a tooth and crown, the radius of curvature of the labial surface, and the volume. As a result of analysis, Cheng $Crowns^{(R)}$ size 3 and NuSmile $ZR^{(R)}$ Crown size 2 were the most similar crowns in the maxillary primary central and lateral incisors, respectively. Scanning the inner surface of the crowns and evaluating the amount of tooth reduction required suggested that an overall lesser amount of tooth reduction compared to that presented by the manufacturer's guidelines should be performed.

• Journal of dental hygiene science
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• v.16 no.5
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• pp.349-354
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• 2016

The purpose of this study was to evaluate the efficacy of the newly-developed $Qraypen^{TM}$ (All In One Bio, Korea) system for the diagnosis of early proximal caries by comparing it with the conventional methods of visual inspection and periapical radiography. This study was carried out from July 2015 to April 2016 targeting 32 children aged 7~12 years who visited Y-Dental Clinic for school oral health examinations. Two investigators selected and examined a total of 153 primary molars that had not undergone restorative treatment. Comparisons were carried out between visual inspections, readings of posterior periapical radiography images, and readings of $Qraypen^{TM}$ images. This study revealed that the percentage of interproximal surfaces of primary molar teeth without caries incidence was 83.7% using $Qraypen^{TM}$ imaging and 84.9% using visual inspection and periapical radiography. The differences between the two methods were not statistically significant. Thus, $Qraypen^{TM}$ is expected to be a useful and convenient auxiliary diagnostic device that can facilitate the detection of hidden proximal caries in primary molars.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.426-435
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• 2018

The aim of this study was to evaluate the proximal caries detecting ability and identify the optimal cut-off values of two types of laser fluorescence (LF) devices; classic type (DD) and pen type (DDpen). The number of proximal surfaces participated in this study were 164 surfaces in primary dentition and 438 surfaces in permanent dentition. Each tooth surface was sequentially assessed by two types of LF devices, and bitewing radiograph. The radiographs were classified into 3 groups in primary dentition ($pR_0$, $pR_1$, $pR_2$), and 4 groups in permanent dentition ($PR_0$, $PR_1$, $PR_2$, $PR_3$) according to the depth of caries, and used as gold standard. In primary dentition, the area under the curve (AUC) values of DD were 0.851 and 0.890, and those of DDpen were 0.883 and 0.917, respectively in enamel caries and dentin caries. In permanent dentition, the AUC values of DD were 0.762 and 0.886, and those of DDpen were 0.828 and 0.958, respectively in enamel caries and dentin caries. When detecting proximal caries in posterior teeth with LF devices, DDpen is more useful than DD in both primary and permanent dentition. However, in primary dentition, DD can also be useful to detect proximal caries.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.93-100
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• 2019

The objective of this study was to analyze the color distribution of the maxillary primary central incisors and the relationship between the color of each tooth region by dividing tooth into incisal, middle and cervical region using a spectrophotometer. The subjects were 105 sound maxillary primary central incisors from 3 to 6 years old children. Color measurements were performed by one dentist using same protocol. CIE $L^*$, $a^*$, $b^*$, $C^*$, $h^*$ data and the best matched shades with coverage error were obtained for each region and whole labial surface. There was a significant difference in CIE $L^*$, $a^*$, $b^*$ according to regions and the difference in color between each region was more than the clinical acceptance. By correlating the relationship between the color of each region with $L^*$, $a^*$, $b^*$ values, it is possible to extrapolate the color of other region with one color or to be used as data for making restorative materials and prostheses that are more aesthetically pleasing for primary teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.468-480
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• 2022

The purpose of this study was to evaluate the effect of interceptive primary canine extraction in palatally and buccally displaced maxillary permanent canines, and to analyze the clinical and radiographic factors affecting the treatment outcome. 97 maxillary permanent canines from 86 patients whose maxillary permanent canine were in the mesio-occlusal directions and overlapped with the roots of the adjacent teeth were analyzed. In 64 of 97 (66.0%) maxillary permanent canines, the displaced crown was completely deviated from the adjacent lateral incisor root only by extraction of the primary canine. Not only the characteristics of maxillary permanent canines such as bucco-palatal displacement direction, horizontal and vertical position of the crown tip, and presence of apical closure, but also periapical rarefaction on the primary canine and peg-shaped adjacent lateral incisor significantly affected the treatment outcome.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.108-118
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• 2010

Introduction: Maxillary posterior region, compared to the mandible or maxillary anterior region, has a thin cortical bone layer and is largely composed of cancellous bone, and therefore, it is often difficult to achieve primary stability. In such cases, sinus elevation with bone graft is necessary. Materials and Methods: In this research, 121 patients who had implant placement after bone graft were subjected to a follow-up study of 5 years from the moment of the initial surgery. The total survival rate, 5-year cumulative survival rate and the influence of the following factors on implant survival were evaluated; the condition of the patient (sex, age, general body condition), the site of implant placement, diameter and length of the implant, sinus elevation technique, closure method for osseous window, type of prosthesis and opposing teeth. Results: 1. The 5-year cumulative survival rate of total implants was 90.5%, there was no significant difference between sex, age, the site of implant placement, diameter and length of the implant, sinus elevation technique, and the type of opposing teeth. 2. Patients with diabetes mellitus < osteoporosis and smooth-surfaced machined group < hydroxyapatite (HA)-treated group and homogenous demineralized freeze dried allogenic bone (DFDB) bone graft only group had significantly lower survival rate. 3. With less than 4 mm of residual alveolar ridge height, lateral approach without closing the osseous window resulted in a significantly lower survival rate. 4. Restoration of a single implant showed a significantly lower survival rate, compared to cases where the superstructure was joined with several implants in the area. Conclusion: Patients with diabetes or osteoporosis need longer period of time for osseointegration compared to the normal, and the dentists must be prudent when choosing a surface treatment type and the bone graft material. Also, as the vertical dimension of the residual alveolar ridge can influence the result, staged implant placement should be considered when it seems difficult for the implant to gain primary stability from the residual bone with less than 4 mm of vertical dimension. It is recommended to obdurate the bone window and that the superstructure be connected with several impants in the peripheral area.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.91-95
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• 2009

The use of stainless steel crowns are indicated for restoration of primary or permanent molars with proximal dental caries, extensive dental caries, or previous pulp treatment with increased danger of tooth fracture. Stainless steel crowns were introduced by Humphrey in 1950. For their improved durability, longevity, and success rate, they have been strongly considered for restoring extensive and multi-surfaced dental caries of molars in pediatric dentistry. However, they also have shortcomings, such as possibility of pulpal exposure or damaging proximal surface of adjacent teeth. In addition, when oversized stainless steel crowns are used, eruption of the adjacent permanent teeth may be disturbed by their prominent margin. As a means to compensate the shortcomings of stainless steel crowns, use of orthodontics bands may be considered. It is an alternative restoration method, where an orthodontic band is placed on a tooth first and cavity is restored with filling material, such as composite resin, glass ionomer, or amalgam. The use of an orthodontic band is indicated for molar restoration with cervical dental caries, extensive dental caries, enamel hypoplasia, or previous pulp treatment. Because it requires shorter chair time compared to stainless steel crown, its application is very useful for children with poor behavior. However, restoration using an orthodontic band requires good oral hygiene after its application. This case report illustrates the conservative restoration of primary molars and permanent molars with extensive dental caries using orthodontic bands.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.248-256
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• 2020

This study aimed to evaluate the effects of national dental screening for children in Korea in the aspects of prevention of dental caries, the number of treatments related to dental caries, and cost of dental care. The study used the national cohort data on children health screening provided by National Health Insurance Service, and analyzed 32,937 1st dental screening, 22,608 2nd dental screening, 13,708 3rd dental screening, and 241,043 cases from the dental care of 27,944 children born in year 2008 and 2009. The decayed-filled teeth index and decayed-filled person rate, calculated from the results of the 2nd and 3rd dental screening, decreased as the number of preceding dental screening increased. Glass ionomer and amalgam restoration, pulp treatment of primary teeth and extraction of primary canine and molar were shown to decrease as the number of examined dental screening increased, and the total cost of dental care covered by national health insurance also decreased as the number of dental screening increased. In conclusion, national dental screening for children is an efficient and economical oral health care method that prevents dental caries and lowers the possibility of dental caries related treatment, thereby reducing cost of dental care.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.406-415
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• 2020

Silver diamine fluoride (SDF) is an effective and efficient agent for arresting dental caries. It can be useful in treating children with behavioral or medical limitations. The purpose of this study was to evaluate the antimicrobial effect of SDF by using salivary biofilm. Pellicle-like saliva coated structure was prepared by using unstimulated saliva. For developing cariogenic biofilm, Streptococcus mutans was added to the mixture of pooled saliva and inoculated into a saliva coated glass or chamber. SDF was applied to cariogenic biofilm to evaluate the antimicrobial effect of SDF. As time passed, total bacteria and S. mutans were reduced after application of SDF (p < 0.000). Confocal laser scanning microscope also showed the increment of the ratio of dead cell. As a result of experiment using enamel and dentin of primary teeth, it was confirmed that the growth of cariogenic biofilm was inhibited when the SDF was treated (p = 0.029 each). This study showed excellent anti-microbial effect of SDF. And anti-caries effect in clinical practice can be expected.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.14 no.1
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• pp.17-21
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• 2018

Williams syndrome (WS) is a rare congenital disorder which is caused by microdeletion of approximately 1.6 MBP from the long arm of chromosome 7 at 7q11.23. It is characterized by cardiovascular anomalies, elfin face and mental retardation. The most typical oral signs in patient with WS are hypodontia, reduced mesio-distal dimensions both in the primary and permanent teeth, macroglossia, excessive interdental spacing, enamel hypoplasia and enamel hypomineralization. The majority of children with WS have mild to moderate mental retardation, generalized anxiety disorder, hyperactivity disorder and sensitivity to sounds. The purpose of this presentation is to describe dental treatment for a child with WS. A 9-year-old boy diagnosed with WS had caries on his first permanent molars. Because of the poor cooperation, these teeth were filled temporarily with glass ionomer, and treatment under general anesthesia was planned. Under general anesthesia, caries treatment of first permanent molar and extraction of primary molar was successfully performed and there was no postoperative complications related to general anesthesia. Open bite, hypodontia, excessive dental space, enamel hypoplasia, enamel hypomineralization were observed which were characteristic in WS.