KJC Korea
Journal Central

Periodontal disease, one of the most common oral diseases, has been widely researched. However, in the face of increasing incidence of adolescent periodontitis, there has been only little concern about the periodontal conditions in adolescents. The purpose of this study was to evaluate the periodontal health and assess the prevalence of the periodontal disease and its causing factors among adolescents. The data was collected from subjects ranging from age 10, 13 and 16 years old in Jeonju by clinical examination and survey. The prevalence of periodontal disease and plaque index value were higher in male than female (p < 0.05). The group of 13 years old subjects had the highest prevalence of periodontal disease (73.3%) and plaque index value (p < 0.05). Among the plaque index of each individual tooth, mandibular central incisor showed the highest value. The survey relating anticipated risk factors demonstrated that the group of 13 years old subjects had the least care for oral hygiene. Also, patients who received the treatment of scaling exhibited high plaque index (p < 0.05), and adolescents with great stress loads showed calculus deposition and increased plaque index (p < 0.05).

This study aimed to identify the characteristics of jaw cysts among children and adolescents treated at the Kyung Hee University Dental Hospital from 2005 to 2015. A retrospective observational study was conducted of 269 jaw cysts diagnosed in 253 patients. The following variables were recorded: gender, age, prevalence and location of lesions, clinical symptoms and treatment. Statistical analyses were performed using the SPSS (version 20.0). Our results suggest that the cysts are slightly more prevalent in males. Cystic lesions of the jaws in children are predominantly odontogenic and developmental in origin. Dentigerous cysts predominate in developmental cysts and the most frequent diagnosis is radicular cysts in inflammation cysts. The most common location of the cysts is in the mandible, particularly the lower molar region. In numerous cases, the patients have no clinical symptoms. Most cysts were surgically enucleated with tooth extraction. Furthermore, our findings demonstrate that the characteristics of jaw cysts in children are distinctive and differ in several respects from the corresponding distribution of jaw cysts in adult population. Therefore, knowledge of the clinical, radiological and histopathological behavior of jaw cysts and periodic radiographic examination are key factors for early diagnosis and adequate treatment of jaw cysts in children.

The optimal time for the removal of supernumerary teeth can be divided into two groups; early removal and late removal. While each group has its own advantages, the effects on maxillary central incisor can be significant. The purpose of this study was to determine the ideal time for the removal of the supernumerary teeth by evaluating 166 patients for three months after surgical removal of supernumerary teeth. Relatively young patients in early Hellman’s dental stage with less developed or unerupted maxillary central incisor had less midline deviation. No statistical significance was found in diastema, rotation of the maxillary incisors and their changes during a follow-up period. Removal of supernumerary teeth should be considered as a preventative measure prior to eruption of the maxillary incisors when the midline deviation is observed in panoramic radiographic examination. This study will be useful in determining the optimal time for the removal of supernumerary teeth depending on the location of the maxillary incisors. This study will be informative on deciding the optimal time to remove the supernumerary teeth depending on the various positions of the maxillary central incisor. (this sentence is better to use)

Many studies on the prognosis of avulsed teeth were published but follow-up studies on Korean children and adolescents are insufficient. The aim of this study was to identify clinical factors determining the healing and prognosis of permanent incisors that were replanted after avulsion injury. This study included 184 permanent teeth in 142 patients aged 6-14 years. The clinical and radiographic data of the patients were analyzed from electronic medical records. Immature teeth had a higher probability of pulp revascularization than mature teeth. When extra-alveolar time was longer than 60 minutes, the incidence of inflammatory root resorption (IRR) was higher in immature teeth than mature teeth. However, the incidence of replacement root resorption (RR) was higher in mature teeth than immature teeth under the same condition. The incidence of IRR was increased when pulp was extirpated more than 20 days after replantation. IRR had a more significant influence on the decrease of survival expectation than RR. There was no significant correlation between the root development stage and survival expectation. However, when RR occurred, immature teeth survived shorter than mature teeth. Long term follow-up results from this study are expected to be used as fundamental data for the treatment guidelines and evaluation of the prognosis of replanted teeth.

It is a trend that carbonated drink intake among adolescents is increasing, which makes young people more vulnerable to dental erosion. However, in Korea, public knowledge about dental erosion is very insufficient. The aim of this study was to investigate the prevalence of dental erosion and to assess its risk indicators among 13- 15 years old students in Yangsan, Korea. A total of 1,371 adolescents were examined by one calibrated clinician. Dental erosion was assessed by using the Visual Erosion Dental Examination system. Correlation between their dietary habit, oral hygiene and dental erosion was assessed. The data showed that 676 (49.3%) adolescents had dental erosion. The prevalence of dental erosion was significantly higher in females than in males. The prevalence of tooth erosion in mandible is higher than in maxilla. Dental erosion was generalized to develop mostly on anterior teeth, especially lateral incisor, however, the severity score was highest in canines. Following questionnaire analysis, dental erosion was significantly associated with milk and flavored milk. No other associations were detected. The prevalence of dental erosion in this study is higher than those of previous reports. On the contrary to previously reported studies, the prevalence of dental erosion in females is higher than in males.

The aim of this study was to evaluate the surface characteristics of composite resins polished with two different polishing methods. 30 disk-shaped specimens were prepared with microhybrid (FiltekTM Z250) and nanofilled (FiltekTM Z350) resins respectively, and classified into three groups: not polished as controls, polished by an abrasive disk (Soflex), and polished by a polishing brush (Occlubrush). Surface roughness was increased after polishing. In terms of micro-roughness, there were no significant differences between the two polishing methods. But macro-roughness values were markedly increased in the Occlubrush group (p < 0.05). In the Sof-lex group, the matrix and fillers were polished together, resulting into a smoother and homogeneous surface. However, in the Occlubrush group, the matrix layer was torn off, with more heterogeneous surfaces and large scratches. In regards to micro-hardness, no significant differences were observed between the two polishing systems (p > 0.05). And the hardness value increased about 25% after polishing. In conclusion, the method of polishing should be chosen deliberately in view of the hardness characteristics of composite resins. Sof-lex is recommended to improve the surface characteristics of polished resins.

In order to provide a diagnostic basis for predicting the possibility of the self-correction of ectopic first permanent molars, differences among normal eruption, reversible and irreversible ectopic eruption of maxillary first permanent molars were retrospectively analyzed. The angles of the long axes and the occlusal lines between the maxillary first permanent molar and the adjacent tooth were measured by panoramic radiographs. The occlusal relationship of second primary molars was also investigated. There is a statistically significant difference between the ectopic eruption group and normal group (p < 0.05), but not between the reversible and irreversible ectopic eruption groups (p > 0.05). The angles between the second primary molar and the first permanent molar, the second primary molar and the second permanent molar in ectopic groups showed a smaller degree than those of the control group. Mesial step was found more frequently in the ectopic eruption group than the normal group. In conclusion, the angulation of the first permanent molar and tooth germ of the maxillary second permanent molar showed close relation with ectopic eruption of the maxillary first permanent molar and ectopic first permanent molar is likely to occur in class Ⅲ patients with maxillary deficiency.

The aim of this study was to compare the compressive strength and amount of fluoride-release of recently developed giomers (Beautifil Flow Plus F00, Beautifil Flow Plus F03), conventional giomer, resin-modified glass ionomer and composite resin. Fifteen cylindrical specimens for each group were prepared to measure fluoride release. It was measured using pH/ISE meter and fluoride ion electrode every 24 hours for the first 7 days and every 72 hours until the 31st day. Also, fifteen cylindrical specimens for each group after thermocycling were prepared to measure compressive strength. The universal testing machine (Kyung-sung Testing Machine Co., Korea) was used and the crosshead speed was 1 mm/min. Recently developed giomers showed more fluoride release and higher compressive strength than conventional giomer. It would be a good alternative to composite resin.

The aim of this study was to identify the causative genetic mutation in a family with non-syndromic oligodontia. The 7-year-old female proband and her mother underwent oral examination, panoramic radiographs were obtained and blood samples were collected. All exons of the PAX9 gene were amplified by polymerase chain reaction and sequenced. The sequencing results were compared with the standard human gene sequence. The proband lacked 11 permanent teeth, and her mother lacked 19 permanent teeth. No other birth defects were observed. As a result of gene analysis, there was a novel heterozygous nonsense mutation (c.184G>T, p.Glu62*) in exon 2 in both affected subjects. It is suspected that the nonsense mutation leads premature termination of translation, yields a truncated protein 280 amino acids shorter than the wild-type protein. These defects include parts of the paired box domain, a DNA-binding site that plays an essential role in protein function. Otherwise, more likely the mutant transcript would be degraded by nonsense-mediated decay system, resulting haploinsufficiency to cause oligodontia in this family.

Gargle solution has typically been used for the prevention of oral infectious disease such as dental caries and periodontitis. However, the use of most gargle solutions is controversial in application for children because some gargle solutions have harmful side effects. Electrolyzed water is generated by passed an electric current and has antimicrobial activity. The purpose of this study was to investigate and compare the efficacy of electrolyzed water in various conditions for eliminating cariogenic bacteria. Electrolyzed water was generated by a platinum electrode in the presence of sodium chloride at various concentrations. Streptococcus mutans and Streptococcus sobrinus were cultivated into a brain heart infusion broth. After harvesting planktonic bacteria, the pellets were treated with the electrolyzed water and commercial gargle solutions and plated on a mitis-salivarius agar plate. Also, the anti-biofilm activity of the electrolyzed water and commercial gargle solutions was investigated after biofilm formation of S. mutans and S. sobrinus. The bacteria in the biofilm were plated onto a mitis-salivarius agar plate. The plates were incubated, and the colony forming unit was measured. The electrolyzed water containing sodium chloride showed significant antibacterial activity against S. mutans and S. sobrinus as well as some gargle solutions. Furthermore, the electrolyzed water had more disruptive effect on the biofilm of S. mutans and S. sobrinus and killed more bacteria in the biofilm than commercial gargle solutions. The results demonstrate that electrolyzed water may be a useful gargle solution for prevention of dental caries.

Wolf-Hirschhorn syndrome (WHS), associated with the deletion of the short arm of chromosome 4, causes multiple congenital malformations. Patients suffer from various deformities, including mental and growth disorders, epilepsy, hypotonia, congenital heart defects, and atypical craniofacial features. The “Greek warrior helmet appearance”is the most characteristic feature, with a prominent glabella, high arched eyebrow, broad nasal bridge, and hypertelorism. Cleft lip with or without cleft palate is observed in 30% of patients. Dental structure anomalies also exist including multiple tooth agenesis and over-retained primary molars caused by MSX1 gene impairment, and coneshaped and taurodontic teeth. This case, a 9-year-old girl with WHS, showed intellectual disability, delayed growth development, previous occurrence of seizures, otitis media, and the typical facial features of WHS. Dental findings included multiple congenital missing teeth, over-retained primary teeth, and severe caries on the primary molars. Dental treatments were performed under general anesthesia. This report documents the characteristics of WHS, including general and oral features, and discusses the importance of oral hygiene and preventive dental management.

The fracture of a needle during local anesthesia in dental treatment is rare; however, when it occurs, the needle should be removed without damage to surrounding structures as soon as possible. A fractured needle fragment that is buried in soft tissue would be difficult to remove, and a careful surgical procedure under general anesthesia is recommended in such cases. Children who require dental treatment are often not capable of cooperative behavior, thus unexpected movements can increase the risk of needle fracture. Clinicians can reduce the incidence of needle fracture accidents with a few precautions. In the present case report, we report a case of needle fracture due to abrupt movement during inferior alveolar nerve block anesthesia in a young child, with the purpose of drawing attention to needle fracture incidents. This report describes the possible causes and prevention methods of local anesthetic needle fracture, and the localization methods and surgical procedure for needle fragment removal.

Tourette’s syndrome is a chronic neuropsychiatric disorder characterized by the presence of vocal and multiple motor tics. Tics are defined as brief, intermittent, repetitive, unpredictable, purposeless, and stereotyped movements or sounds. Some patients experience physical pain from intense and complex tics. In addition, motor tics can result in self-injury which is a common feature of Tourette’s syndrome. A 9-year-old boy was referred by the department of neuropsychiatry because of a severe tongue laceration. His parents reported that he had been biting his tongue irregularly for 2 months before referral and suffered from an intense burning sensation. The repeated biting resulted in ulcers on the tongue, which quickly worsened and led to progressive difficulty chewing and swallowing food. We offered to give him a two-piece removable appliance to limit tongue biting; it was made of soft silicone and fitted to both the maxillary and mandibular arches. As we emphasized that the device could help alleviate his pain, he agreed to accept it and adapted well. Just 3 weeks later, his tongue lesions had healed significantly.

Child abuse often interferes with the normal and healthy development of a child, bringing about various complications and problematic behaviors. Furthermore, such physical, mental abuse or neglect, and sexual abuse on a developing child may have serious effects even until after adolescence. The types of injuries caused by physical abuse vary, but some types of injuries are common. A great number of them can be detected during a routine dental examination because many of these injuries are present in the facial and dental region. Accordingly, in the case of abused children, it is important to find the signs of abuse through regular dental checkups, as many suffer injuries to the face, head and neck area including the oral and perioral area. As a pediatric dentist, it is the legal and social obligation to contribute to preventing and assisting the struggle against child abuse. The authors contemplate ways for all pediatric dental related personnel to find some clinical signs and symptoms of child abuse to help early detection, and to manage the situation properly.