KJC Korea
Journal Central

The aim of this study was to identify the association between candidiasis and early childhood caries and to investigate whether the experience of candidiasis or oral candidiasis before age 1 can be considered as a risk factor for early childhood caries. The database used in this study was provided by Health Insurance Review and Assessment Service. Medical records of children born from January 2010 to December 2012 were obtained, and those without dental records were excluded. Subjects were divided into several groups based on the experience of candidiasis or oral candidiasis before age 6: candidiasis group and non-candidiasis group; oral candidiasis group and non-oral candidiasis group. Another categorization was done according to the experience of candidiasis or oral candidiasis before age 1. The incidence rate of early childhood caries in each group were compared. The prevalence of dental caries in children who have been diagnosed with candidiasis or oral candidiasis before age 6 was significantly different from those who have not experienced candidiasis. Similarly, children who have suffered from candidiasis or oral candidiasis before age 1 had significantly different incidence of caries from the children without candidiasis experience.

The primary maxillary second molars usually have three roots. However, an additional root located mesiopalatally is occasionally observed. This study aimed to determine the relationship between a mesiopalatal root of primary maxillary second molars and an abnormal eruption pattern of maxillary second premolars. The study was performed on cone beam computed tomography images taken from 916 children who visited the Dental Hospital of Kyung Hee University from 2010 to 2018. 744 serial cross-sectional cone beam computed tomography images were evaluated. The overall incidence of the mesiopalatal root of primary maxillary second molars was 3.2% (n = 24) and the abnormal eruption pattern of maxillary second premolars was 19.2% (n = 143). Especially, patients with the mesiopalatal root of primary maxillary second molars were significantly more likely to have the abnormal eruption pattern on maxillary second premolars (p = 0.000). The odds of the abnormal eruption pattern of maxillary second premolars with the mesiopalatal root of primary maxillary second molars was about 13 times higher than those without. The eruption pattern of the permanent successor should be carefully observed and treated if the mesiopalatal root of primary maxillary second molar is existent.

The aim of this study was to evaluate the association between various predicting tools and Apnea-Hypopnea Index (AHI) to identify children with sleep disordered breathing (SDB). From 5 to 10 years old who came for orthodontic counseling, 61 children, whom had lateral cephalograms, pediatric sleep questionnaire (PSQ) records, and portable sleep monitoring results, were included in this study. A total of 17 measurements (11 distances and 6 angles) were made on lateral cephalograms. The measurements of lateral cephalograms, PSQ scales and portable sleep monitoring results were statistically analyzed. 49 of 61 (80%) patients showed AHI > 1, which suspected to have SDB and their mean AHI was 2.75. In this study, adenoid size (A/N ratio), position of the hyoid bone from mandibular plane, gonial angle, and PSQ scale were related to a higher risk of pediatric SDB. Also, oxygen desaturation index (ODI) and snoring time from sleep monitoring results were statistically significant in children with SDB using Mann-Whitney test (p ＜ 0.05). In conclusion, evaluation of hyoid bone position, adenoidal hypertrophy, gonial angle in lateral cephalogram, and PSQ scale was important to screen out potential SDB, especially in children with frequent snoring.

A pyramidal molar is which has completely fused roots with a solitary enlarged canal. The purpose of this retrospective study was to assess the prevalence and characteristics of pyramidal molars among adolescent. A total of 1,612 patients’ panoramic radiographs were screened. A total of 12,896 first and second molars were evaluated. The relative incidence and the correlations regarding the location of pyramidal molar (maxillary versus mandibular) and gender were analyzed using the chi-square test. The overall incidence of patients with pyramidal molars was 1.49%. 24 patients were found to have a pyramidal molar and it was more prevalent in women (18 women and 6 men). The prevalence of pyramidal molars from all first and second molars examined was 0.31%. 88 percent of pyramidal molars occurred in maxilla. All pyramidal molars were second molar. Pyramidal molar has a relatively poor periodontal prognosis compared with common multi-rooted teeth and it is important to understand the structural characteristics of root canal during pulp treatment. Clinicians should be able to understand the anatomical properties of pyramidal molar and apply it to treatment and prognostic evaluation.

The aim of this study is to compare cariogenic characteristics of fluoride-sensitive Streptococcus mutans [fluoridesensitive (FS) S. mutans ] and fluoride-resistant Streptococcus mutans [fluoride-resistant (FR) S. mutans] in the presence of sucrose, and to evaluate its effect on cariogenic biofilm formation. S. mutans ATCC 25175 was continuously cultured in trypticase soy broth (TSB) containing NaF (70 ppm) for 40 days to generate FR S. mutans . FS and FR S. mutans were inoculated in TSB with or without 2% sucrose, and optical density and pH were measured every hour. An oral biofilm was formed using saliva bacteria and analyzed through confocal laser scanning microscopy and CFU count. Finally, the expression of glucosyltransferases genes of both S. mutans was investigated through RT-PCR. FR S. mutans exhibited slower growth and lower acidogenicity in the presence of sucrose compared to FS S. mutans . Both cariogenic and single species biofilm formation was lower in the presence of FR S. mutans , along with reduced number of bacteria. FR S. mutans showed significantly low levels of gtfB, gtfC, and gtfD expression compared to FS S. mutans . On the basis of results, FR S. mutans may be less virulent in the induction of dental caries.

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 purpose of this study was to calculate uncertainty of orthodontic measurement in skeletal class III malocclusion children using lateral cephalometry analysis software which obtained traceability in previous study. Using this data, standard reference of measurement value for skeletal class III malocclusion was obtained. Lateral cephalometric data was collected from 144 children who visited Pediatric Dentistry from 2017 to 2020 for orthodontic treatment. Orthodontic measurement was analyzed with software which obtained traceability. Type A evaluation of uncertainty and type B evaluation of uncertainty was calculated to obtain combined standard uncertainty and expanded uncertainty. Standard reference of skeletal class III children was compared to standard reference of skeletal class I children. Distribution range for skeletal class III malocclusion children aged 6 to 10 with 95% confidence interval was provided using calculated uncertainty of orthodontic measurement value.

The purpose of this study was to investigate the effects of public preventive dental healthcare services named the “Dental Preventive Health Services for Children” (DPHSC) on oral health-related quality of life (OHRQoL) in Korean children. Of the total 20,802 beneficiaries in 2018, 110 10-year-old elementary school students were randomly selected and were requested to complete a survey using the Korean version of Child Oral Health Impact Profile (COHIP) questionnaire before and after participating in DPHSC. Overall, 107 participants completed the pre- and post-survey. COHIP scores and clinical results such as numbers of decayed and missing teeth, malocclusion, and oral hygiene status from dental examination were statistically analyzed and the reliability and the validity of the responses were verified. There was a significant clinical increase in mean overall COHIP scores following DPHSC (p < 0.001, effect size 1.05). Children with decayed and missing teeth demonstrated poor OHRQoL. In conclusion, DPHSC can improve the OHRQoL of 10-year-old children.

Taurodontism is an anomaly characterized by a long and broad pulpal cavity and consumed apical location of the furcation area. This study aimed to determine the prevalence of taurodontism in deciduous molars based on digital panoramic radiographs of children. The study was performed on a sample of panoramic radiographs taken from 2,473 Korean children who visited the department of pediatric dentistry, Yonsei University Dental Hospital between Nov. 2005 and Mar. 2018. Taurodontism was mainly categorized by Daito’s method. Using panoramic radiographs, taurodontism was also categorized into mesotaurodontism, hypotaurodontism, and hypertaurodontism. Mesotaurodontism was the most prevalent type. A total of 2,473 panoramic radiographs were evaluated. The prevalence of taurodontism was 5.7% in general, 51.5% in the left quadrant, 48.5% in the right quadrant, 6.3% in the maxilla, and 93.7% in the mandible. The distribution of taurodontism stratified by gender showed a higher prevalence in males. This is a comprehensive study on the prevalence of taurodontism in children using the largest sample size to date.

The purpose of this study was to evaluate the effect of Indocyanine Green (ICG) and near-infrared (NIR) diode laser on Streptococcus mutans biofilms depending on ICG concentrations. S. mutans biofilms were formed on a Hydroxyapatite disk, and 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solutions dissolved in sterile distilled water and a NIR diode laser having a power of 300 mW and a wavelength of 808 nm were applied to the biofilms. The temperature changes of the biofilm surface according to the concentrations of the ICG solution were measured using a 1-channel thermocouple thermometer. Compared to the control group, in the groups with only the 3.0, 4.0, 5.0 mg/mL ICG solution application, and in the groups with the 1.0, 2.0, 3.0, 4.0, 5.0 mg/mL ICG solution application and light irradiation, a statistically significant decrease in the bacterial counts were observed. The temperature increase according to the concentration of the ICG solutions was 9.53℃, 10.43℃, 11.40℃, 12.10℃, 12.67℃, and 13.63℃ in ICG solutions of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 mg/mL respectively. This study presents the potential for clinical application of ICG and NIR diode lasers as a new method for preventing dental caries.

Proper treatment of an impacted tooth is required as it causes functional and esthetic disharmony, as well as it can cause root absorption of adjacent teeth. Treatment options for impacted teeth include periodic observation, surgical exposure, orthodontic traction followed by surgical exposure, tooth transplantation, and extraction. Modified Nance appliance, used for orthodontic traction, is clinically useful because it does not require patient cooperation. Through orthodontic traction combined with surgical exposure of impacted maxillary incisors, canines, and molars using modified Nance appliance, adequate results can be obtained.

Epidermoid cysts are rare benign lesions in the oral cavity that may be either congenital or acquired. The cysts are usually slow-growing and asymptomatic until becoming secondarily infected or large enough to interfere with mastication and speech. Consequently, diagnosis is often delayed. The condition is also uncommon in newborns and infants. Most of the lesions occur in the floor of the mouth and rarely in the upper lip. This report describes the case of a 29-month-old girl with a palpable mass in the inner mucosa of the upper lip. The lesion was surgically enucleated using an intraoral approach and histopathologically diagnosed as epidermoid cyst.