• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.256-261
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• 2004

Pulp canal obliteration(PCO) is seen commonly in dental pulp after traumatic tooth injuries and is recognized clinically as early as 3 monthly after injury. Pulp canal obliteration is characterized by deposition of hard tissue within the root canal space and yellow discoloration of the clinical crown. Opinion differs among practitioners as to whether to treat these cases upon early detection of PCO or to observe them until symptoms or radiographic signs of pulpal necrosis are detected. PCO may make root canal treatment necessary because of the development of apical periodotitis or for cosmetic reasons. If carefully executed, root canal treatment in teeth with an PCO is hightly successful and may act as a basis for internal bleaching. During a game, a 12-year-old girl was hit in the face. At that time, she was diagnosis a subluxation of the maxillary right central incisor. At the 24-month recall examination, a root canal of the tooth had been calcified and discolored gradually. We performed endodontic treatment to prevent perfect pulp canal obliteration and internal bleaching.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.136-143
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• 2004

The purpose of this study was to investigate the relationship between morphology and position of deciduous double teeth, and the occurrence of other dental anomalies in the same subject. Four morphological types were indentified according to Ailing's classification: type I, bifid crown-single root; type II, large crown-large root; type III, two fused crowns-single root; type IV, two fused crowns-two fused roots. Fifty-four double teeth were found in a total of 1,803 children, who had visited Wonkwang university hospital for dental treatment from January 1, 2003 to September 30, 2003. All of these children were examined clinically and intra-oral radiographs were taken. The results were as follows; 1. 49 children(2.7%) had more than one double teeth, 5 of these children had two double teeth on the bilateral side. And one child showed triple teeth which has three crowns and three roots. 2. Double teeth were predominantly situated in the anterior region, with a preference for the mandible. The ratio of cases involving central incisor and lateral incisor was higher than other cases. 3. There were 25 cases(46.2%) of missing successors among 54 cases of the double teeth. And, prevalence of the missing teeth was highest in the cases involving maxillary central incisor and lateral incisor. 4. In the case of type II(large crown-large root) had more missing successors.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.51-55
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• 2011

Supernumerary teeth are dental abnormalies in the permanent dentition and the primary dentition. The etiology is unclear, but it may occur due to dichotomy of the tooth bud or hyperactivity of dental lamina. They occur more in the permanent dentition than in the primary dentition, with the most common site being the premaxillary area. Supernumerary teeth can be classified by morphology and position. Supplemental tooth refers to normal shape tooth. The treatment of supernumerary teeth depends on its shape, position, effect on dentition, and child's physiological condition. In this case, supernumerary primary tooth in the maxillary molar area was revealed by radiographical and clinical examination, but it was difficult to determine which is the supernumerary tooth. The tooth on the mesial side was extracted to induce the formation of adequate space and to prevent excessive space loss, and the result was favorable.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.17-24
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• 2011

The aim of this study was to assess the outcome of MTA apexification in young permanent anterior teeth. Among the patients with the traumatized permanent incisors which were treated with MTA apexification, the dental records and radiographs were examined only for the patient who had follow-up examination at least 3 months after the treatment. Forty nine patients with 64 teeth were included in this study. Demographic information, location and type of teeth and periodontal injury, pre-treatment periapical lesion, clinical symptoms, status of MTA filling, healing of apical lesion and apical barrier formation after treatment were investigated. The outcome based on clinical and radiographic criteria were assessed. The results were as follows 1. Of 64 immature permanent incisors with MTA apexification, the clinical and radiographic success rates were 89.1% and 73.4%, respectively. 2. The maxillary incisors showed significantly higher success rates than the mandibular incisors. 3. There was no statistically significant difference in success rates among the teeth with different types of teeth and periodontal injury. 4. The status of MTA filling did not influence the clinical and radiographic success.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.376-382
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• 2011

In clinical dentistry, it is not difficult to meet the permanent first molars with severe coronal caries lesions in children or adolescents. The circumstances surrounding the first molars of children and adolescents are so immature and imperfect compared with those of adults. So we thought it significant to understand the status of these teeth at the moment of endodontic treatment and immediate cause of it. 106 patients with 135 permanent molars necessitating endodontic treatment in childhood and adolescence were included in this study, and the dental records and radiographs were examined. 1. The mean age was 11.9 year (male 11.5, female 12.5) and the result shows significant difference between gender(p<0.05). The mandibular teeth took more than half percentage than maxillary teeth. 2. Of 135 teeth, 45.2 percent of teeth had history of dental treatment previously and 16.3 percent of teeth showed necessity of re-endodontic treatment. 3. Of 73 teeth, 22 teeth had mesial-wall cavity causing endodontic treatment, 39 had occlusal cavity, and 12 had distal cavity.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.1
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• pp.48-52
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• 2013

Ectopic eruption of the first permanent molar is an abnormal positioning of this tooth, causing a premature resorption of the distal surface of the second primary molar. It occurs in approximately 3~4% of the population and the maxillary arch is usually affected. While 66% of ectopically erupting permanent molars are corrected spontaneously without treatment (i.e. a reversible type), active treatment is necessary for irreversible ectopic eruption cases. The treatment modalities have been divided into two categories: interproximal wedging and distal tipping. Interproximal wedging is indicated for minimal impaction and when the impaction is severe, distal tipping techniques are required. Although much has been written about treatment modalities on unilateral ectopic eruption of the first permanent molar, few reports mention bilateral ectopic eruption cases. In this report, two cases of bilateral ectopic eruption of the first permanent molars in young patients are presented. We describe the use of a modified bilateral Halterman appliance for correction of these cases and the clinical results were satisfactory.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.1-13
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• 2012

Short implants are used in parts which have anatomical structures like maxillary sinus, inferior alveolar nerve and limited alveolar height due to severe alveolar bone resorption. In these case, there are no need of additional bone augmentation so there are advantages like reduced entire treatment time, reduced patient's discomfort and protection of important anatomical structures. The aim of this study is, in implants whose length is less than 10mm, to analyze the impact of implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting on survival rates and marginal bone resorption. The samples used in this study were 227 implants, less than 10mm, placed in 137 patients in Wonkwang university dental hospital implant center. From dental charts the information about implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting were obtained. Emago advanced v5.6(Oral diagnostic systems, Amsterdam, The Netherlands)program was used to measure the amount of marginal bone resorption. Out of total 227 implants, resulting in 96.5 % of survival rate. There was a tendency toward higher failure rates for the maxilla and bone graft site. No significant difference in marginal bone resorption was found associated with length of implants(p>0.05) and neither with the diameter of implants. Among the risk factors examined, more failure rates of short implants can be attributed to poor bone quality in the maxilla and presence of bone graft. At implants under 10mm, length, diameter, location of implant placement, bone graft and splinting of prosthesis didn't affect marginal bone loss.

• The korean journal of orthodontics
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• v.48 no.3
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• pp.182-188
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• 2018

Objective: This study was performed to validate the autonomous maximal smile (AMS) as a new reference for evaluating dental and gingival exposure. Methods: Digital video clips of 100 volunteers showing posed smiles and AMS at different verbal directives were recorded for evaluation a total of three times at 1-week intervals. Lip-teeth relationship width (LTRW) and buccal corridor width (BCW) were measured. LTRW represented the vertical distance between the inferior border of the upper vermilion and the edge of the maxillary central incisors. Intraclass correlation coefficients (ICCs) for reproducibility, and the m-value (minimum number of repeated measurements required for an ICC level over 0.75), were calculated. Results: LTRW and BCW of the AMS were 1.41 and 2.04 mm, respectively, greater than those of the posed smile (p < 0.05), indicating significantly larger dental and gingival exposure in the AMS. The reproducibility of the AMS (0.74 to 0.77) was excellent, and higher than that of the posed smile (0.62 to 0.65), which had fair-to-good reproducibility. Moreover, the m-value of the AMS (0.88 to 1.05) was lower than that of the posed smile (1.59 to 1.85). Conclusions: Compared to the posed smile, the AMS shows significantly larger LTRW and BCW, with significantly higher reproducibility. The AMS might serve as an adjunctive reference, in addition to the posed smile, in orthodontic and other dentomaxillofacial treatments.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.403-409
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• 2013

The purpose of this study was to evaluate the correlation between caries experience, Quantitative Light-Induced Fluorescence-Digital (QLF-D) redings and new caries activity test (Cariview) results in preschool children. Fifty-seven healthy kindergarten children (male 28, female 29) were participated this study. The calibrated dentist investigated the caries experience of children and new caries activity test. Cariview samples were incubated in the activated medium at $37^{\circ}C$ for 48 hours. All QLF-D taking and readings were performed by one experienced and trained operator under identical conditions in a dental unit chair located in a darkened room. Analysis range was limited to the maxillary and mandibular anterior teeth. QLF-D redings (white spot and dental plaque) were analysed using QLF system. The dft index had a relatively high correlation with the QLF-D redings (white spot: r=0.617, simple plaque score: r=0.500) (p<0.01). Also, there was significant correlation between dft index and the Cariview score (r=0.286) (p<0.05). However, the Cariview score had no significant correlation between dt index and ft index (p>0.05). QLF-D can be evaluated objectively the initial caries lesions and dental plaque correlated with caries experience. Therefore, QLF-D will be useful to the study of caries prediction.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.226-231
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• 2015

The purpose of this study was to evaluate the accuracy of model according to three types of dental scanner. A maxillary acrylic model was prepared and duplicated 10 times by silicone impression materials. Corresponding working casts were formed from scannable stone and got a 3-dimensional digital models using three different scanners. The distance of each measurement region was measured using vernier calipers and the respective program. One-way ANOVA and the Tukey honestly significant difference post hoc test (${\alpha}=0.05$) was performed using IBM SPSS Statistics 21.0. Overall, the stone cast is smaller than the digital models in measurement distance. And measuring point value of laser scanner showed the most similar values and measurement points value of digital vernier calipers. Digital model of white light scanner showed similar values in the measurement points value of the blue light scanner. In conclusion, the laser scanner showed the best accuracy among the three types of dental scanner. However, the difference between the digital models and the stone cast can be accommodated in making prostheses. Thereby, three types of dental scanner are available in a clinically acceptable range.