The first permanent molars play a key role in maxillofacial development and occlusion. The purpose of this study is to investigate the characteristics and development stages of first molars with delayed eruption, and to evaluate their associations with congenital missing teeth. Eight-year-old patients who had delayed eruption in their first molars were classified into 75 patients with physical barriers and 77 patients without physical barriers. The development stages of the first and second molars in the delayed area were analyzed using Nolla method from the panoramic radiographs. The relationship between congenital missing teeth and delayed area was also investigated. Delayed eruption of first molars were more common in the maxilla alone. With the presence of physical barriers, male patients showed higher frequency in unilateral cases, while female patients had higher bilateral cases when there was no physical barrier. Delayed development of first molars were observed in delayed eruption area. In the absence of physical barriers, adjacent second molars were also developed slowly and the incidence of congenital missing teeth was high in delayed area. If first molars with delayed eruption are observed, clinical and radiographical follow-ups are necessary for the evaluation of their developmental stages and congenital missing teeth.

This study aimed to investigate a quantitative analysis of the anatomical characteristics of the maxillary supernumerary lateral incisor and its relationship with lateral incisors. Forty-four supernumerary lateral incisors from 43 patients were evaluated for analyzing the position, shape, direction, and relationship between the supernumerary lateral incisor and the normal lateral incisors, using cone-beam computed tomography (CBCT). To compare the size of crown, the mesiodistal width was measured and the Nolla stage was used for evaluating the degree of root development to compare tooth maturity. The supernumerary lateral incisors were in the normal direction at a rate of 90.9%, and in a supplemental shape at a rate of 84.1%. The supernumerary lateral incisor was smaller in size compared to the adjacent lateral incisor and opposite lateral incisor (p < .0001). There was no statistically significant difference in the development stage of root. Based on these results, the supernumerary lateral incisor is similar with the lateral incisor, but has a difference in the size of crown. It is necessary to distinguish the supernumerary lateral incisor from the lateral incisor precisely to reduce clinical complications.

Arteriovenous malformations (AVMs) are rare congenital anomalies characterized by direct communication between arteries and veins that bypass the capillary bed. AVMs may not manifest clinically until late infancy or childhood. In particular, facial AVMs can cause urgent life-threatening dental events. A 5-year-old girl without a medical history visited the hospital because of spontaneous gingival bleeding around the posterior gingival area of the lower left 2nd primary molar.
Angiography through the femoral approach under general anesthesia was performed for differential diagnosis and therapeutic option. The blood flow was effectively reduced after arterial embolization alone, and there was no evidence of recurrence at the 5-month follow-up.
The present study reports that embolization of the affected vessels can be a more effective and safe method than surgical resection for the treatment of AVM during the growth period.

The purpose of this study is to evaluate the effect of the spread of a new type of coronavirus infection (COVID-19) on the mental state in school-age children and parents focusing on the aspects of sleep disorders and depression. A questionnaire survey was conducted for 123 parents and 108 school-age children who visited Department of Pediatric Dentistry, Kyung Hee University Dental Hospital at Gangdong from April 2, 2020 through April 25, 2020, via the direct writing method. Participants were assessed with Pittsburgh Sleep Quality Index, Generalized Anxiety Disorder (GAD)-7, Center for Epidemiology Scale for Depression. Logistic regressions were used with a level of significance of 5%.
The prevalence of GAD, depression, and poor sleep in parents were 34.1%, 17.1% and 44.7%, respectively. The prevalence of GAD in children was 20.4%.
Logistic regression showed that stress from Emergency Alert Messages about COVID-19 was associated with GAD and depression in parents. In children, the degree of emotional change after COVID-19 was associated with GAD.
This study confirmed that there was a change in the psychological status of children and guardians due to the epidemic of coronavirus disease-2019, and it would be necessary to consider their psychological status during dental treatment.

This study aimed to evaluate the long-term outcomes of teeth treated with reattachment technique in children and adolescents. Twenty seven permanent anterior teeth from 21 patients treated with fragment reattachment were evaluated. Clinical photos and medical records were used to assess treatment outcomes. Effect of pulp treatment and the ratio of fragment on success rate were statistically analyzed. Detachment of fragment was observed in 17 teeth, and their duration of retention was 21.41 ± 23.39 months. Repeated trauma was found to be the most frequent causes of failure. Pulp treatment before reattachment did not affect the success rate (p > 0.05). The mean ratio of fragment was 0.482 ± 0.147, and the success rate was affected by the ratio of fragment (p = 0.018). The median retention time of the teeth was 72 months if the ratio was under 0.5, and 8 months for that of the others. A significant correlation was found between the ratio of fragment and retention time (p = 0.003). Reattachment can be a predictable treatment option for crown fracture in anterior teeth in children and adolescents when a fracture involves less than 50% of the clinical crown.

Since January 2019, insurance coverage for caries treatment of permanent teeth using composite resin in children aged 12 and under has started in South Korea. The purpose of this study was to compare the pattern of permanent molar composite resin restoration aged 12 and under before and after the insurance coverage from January 2009 to March 2020 in the Department of Pediatric Dentistry at Kyung Hee University Dental Hospital at Gangdong.
Since the insurance coverage was started in 2019, the frequency of permanent molar composite resin restoration aged 12 and under has increased more than twice. There was a significant change in frequency of resin restoration by shape of cavity comparing before and after the insurance coverage, whereas there was no significant difference in changes by patient age, gender and position of tooth.
As accessibility to the permanent tooth composite resin restoration is increased by the insurance coverage, which shows a fair survival rate, it is expected that it could be able to secure oral health in the early permanent dentition aged 12 and under.

The 61st Korean Academy of Pediatric Dentistry congress was hosted online for the first time in 2020 due to coronavirus disease-19. The congress was operated using the ZOOM platform. The aim of this paper is to analyze and evaluate the overall satisfaction and feedbacks from congress participants via anonymous Google Forms online survey. A test meeting was previously organized before the actual congress to facilitate the smooth process and the participants overall showed high satisfaction. Members who participated in test meeting compared to those who did not, found it significantly helpful, which contributed overall higher satisfaction with the online congress. Abstracts were accepted from the current pediatric dentistry residents and the oral presentations were also held online for the first time. The presenters and the judges were overall very satisfied. In an unguaranteed situation of termination of coronavirus disease-19, the decision to conduct an online congress was a favorable option.

The purpose of this study was to evaluate the skeletal and dentoalveolar effects and optimal timing for treatment of class II malocclusion with functional appliances in children and adolescents. A group of 30 patients with class II malocclusion were divided into 3 groups according to their use of functional appliance: Twin block, Activator, Fränkel appliance. The group was also divided into 2 groups according to the cervical vertebrae maturation method. Lateral cephalometric radiographs were analyzed pretreatment (T0) and osttreatment(T1). Among the functional appliances, treatment with Twin block and Activator showed significant increase in the length of the mandible (Co-Gn) and the lower anterior facial height (ANS to Me), whereas the overjet and overbite were significantly reduced. Treatment with Fränkel appliance showed significant improvement in the relationship of maxilla and mandible. In addition, if the functional appliance was used during the period of pubertal growth peak, there was a significant increase in mandibular length, improvement in the relationship of maxilla and mandible, labial inclination of lower incisors and decrease in overjet compared to the treatment before pubertal growth peak. Therefore, this studyindicates that using functional appliances for patients with class II malocclusion is effective and the optimal timing for using functional appliances is during pubertal growth peak.

The purpose of this study was to evaluate the accuracy and precision of the three-dimensional (3D) imaging system of children’s facial soft tissue by comparing linear measurements. The subjects of the study were 15 children between the ages of 7 and 12. Twenty-three landmarks were pointed on the face of each subject and 16 linear measurements were directly obtained 2 times using an electronic caliper. Two sets of 3D facial images were made by the 3D scanner. The same 16 measurements were obtained on each 3D image. In the accuracy test, the total average difference was 0.9 mm. The precision of 3D photogrammetry was almost equivalent to that of direct measurement. Thus, 3D photogrammetry by the 3D scanner in children had sufficient accuracy and precision to be used in clinical setting. However, the 3D imaging system requires the subject’s compliance for exact images. If the clinicians provide specific instructions to children while obtaining 3D images, the 3D device is useful for investigating children’s facial growth and development. Also the device can be a valuable tool for evaluating the results of orthodontic and orthopedic treatments.

The first dental visit is recommended at the time of the eruption of the first tooth and no later than 12 months of age. However, even before the age of 1, children can visit the dental hospital for various reasons. The purpose of this study was to analyze the reasons for the dental visit of infant. From January 2006 to December 2015, medical records of infants who visited the Department of Pediatric Dentistry of Kyung Hee University were analyzed. The total number of patients was 419 (238 males and 181 females). The reasons for the dental visits were trauma (47.5%), nataleonatal tooth (19.8%), dental caries (8.1%), teething problem (4.3%), abnormal frenum (3.6%), soft tissue swelling (3.6%), Bohn’s nodule (3.3%), cleft lip and palate (2.9%), gingival neoplasm (1.9%), tongue ulceration (1.7%), oral examination (1.4%), enamel hypoplasia (1.2%) and abnormal temporomandibular joint sound (0.7%). According to this study, there were various oral diseases that could occur in infants. Since infants are usually cared by caregivers, pediatricians, and obstetricians, education of oral diseases of infants is needed to manage the oral symptoms properly.