Trends in Saliva Research and Biomedical Clinical Applications / 대한소아치과학회지

Function of salivary gland and saliva composition can be an indicator of individual’s health status. Recently, saliva has been thought to have a high potential for usage in the biomedical field to diagnose, evaluate, and prevent systemic health due to the technological advances in analyzing and detecting small elements such as immunological and metabolic products, viruses, microorganisms, hormones in saliva. As a diagnostic specimen, saliva has some useful advantages compared to serum. Because of simple non-invasive method, saliva sampling is quite comfort for the patient, and it doesn’t require specialists to collect samples. The possibility of infection during the collection process is also low. For this reason, proteins, genetic materials, and various biomarkers in saliva are actively being utilized on studying stress, microbiomics, genetics, and epigenetics. For the research on collecting big data related to systemic health, the needs on biobank has been focused. Regeneration of salivary gland based on tissue engineering has been also on advancement. However, there are still many issues to be solved, such as the standardization of sample collection, storage, and usage. This review focuses on the recent trends in the field of saliva research and highlight the future perspectives in biomedical and other applications.

Utilization of an Artificial Intelligence Program Using the Greulich-Pyle Method to Evaluate Bone Age in the Skeletal Maturation Stage / 대한소아치과학회지

The purpose of this study was to measure bone age using an artificial intelligence program based on the Greulich-Pyle (GP) method to find out the bone age corresponding to each stage of cervical vertebral maturation (CVM) and the middle phalanx of the third finger (MP3). This study was conducted on 3,118 patients who visited pediatric dentistry at Kyung Hee University Dental Hospital and Pusan National University Dental Hospital from 2013 to 2021. The CVM stage was divided into 5 stages according to the classification by Baccetti, and the MP3 stage was divided into 5 stages according to the methods of Hägg and Taranger. Based on the GP method, bone age was evaluated using an artificial intelligence program. The pubertal growth spurt in the CVM stage was CVM II and III. The mean bone age in CVM II was 11.00 ± 1.81 years for males and 10.00 ± 1.49 years for females, and in CVM III, 13.00 ± 1.46 years for males and 12.00 ± 1.44 years for females (p < 0.0001). The pubertal growth spurt in the MP3 stage was MP3 - G stage. The bone age at the MP3 - G stage was 13.14 ± 1.07 years for males and 11.40 ± 1.09 years for females (p < 0.0001). Bone age evaluation using artificial intelligence is worth using in clinical practice, and it is expected that a faster and more accurate diagnosis will be possible.

The Prevalence and Characteristics of Pre-eruptive Intracoronal Radiolucencies in Children and Adolescents / 대한소아치과학회지

The purpose of this study was to investigate the prevalence and characteristics of pre-eruptive intracoronal radiolucencies (PEIR) from panoramic radiographs in Korean children and adolescents.This study examined panoramic radiographs of 3,000 patients aged between 5 and 14 years old who visited ten dental hospitals in Korea. The age and gender of the patients, the tooth type, the number of intracoronal radiolucent lesions, and the location and size of the lesions were recorded.The overall prevalence of patients with PEIR was 2.5%. The difference in the presence of PEIR between both genders was not significant. Within each tooth type, the mandibular first molar showed highest prevalence of PEIR (29.6%). The central part of the crown was the most frequently observed location of PEIR (56.8%). The size of the PEIR lesions was mostly limited to less than one-third of the thickness of coronal dentin.

Preoperative Factors of Immature First Permanent Molars Treated with Vital Pulp Therapy / 대한소아치과학회지

This study aimed to analyze the preoperative factors of immature first molars treated with vital pulp therapy and to find out their correlation in pediatric patients. From May 2014 to January 2020, 523 patients and 1,242 immature first molars were investigated. Factors including age, sex, tooth location, Molar-incisor hypomineralization (MIH), caries cavity location, and history of previous restoration were evaluated. As a result of the study, the vital pulp therapy group had 5.56 times more MIH, 3.39 times more mesial cavities, and 8.73 times more distal cavities. In order to avoid vital pulp therapy in immature first molar, early diagnosis and active management of MIH and preventive treatment of mesial and distal caries are necessary after its immediate eruption.

Cantilever-Type Traction Appliance for Mandibular First Permanent Molars with Eruption Disturbances / 대한소아치과학회지

Eruption disturbances of the mandibular first molars can cause multiple problems in occlusal development although they are extremely rare. Early diagnosis and treatment are very important to prevent complications associated with eruption disturbances. The present case report describes the treatment of two cases of eruption disturbances of the mandibular first permanent molar. A fixed appliance composed of a cantilever spring with mandibular second deciduous molar as an anchor tooth was used to tract the impacted mandibular first permanent molar. The success of both cases shows that this novel traction appliance can be used to induce the eruption of an impacted mandibular first permanent molar within a short time in patients with intact mandibular second deciduous molar as an anchor tooth.

Survival Rates of Class II Restoration in Primary Molar with Flowable Resin Composite / 대한소아치과학회지

The purpose of this retrospective study was to evaluate the survival rate by comparing Class II restoration using flowable resin composite with stainless steel crown in primary molars.Electronic medical records and radiographs of 1,504 primary molars with proximal caries of 590 patients from June 2015 to August 2019 were analyzed. With the collected data, survival analysis was performed using the Kaplan-Meier method.The 1-year survival rate of flowable resin composite in the primary molar was 98.5%, 3-year survival rate was 87.7%, and mean survival time was 39 months. There was no statistically significant difference between flowable resin composite and stainless steel crown (p = 0.896).Within the limits of this study, Class II restoration using flowable resin composite can be considered a promising option for the treatment of proximal caries in primary molars.

Semi-Fixed Lip Bumper in Lesch-Nyhan Syndrome: An Interim Treatment Modality / 대한소아치과학회지

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 self-mutilative behaviors in children with Lesch-Nyhan syndrome.

Microleakage Assessment of Resin Infiltration Combined Restoration in Artificial Decalcified-Cavitated Lesion / 대한소아치과학회지

This study was performed to evaluate the restoration combined with resin infiltration (RI) of early cavitated smooth surface caries lesion in terms of microleakage. Flowable resin and resin-modified glass ionomer cement (RMGIC) were compared. Sound 20 extracted 3rd molars were divided into 2 groups randomly. Artificial decalcified lesion was induced. Cavities were prepared on the mesial and distal surfaces, and randomly set as experimental and control group. RI was applied to the experimental group before cavity restoration. The control group was restored without RI. In group I and II, flowable resin and RMGIC was used for restoration respectively. After thermocycling and silver nitrate immersion, microleakage was assessed by μ-CT. Depth of microleakage was lower in experimental group than control group only in group II (p = 0.05). Microleakage depth was lower in group II than group I in both xperimental and control groups (p = 0.05). RI pretreatment before restoration of early cavitated caries lesions might reduce the microleakage and help long-term maintenance of restoration. In this study, RMGIC was less polymerization shrinkage. Restoration with RMGIC after RI pretreatment reduced the microleakage of the restoration compared to the flowable resin.

Utilization of Resin Infiltration for the Minimally Invasive Composite Restoration / 대한소아치과학회지

This study was aimed to assess the new trial for minimal cavity preparation in composite restoration combined with resin infiltration, focusing at application sequence.32 human primary molars with early carious lesions around small cavity were selected and randomly divided into two groups, according to the sequence of cavity preparation (P), composite filling (F) and resin infiltration (I) as IPF and PFI group. Each group was assessed about amount of tooth reduction, features of resin infiltration, and marginal leakage around restoration.Amount of tooth reduction evaluated using micro-CT was decreased compared with the original lesion size in both groups. Features of resin infiltration were verified under confocal laser scanning microscopy. In both groups, infiltrant resin was found on all around the composite and maintained in spite of extent of decalcification even after artificial caries induction. Marginal micro leakage assessed with silver nitrate immersion and micro-CT was found more frequently in PFI group.The technique combining resin infiltration and composite restoration might ensure better adhesion prognosis as applied by the sequence of resin infiltration, cavity preparation, and composite filling. This new trial was thought meaningful in minimizing the cavity size and contributing to minimal invasive dentistry.

Diagnostic Utilization of Laser Fluorescence for Resin Infiltration in Primary Teeth / 대한소아치과학회지

This study was performed to evaluate clinical use of laser fluorescence (LF) to identify early childhood caries lesions suitable for applying resin infiltration.20 exfoliated primary molars with proximal caries were selected and cut buccolingually cross the central pit for regarding the mesial and distal surfaces respectively. 27 specimens corresponding to ICDAS code 1 and 2 were selected and the LF values were measured. When infiltrant resin was applied, double staining for microscopy detection has done simultaneously. Tooth samples were sliced with 0.7 mm thick. The maximum lesion depth, maximum penetration depth, and average penetration rate were measured from the confocal scanning laser microscope image. Pearson correlation analysis was performed.The intraclass correlation coefficient of LF values shows excellent agreement. LF values had positive correlation with penetration rate, but not lesion depth and penetration depth. Significant correlation between LF readings and penetration rate was verified in deep enamel caries and dentin caries except shallow enamel caries.Infiltrant resin could penetrate with a higher rate and LF values could be increased in more active caries lesions. In assessing radiologically similar caries lesion, laser fluorescence might be useful for identifying caries activity.

Effect of Saliva Decontamination on Bond Strength of 1-step Self-etching Adhesives to Dentin of Primary Posterior Teeth / 대한소아치과학회지

The purpose of this study was to evaluate effect of saliva decontamination procedures on microtensile bond strength (MTBS) of 1-step self-etching adhesives to dentin of primary posterior teeth.63 sound primary-posterior teeth were randomly divided into 3 groups according to different kinds of 1-step self-etching adhesives: Scotchbond™ Universal Adhesive (SBU), All-Bond Universal® (ABU), and Tetric® N Bond Universal (TBU). Each group was randomly categorized into 7 subgroups: (I) application of adhesive without saliva contamination (control); (II – IV) contamination by saliva before photopolymerization; (V – VII) contamination by saliva after photopolymerization; (II, V) decontamination by drying; (III, VI) decontamination by washing and drying; (IV, VII) decontamination by washing, drying, and reapplication of adhesive. All samples were cut into the blocks. At least 15 blocks were tested for each subgroup.For SBU and ABU, the MTBS values of subgroups (I, IV, VII) were significantly higher than those of subgroups (II, III, V, VI). For TBU, the MTBS values of subgroups (I, IV) was significantly higher than those of subgroup (II, III, V, VI).The MTBS of 3 adhesives was reduced by saliva contamination. The adhesive strength on dentin of primary posterior teeth was restored by reapplication of the adhesives after washing and drying.

Effectiveness of Oral Health Education Program using Home-using Portable Device for Children / 대한소아치과학회지

This study was performed to determine the effectiveness of oral health education program with a home-using portable device according to the individual oral health status in children.58 children who were 6 – 12 years old were included in this study. All subjects were affiliated to moderate or high caries risk group based on caries risk test. They were divided into 2 groups: (I) home-using portable device group (II) control group. Both groups were evaluated with simple plaque score (SPS) using camera type quantitative light-induced fluorescence device and educated with identical oral health education methods. Subjects in group I were demanded to use a home-using portable device. After 1 month, both groups were re-evaluated.Cariview score that can reflect the acidogenic potential of plaque bacteria was statistically reduced in both groups (p < 0.001). There was a statistically significant difference between two groups in the change of Cariview score (p = 0.022). In group I, the decrease was larger than that in group II. There was no statistically significant difference in the change of SPS (p = 0.937).Oral health education improved oral hygiene status in children. However, this study confirmed that it was much more effective to improve oral health status in children with a home-using portable device in their daily oral hygiene care.

Effects of Maxillary Lateral Incisor Agenesis on Skeletodental Characteristics in Mixed Dentition / 대한소아치과학회지

This study aimed to evaluate skeletodental characteristics of patient with maxillary lateral incisor agenesis (MLIA) in mixed dentition.It involved the children in early mixed dentition who visited Pusan National University dental hospital for orthodontic purposed and had intact primary canines. 38 children with MLIA and 38 controls with the same chronological age satisfying the inclusion criteria were selected. The craniofacial structures and dental arch dimensions of the MLIA were evaluated using model & cephalometric analysis and compared to controls.The rate of unilateral MLIA was high in male and the rate of bilateral MLIA was high in female. In model analysis, the width / length ratio of maxillary anterior portion of the MLIA group were higher and arch perimeter of the maxilla of the MLIA group were smaller than those of the control group (p = 0.003, 0.04). Cephalometric analysis showed that there were no significant differences in terms of skeletal, dental analysis. In soft tissue profile, nasolabial angle was larger in MLIAs than in controls (p = 0.039).Considering these skeletodental characteristics of MLIA, early diagnosis and proper management is highly recommended to minimize the possibility of functional defect.

Effect of Developmental Disorders of Maxillary First Molars on Orofacial Morphology / 대한소아치과학회지

This study was aimed to evaluate orofacial morphologies on the cases of developmental disorders of maxillary first molars.Panoramic radiographs, lateral cephalographs, and clinical photos of 2983 children who attended the Pediatric Dental Clinic of Pusan National University Dental Hospital from 2006 to August 2017 were assessed retrospectively. 34 patients were selected whose maxillary first molars were missed or developmentally delayed unilaterally or bilaterally. Demirjian' s method was used for estimating dental age, then which was compared to chronologic age of children. Parameters expressing skeletal and dentoalveolar disharmony were checked and compared with control. Additionally, occlusion relationship was evaluated.Maxillary dental age was significantly delayed compared to chronologic age. Several parameters which show skeletal open-bite tendency and skeletal class III malocclusion with maxillary retrusion were statistically significant. Anterior crossbite and edge-bite were expected in most of these cases, but compensation by occlusion and soft tissue was also verified which might mask skeletal class III tendency.Congenital missed or developmentally delayed maxillary first molars might be related with declined growth of maxilla. If developmental disorders of maxillary first molars were verified during clinical examination, careful monitoring of orofacial growth was necessary during puberty and timed orthopedic and orthodontic intervention were considered.

Effects of Myofunctional Appliance in Children with Sleep-Disordered Breathing: Two Case Reports / 대한소아치과학회지

Sleep-disordered breathing (SDB) induces dysfunction of the orofacial muscles, leading to morphologic alteration of the face and dental malalignment. Early diagnosis and treatment of SDB is required in pediatric patients to ensure normal facial growth. Myofunctional therapy (MFT) is a modality for the treatment of SDB and prefabricated appliances can be used. Herein 2 cases of malocclusion with SDB, in which MFT with a prefabricated appliance was used for orthodontic treatment, have been described. SDB was diagnosed based on clinical symptoms taken by interview and home respiratory polygraphy. In both cases, SDB was improved using prefabricated appliance for MFT. However, resolution of crowding depended on the degree of crowding.

Shear Bond Strength of a 3-in-1 Flowable Composite Resin to Primary Teeth / 대한소아치과학회지

The purpose of this study was to compare the shear bond strengths of 3-in-1 flowable composite to the enamel and dentin of primary teeth to previous adhesive systems. 110 primary incisors were prepared and divided into two groups: Dentin group included 5 groups: 1) Scotch bond Multi-purpose plus(DSM), 2) Single-bond 2(DSB), 3) Clearfil SE bond(DSE), 4) All bond universal(DAB), 5) Constic(DC), and Enamel group included 6 groups: 1) Scotch bond Multipurpose plus(ESM), 2) Single bond 2(ESB), 3) Clearfil SE bond(ESE), 4) All bond universal(EAB), 5) Constic(EC), 6) Constic with additional etching(ECE). A cylinder of composite was bonded to the prepared surface, and the shear bond strength was measured. In the dentin groups, group DC had significantly lower shear bond strength than group DSE. No significant difference was found between group DC, group DSM, group DSB and group DAB. In the enamel groups, there was no significant difference between group EC, group ESE, and group EAB. This material showed lowest shear bond strength among all tested materials in both enamel and dentin groups, showing insignificant difference with some adhesive systems. Therefore, 3-in-1 flowable composite can be used for primary teeth restoration but further studies are needed.

Survey of Oral Health Education Effects in Twenties / 대한소아치과학회지

The purpose of this study was to improve efficacy of oral health education in children and adolescents based on the experience and perception of oral health education in young adults who graduated from high school within 10 years.Questionnaires were given to 412 people, and among them, 388 completed survey forms were selected. The questionnaire included categories which examined one's experience and perception of oral health education, oral health knowledge, dental history, and oral health behavior.The results showed that the respondents perceived elementary school as the most effective period of oral health education. Oral examination with direct explanation was the most preferred method of oral health education, but web search was the main source of oral health information. And knowledge of fluoride and sealant about caries preventive effect was still lacking. Considering these results, oral examination with direct explanation and web search would be useful to improve efficacy of oral health education in children and adolescents.

A Modified Pretreatment with Deproteinization for Resin Infiltration in Early Childhood Caries / 대한소아치과학회지

This study aimed to evaluate surface morphology and resin tag penetration of resin infiltration into primary anterior teeth after enamel deproteinization with sodium hypochlorite (NaOCl) prior to phosphoric acid (H₃PO₄) etching.Ninety primary anterior teeth with non-cavitated caries lesion were devided five groups according to enamel pretreatment as follows, group I-15% hydrochloric acid (HCl) 2min. ; group II-5.25% NaOCl 1min., 35% H₃PO₄ 1min. ; group III-5.25% NaOCl 2min., 35% H₃PO₄ 1min. ; group IV-5.25% NaOCl 1min., 35% H₃PO₄ 2min. ; group V-5.25% NaOCl 2min., 35% H3PO4 2min. Fifteen teeth were examined etched surface structure using field emission-scanning electron microscope. Seventy five teeth were infiltrated with resin, maximum penetration depth and percentage penetration were analysed using dual fluorescence confocal microscopy.As the application time of NaOCl increased, ratio of enamel type I, II were increased. Percentage penetration (PP) was higher in group V than group II, III (p < 0.05). PP of group IV, V did not show any differences.Non-cavitated caries of primary anterior teeth can be treated with resin infiltration. Enamel deproteinization with NaOCl prior to 35% H3PO4 etching could be an alternative of 15% HCl etching in resin infiltration.

Alternative Pretreatment Methods for Resin Infiltration in Primary Anterior Teeth / 대한소아치과학회지

Resin infiltration has been used as a treatment option for the management of early caries lesions recently. However, the etching procedure with hydrochloric acid might be somewhat stressful for the clinicians due to safety problem especially for young children, leading to less utility.This study aims at searching for some alternative surface pretreatment methods of resin infiltration for the early caries lesions in primary anterior teeth by comparing penetration depth of various methods.No significant difference was found in penetration ratio between etched surface with 15% hydrochloric acid and 35% phosphoric acid. However, the penetration ratio was significantly higher in groups pretreated either with dental pumice or abrasive metal strip (p < .05).By the result of this study, etching with phosphoric acid as an alternative of hydrochloric acid was thought clinically acceptable as a pretreatment method for resin infiltration in early caries lesions for primary anterior teeth.It was notable that surface conditioning with dental pumice or metal strip before etching was effective in increasing the penetration. This procedural modification might be much more correspondent with minimally invasive concept and hopefully contribute to increased safety and utility in pediatric dentistry.

A Morphometric Study of the Stainless Steel Permanent Molar Crown with Three-Dimensional Scanner / 대한치과재료학회지

The aim of this study was to compare the morphological characteristics of two types of stainless steel permanent molar crowns using three-dimensional scanners and the morphological changes of these crowns after crimping. Two types of stainless steel permanent molar crowns, PO-96 and PERMACROWN were scanned using three-dimensional scanner. Crown size, crown index (ratio of buccolingual diameter to mesiodistal diameter at height of contour), cervical convergency of crown were measured. Stainless steel crowns were crimped and re-scanned with three-dimensional scanner. Morphological changes of stainless steel permanent molar crowns were analyzed. As for the crown index, maxillary PERMACROWN was larger buccolingually and smaller mesiodistally than maxillary PO-96 and mandibular PERMACROWN was smaller buccolingually and larger mesiodistally than mandibular PO-96. Maxillary PO-96 was more convergent to cervical mesiodistally than maxillary PERMACROWN and mandibular PO-96 was more convergent to the cervical mesiodistally, buccolingually than mandibular PERMACROWN. Both types of stainless steel permanent molar crowns showed reduction of cervical circumference after crimping. Two products were morphologically different in crown size, shape and cervical convergence. Although both types of stainless steel permanent molar crowns are pre-contoured type, additional crimping is needed to achieve better marginal adaptation.