KJC Korea
Journal Central

The aim of this study was to assess the spacing and crowding of the anterior teeth in the primary dentition in Hwaseong city. Photographs of the anterior segment of 237 children satisfied the criteria. The presence of primate spaces and developmental spaces was assessed by the proximal contacts. Physiologic spacing was observed in 47.3% and 38.0% of the cases in the upper and lower arches, respectively. 43.5% showed the presence of two-segment contact or crowded dentition. Physiologic spacing was observed more in boys than in girls. In the maxilla, primate space was more frequent than developmental space; however, in the mandible, the difference was low. In the maxilla, the space between the central incisor and the lateral incisor was more frequent than the space between both central incisors. In contrast, in the mandible, the space between both central incisors was more common than the space between the central and lateral incisors or between the lateral incisors and canine. The present study describes the tendency for anterior spacing and crowding in the primary dentition. Further longitudinal studies with a larger sample are needed. Dentists should consider these concepts of spacing or contact/ crowding when performing full coronal restorations of primary anterior teeth.

The purpose of this research is analyzing present condition, and pursuing developmental direction of consultation to department of dentistry for medical inpatient with dental trauma. This research conducted a retrospective analysis of consultation to department of dentistry for medical inpatient at Wonju Severance Christian Hospital from March 2011 to February 2017. This research analyzed chief complaint and dental diagnosis, referring department, time of consultation after dental trauma, relation between hospitalization period and time of consultation after dental trauma, relation between dental trauma and admission in the medical department due to trauma, cause and age of dental trauma occurrence, treatment of dental trauma, and revisiting rate of inpatient with dental trauma after discharge. Among all the chief complaint and dental diagnosis, dental trauma was the highest. Among all the referring departments, departments of surgery were the highest. In relation to being delayed of consultation term after dental trauma, it turned out that there’s pretty high mutual relation between the hospitalization period and the consultation term after dental trauma, and the hospitalization period had the quantitative influence on the consultation term. Statistically, dental trauma and admission in the medical department due to trauma had significant relations. In case of those patients due to car accidents, they had dental trauma without exception. Statistically, patient’s group with dental trauma in hospital room was younger than patient’s group with dental trauma in non-hospital room. Statistically, dental trauma and treatment in hospitalization had no significant relations, and dental trauma and revisiting department of dentistry after discharge had no significant relations. For the child and adolescent inpatients hospitalized for car accidents, there is high possibility of accompanying dental trauma, and dental consultations can be delayed. For the young child inpatients, the possibility of dental trauma occurrence in hospital room is high. Moreover, treatments during hospitalization and revisiting department of pediatric dentistry after discharge are not performed well for inpatients with dental trauma. Regarding these results, it can be an alternative that improving of consultation system, dedicated workforce placement and having dental facilities and equipment in the hospital ward, education to medical doctor and dentist, communication between medical doctor and dentist. This research can be used as a study material of medical and dental departments, and it’s expected to be committed to developing of consultations to department of dentistry for child and adolescent inpatients with dental trauma.

During orthodontic treatment, formation of white spot lesions (WSLs) around brackets has long been recognized as a potential risk. This study performed to investigate effect of preventing enamel demineralization and remineralization by application of fluoride-containing orthodontic primer. Fifty extracted bovine incisors teeth were randomly allocated to 3 groups: (I) Non-preparation specimens, (II) Application of Light Bond™ as fluoride containing orthodontic primer, (III) Application of Transbond™ XT Primer as traditional orthodontic primer without fluoride. Each group is demineralized under artificial carious solution. The demineralization pattern was evaluated using a Q-ray view, Vickers hardness test and polarized light microscope. The remained primer was calculated as 35 - 50%. The highest surface microhardness was shown on Light Bond™ surface. There were statistically significant differences in Vickers microhardness number between adjacent areas of Light Bond™ and non-prepared area. There was almost no demineralization of the enamel surface under the Light Bond™. At the adjacent site of Light Bond™, the shallow caries pattern and remineralization appearance were also observed. These results suggest that the use of fluoride-containing primers may be useful for bracket attachment to reduce enamel demineralization during orthodontic treatment.

Attachment of the orthodontic bracket conducted during the window opening procedure can result in failure due to various adverse conditions such as blood or saliva contamination, or other wet conditions. For the success of the bracket attachment, reduction of total operation time is crucial. The purpose of this literature is to evaluate the differences between the final resultant shear bond strength of the conventional method of using phosphoric acid and self-etching primer, and that of the operation time-reduced method in which the curing step is omitted subsequent to the primer application. A total of 40 human maxillary incisors were prepared. Group Ⅰ(control group) and Ⅱ were etched with 37% phosphoric acid and Group Ⅲ and Ⅳ were conditioned with self-etching primer. Attachment of the group Ⅰ and Ⅲ was conducted by manufacturer’s instructions. The operation time of Group Ⅱ and Ⅳ was reduced by eliminating the curing step after the primer application. The resultant shear bond strength of each group was measured and an adhesive remnant index (ARI) was recorded. The mean shear bond strength of group Ⅰ, Ⅱ, Ⅲ, and Ⅳ were 14.16 MPa, 8.33 MPa, 8.29 MPa, and 6.48 MPa respectively. Significant differences could only be found between the control group and the experimental groups (p < 0.05). The ARI indicated no significant difference among all groups.

The purpose of this study was to examine guardian’s attitudes toward behavior guidance techniques used in pediatric dentistry. In this study, 117 guardians participated and the several behavior guidance techniques being used during actual pediatric dental treatment were explained to the guardians prior to writing a questionnaire. The behavior guidance techniques explained were: tell-show-do, voice control, protective stabilization by device, protective stabilization by staff, nitrous oxide sedation, sedation, and general anesthesia. For analysis, 106 completed survey forms were selected. Tell-show-do was rated as the most acceptable technique, followed (in order of decreasing acceptance) by: voice control; protective stabilization by staff; nitrous oxide sedation; protective stabilization by device; sedation; general anesthesia. Acceptance of each behavior guidance technique was not related to guardian age, gender, patient age, patient gender, patient dental experience, type of visit, and position of doctor. Within the limit of this study, the communicative guidance techniques (tell-show-do, voice control) were more acceptable than advanced behavior guidance techniques (protective stabilization, sedation, general anesthesia). The acceptability of general anesthesia was the lowest. The results of this survey may contribute to maintain optimal dentist – guardians communication in pediatric dentistry.

The aim of this study was to investigate the effects of green tea, black tea, barley tea and roasted corn tea used in South Korea to make tea on the formation of Streptococcus mutans biofilm. The aqueous samples of 4 types of tea were extracted from commercial tea bags using cold water (7℃) or hot water (72℃). S. mutans UA 159 was introduced into 96-well plates which contained the tea samples and 1% sucrose media. Crystal violet staining was used to assess the effects of teas on S. mutans biofilm formation. In both groups of green tea and black tea, the biofilm significantly decreased with the solution of 50 μL aqueous sample in 200 μL media and 100 μL aqueous sample in 100 μL media (p < 0.05). S. mutans biofilm with 25 μL of barley tea or roasted corn tea aqueous sample in hot water (72℃) for 10 minutes showed significant decrease compared of green tea or black tea (p < 0.05). In this study, green tea and black tea suppress the formation of S. mutans biofilm.

Recently, there have been many studies on bulk-fill resin composites. However, studies on the proper materials for pediatric patients are rare. The aim of this study was to compare the cavity wall adaptation of bulk-fill resin composites with conventional resin composite in class II cavities of primary molars using microcomputed tomography (micro-CT). Standardized class II slot cavities were prepared in 80 exfoliated primary molars and randomly divided into 4 groups. The control group was restored with conventional resin composite, Filtek Z-350 XT (FZ), and the three groups were restored with bulk-fill resin composites, Filtek bulk-fill posterior (FB), Tetric N-Ceram Bulk Fill (TNC), Filtek bulk-fill flowable (FBF). All specimens were thermocycled and then immersed in 50% silver nitrate (AgNO3) solution. Micro-CT was used to measure the penetration volume of the total silver nitrate and the degree of cervical marginal leakage and the number, size, and position of the voids were evaluated. The results revealed that the volume of silver nitrate were significantly different between FB and FZ (p < 0.05). The results also revealed that the penetration length of silver nitrate FBF showed statistically lower than the FZ and FB p( < 0.05). There was no significant difference between the groups in number and size of voids. In conventional resin composite, most of the voids were present inside the restoration (83.3%), but the voids in the bulk-fill resin composites incidence were higher in the gingivoaxial angle. The cavity wall adaptation demonstrated in class II restorations of primary molar by new bulk fill resin composites was similar to conventional incremental technique. Bulk-fill resin composites might be an clinical option for a faster restoration in deciduous teeth.

Stevens-Johnson syndrome (SJS), an extremely severe acute hypersensitivity reaction, causes extensive necrosis on the skin and the mucous membrane. SJS is a disease of unknown cause that can occur in all age groups. It is thought to be caused by drug allergy or induced by bacterial infection. Epidermal surface invasion of less than 10 percent is called SJS, and invasion of more than 30 percent is called toxic epidermal necrolysis. Although it is rare with an incidence of 1 - 2 cases per million people per year, it has effects on tooth development and therefore on children who are in a growth phase. The purpose of this case report is to examine the effect of SJS on tooth development in children. In general, eruption of the upper and lower 1st molars and lower central incisors starts at 6 - 7 years of age. Root development also occurs at this time. In the case reported here, SJS occurred in a 6-year-old patient. Although the patient's SJS was completely cured , he still suffers from aftereffects. Developmental abnormalities in the patient’s teeth were observed only in teeth for which root development had been completed at the time. The purpose of this case report is to illustrate how to diagnose such systemic diseases by intra-oral features and to recognize and resolve tooth development problems associated with the disease.

Autotransplantation of teeth with complete roots is being increasingly performed for orthodontic treatment or for replacement of unsalvageable teeth, but this procedure has lower survival and success rates than those obtained following transplantation of teeth with incomplete root formation. While previous autotransplantation procedures used only models of the donor tooth and recipient site, surgical guide templates created using 3D-printing technology are now available. They allow shaping of the recipient site in proper direction and to the correct depth, thereby reducing the treatment time and improving the success and survival rates. Herein, we report a case involving autotransplantation of a tooth with complete roots at the site of a congenitally missing permanent tooth using surgical guide templates generated with 3D-printing technology. The procedure resulted in favorable healing of the transplanted tooth.

Peripheral giant cell granulomas (PGCGs) are reactive, exophytic gingival growths, caused by regional irritation and chronic trauma. PGCGs are diagnosed through histopathologic evaluations and appear analogous to other soft tissue lesions. This report presents the case of a PGCG associated with the ectopic eruption of a maxillary central incisor. Following an excisional biopsy, the patient healed fully without recurrence for at least 1 year.