KJC Korea
Journal Central

The aim of this retrospective study was to investigate etiology, clinical features, and treatment modalities of the mandibular condyle fracture in children and young adolescents. This study was conducted based on medical records and radiographic examinations of 44 pediatric patients. Patients received treatment under diagnosis of mandibular condylar fracture. They were divided into 4 groups according to their age. The involvement of condyle in the mandible fracture occurred in higher percentage in younger age groups. Falling was the most common etiologic factor in all age group, especially in children with age under 7. Condyle head was the most frequent site of fracture in age group of 4 - 7 whereas fracture tends to occur in lower condylar areas in older groups. In 54.5% of the mandibular condyle fracture, symphysis fracture was accompanied. Teeth injury occurred in higher incidency when condyle fracture accompanied symphysis fracture. Conservative treatments were applied to 43 out of 44 patients.

The aim of this study is to investigate visual exploration of children and adolescents during dental treatment by examining time ratio of eye opening in various age groups. This study reviewed 5 - 15 year-old patients who visited the department of pediatric dentistry of Yonsei University Dental Hospital from March to October 2018. Restorative treatment or sealant application was done by one pediatric dentist. A trained observer used 2 stopwatches to measure total treatment time and time of open eye. Average ratios of eye opening were calculated and compared. 60 patients were investigated, with 15 patients in each age group. Average ratio of eye opening increased as age decreased (p < .001). The average of 13 - 15 year-olds was significantly shorter than that of children younger than 12 years (p < .005). This study indicated that children have higher rates of eye opening during dental treatment than adolescents.

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 purpose of this study is to evaluate the morphological characteristics of the roots and roots canals of primary molar teeth using Cone-Beam Computed Tomography (CBCT). A total of 68 CBCT images of children aged 4 - 5 years was used for this study. A total of 160 molar teeth were analyzed. Various parameters such as the number of roots and canals, length of root and root canal, and the angulation and shape of the roots were analyzed. All maxillary primary molars had 3 roots. The presence of 2 root canals in 1 root was only observed in the mesiobuccal root of maxillary primary second molars. Most mandibular primary molars had 2 roots, and most mesial roots had 2 root canals. Concerning the length of the roots, the palatal root of the maxillary primary molar was found to be longest whereas the distobuccal root was shortest. In mandibular primary molars, the mesial root was longer than the distal root. In maxillary primary molars, the palatal root had the greatest angulation whereas the distal root has the greatest in mandibular molars. The root and root canals of maxillary primary molars were more curved in shape whereas mandibular primary molars were straight.

The aim of this study was to assess the occlusal relationships of primary dentition of Korean preschool children in Hwaseong city. Total 444 children of age group between 2 and 5 years were selected. One pediatric dentist took intraoral photos of children. Evaluation and categorization of the primary molar relationships were done by single examiner. Statistical analysis was performed with Pearson chi-squared test. Total 389 samples, which is consisted of 185 boys, 204 girls were satisfied with inclusion criteria. Bilateral mesial step was seen in 61.7%. Bilateral flush terminal plane was seen in 15.4%. When the primary molar relations of the right and left sides were not the same, the combination of the mesial step and flush terminal plane was 14.7%. The present study provides insight into occlusal relationships in the primary dentition of 2 - 5 years old of Korean children in Hwaseong city. Pediatric dentists should understand occlusal relationships of primary dentition for establishment of appropriate treatment strategies and occlusal guidance.

The number of pediatric dental clinics has been increasing due to the development of dentistry and changes in public awareness of professional dental care for children. The purpose of this study was to investigate the present status of pediatric dental clinics in Korea in several respects, including regional distribution. There were 343 pediatric dental clinics (1.91%) among 17,917 dental clinics in Korea. 248 out of 343 private practitioners were board certified pediatric dentists. Of 248 board certified pediatric dentists, 25 displayed the specialty in their clinics’ name. Gyeonggi occupied largest share of the total pediatric dental clinics in Korea, followed by Seoul and Busan. Gangnam-gu occupied largest share of the total pediatric dental clinics in Seoul. Out of all pediatric dental clinics in Korea, 78.7% was run by only one dentist. 90.9% of pediatric dental clinics didn’t do night clinic on weekdays and 26.5% was open until after 15:00 on Saturday.

Midazolam is a short-acting benzodiazepine that is widely used in pediatric dental sedation. However, its clinical effectiveness as an intravenous sedative agent in children has not been widely documented. A retrospective study was conducted to evaluate the efficacy and safety of intravenous midazolam and nitrous oxide inhalation sedation in pediatric dental treatment. The subjects were 115 patients (118 cases) who received dental treatment under intravenous midazolam and nitrous oxide inhalation sedation. Demographic factors, general health status, sedation time, midazolam and nitrous oxide dosage, and success rate of sedation were evaluated from electronic medical records. Behavioral management was the main reason of choosing sedation. Mean duration of sedation was 56.7 minutes for surgical treatment, and 74.4 minutes for restorative treatment. The initial dosage of intravenous midazolam was 0.051 ± 0.019 mg/kg. In 34 cases (28.8%), additional midazolam of 0.036 ± 0.057 mg/kg was delivered during the treatment. The concentration of nitrous oxide was maintained between 40% and 50%. The success rate of sedation was 99% (n = 117). In 1 case, laryngospasm occurred and the patient was reversed with benzodiazepine antagonist, flumazenil. Intravenous midazolam sedation with nitrous oxide was shown to be clinically effective for the dental treatment in children, if administered by trained personnel and patients are carefully selected in accordance with guidelines.

This study intended to evaluate noise level of dental handpieces and the effects of noise cancelling devices. An ear model was designed to measure the level of the noise delivered to the inner ear during dental handpiece operation. The level of noise was measured in various conditions using the ear model and the portable noise meter. Noise level was measured again after applying of 4 different noise cancelling devices to the model ear. The noise level of dental handpieces was 82.5 - 84.4 dB. When 4 types of noise canceling devices were applied, the noise level reduced to 67.4 - 73.8 dB. All 4 devices had statistically significant effect in reducing the noise of the handpiece. Considering the intensity and exposure time, noise in dental clinics can cause hearing damage to dentists. For protection from the risk of occupational hearing damages, noise canceling devices can be recommended.

The present study is aimed to assess the effect of antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans biofilm through teeth whitening light emitting diode (LED). Planktonic and dynamic biofilm state cultures of S. mutans were used. Erythrosine 20 μM/L was used as the photosensitizer. Irradiation was performed by exposing cultures to clinic and homecare whitening LEDs for 15 minutes. The viability was measured through Colony Forming Unit counts and confocal laser scanning microscopy. aPDT using whitening LEDs and erythrosine significantly decreased the CFU count of S. mutans compared to that in the control group. Dynamic biofilm group showed more resistant features to aPDT compared with planktonic state. Clinic and homecare whitening LED device showed similar antimicrobial effect. The whitening LED, which could irradiate the entire oral arch, showed a significant photodynamic effect on cariogenic S. mutans biofilm. aPDT mediated by erythrosine and LEDs used for teeth whitening exhibited promising antimicrobial activity.

This study aimed to evaluate the relationship between parenting styles and childhood dental caries using a sample of 3 to 6 years old children in Korea. The subjects were 158 children aged 3 to 6 years old and their parents in Korea. The parenting styles were divided into three groups (authoritative, authoritarian, and permissive) using a translated version of the Parenting Styles and Dimensions Questionnaire (PSDQ). Among the 353 parents/child dyads, 158 questionnaires were returned. Authoritative parenting style was the majority (95.6%), followed by authoritarian (3.8%), and permissive (0.6%). There were no statistically significant differences between dental caries and parenting styles. The mean of dft index in authoritative group was lower than others. In the authoritative domain, the higher the authoritative tendency, the lower the dft index. Overall, authoritative parenting styles resulted in low rates of dental caries for the children. The stronger the authoritative tendency of the parents, the lower the experience of dental caries in the children. Therefore, parenting styles were likely to affect the oral health of a child, but it seemed necessary to supplement the evaluation tool to evaluate the parenting styles.

Adenomatoid odontogenic tumor (AOT) is a rare benign odontogenic jaw lesion. It usually occurs in the anterior maxilla and is mostly related to impacted canines in teenagers. A 3-year-old girl was referred from a local dental clinic due to delayed eruption of the right primary mandibular 2nd molar. There was no history of pain or swelling. Radiography revealed a large radiolucency lesion with radiopacities around the unerupted right primary mandibular 2nd molar. Surgical enucleation with extraction of the right primary mandibular 2nd molar and surgical biopsy were performed. Based on the clinical and radiological findings, this lesion was defined as an ameloblastic fibro-odontoma which often develops in the mandible of adolescents. However, this lesion was diagnosed as AOT from the results of the histological examination. This report aimed to present a rare case of AOT in the posterior mandibular area in a very young patient.

Lesch-Nyhan syndrome is a rare X-linked, recessively inherited disorder of purine metabolism, caused by complete absence of the enzyme hypoxanthine-guanine phosphoribosyl transferase. This syndrome is characterized by 3 major features: neurological dysfunction, hyperuricemia, and cognitive and behavioral disturbances (e.g., self-mutilation, which begins at 2 to 3 years of age). Uncontrollable self-mutilation begins with biting of the perioral tissues and extends into patterns such as finger biting and head hitting. This report describes the case of a 31-month-old boy who was diagnosed with Lesch-Nyhan syndrome with severe lip injuries caused by self-mutilative behaviors. The behaviors were blocked with a semi-fixed lip bumper for a short period. The device was applied to the patient on the day of the visit without the requirement for an oral impression. It was easy to manage oral hygiene and adjust the device because it was detachable by clinicians and guardians. Therefore, a semi-fixed lip bumper may be useful as an interim appliance to block selfmutilative behaviors in children with Lesch-Nyhan syndrome.