Hong-Keun Hyun | Seoul National University (original) (raw)

Papers by Hong-Keun Hyun

The Korean Academy Of Pediatric Dentistry, Nov 1, 2020

korea dental association, Oct 1, 2015

The journal of the Korean dental association, 2015

Objectives: The aim of this study was to assess the morphologic characteristics of two types of s... more Objectives: The aim of this study was to assess the morphologic characteristics of two types of stainless steel crowns (SSCs) for the first primary molar using a 3D scanner. Study design: Two types of SSCs, KIDS CROWN (KC) and 3M ESPE ND-96 (ND), for the first primary molars were scanned using a 3D scanner. The mesiodistal and buccolingual diameters at the height of the contour and the cervical margin, occlusocervical diameters on the mesial, distal, buccal, and lingual aspects were measured, and the crown shape ratio, the smooth surface crown height ratio, and the cervical convergence were calculated. Results: In the crown shape ratio of the mandibular SSC, KC was larger buccolingually compared with ND. In the smooth surface crown height ratio, ND was larger than KC in all of the maxilla and mesial, distal, and lingual aspects of the mandible. ND was more convergent to the cervical mesiodistally and buccolingually compared with KC. Conclusion: In the superimposed images of the maxi...

Dental Materials Journal, 2021

This study aimed to determine functionality and mechanical properties of dental splints. Five spl... more This study aimed to determine functionality and mechanical properties of dental splints. Five splints were tested: a control splint Filtek Z350XT (ZF), two splints with G-Fix (GF) and Light Fix (LF), and two wire-composite splints with ZF (ZW) and Ortho Connect Flow (CW). Periotest values, elastic modulus, flexural, compressive, and diametral tensile strength were measured. ZW and CW showed no significant differences in flexibility in labial or occlusal pressure of upper central incisors. LF, GF, and ZF did not differ in labial or palatal pressure. ZW and CW had higher flexibility than LF, GF, and ZF. LF had the lowest flexural and compressive strength but the highest diametral tensile strength. This study showed that ZW and CW might be options for flexible splints, whereas LF and GF would be options for rigid splints. Additionally, CW and LF/GF might be simpler alternatives to ZW and ZF, respectively.

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 2019

Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closu... more Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, supernumerary teeth, and delayed tooth eruption. Defects in the Runt-related transcription factor 2 (RUNX2), a master regulator of bone formation, have been identified in CCD patients. The aim of this study was to identify the molecular genetic causes in a CCD family with delayed tooth eruption. The 23-year-old female proband and her mother underwent clinical and radiographic examinations, and all coding exons of the RUNX2 were sequenced. Mutational analysis revealed a single nucleotide deletion mutation (NM_001024630.4 : c.357delC) in exon 3 in the proband and her mother. The single C deletion would result in a frameshift in translation and introduce a premature stop codon [p.(Asn120Thrfs*24)]. This would result in the impaired function of RUNX2 protein, which may be the cause of delayed eruption of permanent teeth in the family.

Journal of the Korean Dental Society of Anesthesiology, 2012

Background: This study evaluates the existing cardiopulmonary resuscitation (CPR) knowledge and s... more Background: This study evaluates the existing cardiopulmonary resuscitation (CPR) knowledge and skills of 1 st year dental students and also compares their CPR performance skill with those of 4 th year students. Methods: Incoming 1 st year and 4 th year dental students were surveyed about the level of their CPR knowledge before conventional CPR instruction. After we trained them for CPR performance, we tested CPR performance skill to randomly selected 10 1st year and 4 th year dental students and compared their CPR performance. Results: Overall CPR knowledge was low for both 1 st and 4 th year dental students. Especially, only 1 among 89 fourth year dental students answered the right sequence of CPR revised in 2010. Overall CPR performance was relatively low for both 1 st and 4 th year dental students. Irrespective of previous experiences of CPR education, their CPR performance was not statistically different. Conclusions: Retraining of CPR is a necessity. Information about the existing CPR knowledge for dental students will aid in establishing the goal of future CPR training and improve the current deficiency.

Dental materials : official publication of the Academy of Dental Materials, Sep 6, 2016

Bioactive glass (BAG) has been suggested as a possible additive for dental restorative materials ... more Bioactive glass (BAG) has been suggested as a possible additive for dental restorative materials because of its antimicrobial effect and potential for promoting apatite formation in body fluids. The purpose of this study was to investigate the effects of bacterial biofilm on the change of colorimetric value and translucency of novel BAG-containing composites having different initial surface roughness. Composites with 72wt% total filler load were prepared by replacing 15% of the silanized Sr glass with BAG (65 mol % Si; 4% P; 31% Ca), BAG-F (61% Si; 31% Ca; 4% P; 3% F; 1% B), or silanized silica. Light-cured discs of 2-mm thickness (n=10/group) were divided into 4 different surface roughness subgroups produced by wet polishing with 600 and then up to 1200, 2400, or 4000 grit SiC. CIE L*a*b* were measured and the color difference and translucency parameter (TP) were calculated before and after incubating in media with or without a Streptococcus mutans (UA 159) biofilm for 2 wks (no ag...

Children, 2022

Amelogenesis imperfecta (AI) is a heterogeneous group of rare genetic disorders affecting ameloge... more Amelogenesis imperfecta (AI) is a heterogeneous group of rare genetic disorders affecting amelogenesis during dental development. Therefore, the molecular genetic etiology of AI can provide information about the nature and progress of the disease. To confirm the genetic etiology of AI in a Korean family with an autosomal dominant inheritance, pedigree and mutational analyses were performed. DNA was isolated from the participating family members and whole-exome sequencing was performed with the DNA sample of the father of the proband. The identified mutation was confirmed by Sanger sequencing. The mutational analysis revealed a novel nonsense mutation in the FAM83H gene (NM_198488.5: c.1363C > T, p.(Gln455*)), confirming autosomal dominant hypocalcified AI. Full-mouth restorative treatments of the affected children were performed after the completion of the deciduous dentition. Early diagnosis of AI can be useful for understanding the nature of the disease and for managing the con...

Journal of Clinical Pediatric Dentistry, 2021

Objective: To compare the shear bond strength (SBS) after thermocycling of four universal adhesiv... more Objective: To compare the shear bond strength (SBS) after thermocycling of four universal adhesives applied in self-etch mode on dentin and etch-and-rinse mode on enamel. Study design: Flat 144 buccal or lingual dentin and enamel surfaces from 72 non-carious primary molars were prepared. Samples were segregated into 12 groups (n=12): Adper Single Bond 2 etch-and-rinse (SB_T) and Clearfil SE Bond self-etch (SE_S) applied to enamel and dentin served as controls. Scotch Bond Universal Adhesive (SBU), Clearfil S3 Bond Universal Adhesive (SEU), Tetric N-Bond Universal Adhesive (TEN), and All Bond Universal (BIS) were applied in etch-and-rinse mode to enamel and in self-etch mode to dentin. They were thermocycled for 5000 cycles. SBS testing and the evaluation of fracture mode were performed. Results: SB_T showed statistically higher SBS than other adhesive groups using etch-and-rinse mode on enamel. SE_S and BIS had statistically higher SBS than other adhesive groups using self-etch mode...

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 2018

Chronic infantile neurological cutaneous articular (CINCA) syndrome periodically causes fever alo... more Chronic infantile neurological cutaneous articular (CINCA) syndrome periodically causes fever along with inflammation in multiple organs. Patients with this condition are vulnerable to dental problems due to systemic inflammation. For uncooperative patients, general anesthesia has been widely used to control negative behavior. However, caution should be exercised when administering general anesthesia in these patients because this syndrome is pro-inflammatory. The present case report describes the clinical considerations of the dental treatment of an uncooperative child with CINCA syndrome who was treated under general anesthesia.

The importance of telemedicine using home healthcare system comes to the fore due to the COVID-19... more The importance of telemedicine using home healthcare system comes to the fore due to the COVID-19. Smartphone-based system can be a proper home healthcare tool for the diagnosis of early stages of diseases due to its portability, easy to use, and cost-effectiveness. Dental caries (DC) is one of the most common and serious diseases in dentistry. In the early stage of DC, white spot lesions (WSLs) can be observed. To detect WSLs, we demonstrate a smartphone-based multimode imaging system (SMIS) for the quantitative diagnosis of early DC. SMIS can offer RGB color, polarization, fluorescence, and multispectral imaging.

The Journal of Korea Assosiation for Disability and Oral Health, 2011

Angelman syndrome(AS) is a rare genetic neurological disorder. The main clinical characteristics ... more Angelman syndrome(AS) is a rare genetic neurological disorder. The main clinical characteristics of this syndrome are delayed neuropsychological development, intellectual disability, speech impairment, jerky movements especially hand-lapping, frequent laughter or smiling.AS is a classic example of genetic im- printing in that it is usually caused by deletion or inactivation of genes on the maternally inherited chro- mosome 15. The syndrome has oral manifestations such as diastemas, tongue thrusting, sucking/swallow- ing disorder, mandibular prognathism, frequent drooling, and excessive chewing behavior. The purpose of this paper is to describe the interesting aspects of the dental treatment of a childe with AS. Abstract 교신저자: 현홍근

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 2018

The purpose of this study was to analyze the ratio and rate of apical closure when inducing root ... more The purpose of this study was to analyze the ratio and rate of apical closure when inducing root growth of necrotic immature permanent teeth using alternative triple antibiotics. 24 permanent teeth in the treatment group and 27 premolars in the control group were retrospectively studied using periapical radiographs for more than 300 days after the first visit. The difference in the growth rate between the two groups was statistically compared using the Mann-Whitney test at a significance level of 0.05. There were no statistically significant differences between the two groups in the first month and during months 1-3, 3-6, and 6-12. After 12 months, the cumulative rate of decrease in the apical foramen width in the treatment group was 50.59% and that in the control group was 71.82%, which revealed a significant difference between the two groups. There were significant differences in the rates of decrease in the apical foramen width after 3, 6 months, and later period in the treatment group, respectively. The cumulative rate of increase in the root dentin area presented no statistically significant differences between the treatment group and control group during the entire period of examination.

The purpose of this study was to evaluate the effect of collagenase and esterase on the microtens... more The purpose of this study was to evaluate the effect of collagenase and esterase on the microtensile bond in dentin bonding. After resin composites were bonded to occlusal dentin. specimens were formed and stored in PBS, collagenase, or esterase solution After 4-week storage, was determined and, the results were as follows : 1. values of Single Bond 2 were lower than those of Clearfil SE Bond for all storage medium (p0.05). 3. In Clearfil SE Bond group, esterase solution lowered bond strength more than PBS(p>0.05). Collagenase solution lowered bond strength more than esterase solution(p>0.05) and PBS(p

The Korean Academy Of Pediatric Dentistry, Nov 1, 2020

korea dental association, Oct 1, 2015

The journal of the Korean dental association, 2015

Objectives: The aim of this study was to assess the morphologic characteristics of two types of s... more Objectives: The aim of this study was to assess the morphologic characteristics of two types of stainless steel crowns (SSCs) for the first primary molar using a 3D scanner. Study design: Two types of SSCs, KIDS CROWN (KC) and 3M ESPE ND-96 (ND), for the first primary molars were scanned using a 3D scanner. The mesiodistal and buccolingual diameters at the height of the contour and the cervical margin, occlusocervical diameters on the mesial, distal, buccal, and lingual aspects were measured, and the crown shape ratio, the smooth surface crown height ratio, and the cervical convergence were calculated. Results: In the crown shape ratio of the mandibular SSC, KC was larger buccolingually compared with ND. In the smooth surface crown height ratio, ND was larger than KC in all of the maxilla and mesial, distal, and lingual aspects of the mandible. ND was more convergent to the cervical mesiodistally and buccolingually compared with KC. Conclusion: In the superimposed images of the maxi...

Dental Materials Journal, 2021

This study aimed to determine functionality and mechanical properties of dental splints. Five spl... more This study aimed to determine functionality and mechanical properties of dental splints. Five splints were tested: a control splint Filtek Z350XT (ZF), two splints with G-Fix (GF) and Light Fix (LF), and two wire-composite splints with ZF (ZW) and Ortho Connect Flow (CW). Periotest values, elastic modulus, flexural, compressive, and diametral tensile strength were measured. ZW and CW showed no significant differences in flexibility in labial or occlusal pressure of upper central incisors. LF, GF, and ZF did not differ in labial or palatal pressure. ZW and CW had higher flexibility than LF, GF, and ZF. LF had the lowest flexural and compressive strength but the highest diametral tensile strength. This study showed that ZW and CW might be options for flexible splints, whereas LF and GF would be options for rigid splints. Additionally, CW and LF/GF might be simpler alternatives to ZW and ZF, respectively.

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 2019

Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closu... more Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, supernumerary teeth, and delayed tooth eruption. Defects in the Runt-related transcription factor 2 (RUNX2), a master regulator of bone formation, have been identified in CCD patients. The aim of this study was to identify the molecular genetic causes in a CCD family with delayed tooth eruption. The 23-year-old female proband and her mother underwent clinical and radiographic examinations, and all coding exons of the RUNX2 were sequenced. Mutational analysis revealed a single nucleotide deletion mutation (NM_001024630.4 : c.357delC) in exon 3 in the proband and her mother. The single C deletion would result in a frameshift in translation and introduce a premature stop codon [p.(Asn120Thrfs*24)]. This would result in the impaired function of RUNX2 protein, which may be the cause of delayed eruption of permanent teeth in the family.

Journal of the Korean Dental Society of Anesthesiology, 2012

Background: This study evaluates the existing cardiopulmonary resuscitation (CPR) knowledge and s... more Background: This study evaluates the existing cardiopulmonary resuscitation (CPR) knowledge and skills of 1 st year dental students and also compares their CPR performance skill with those of 4 th year students. Methods: Incoming 1 st year and 4 th year dental students were surveyed about the level of their CPR knowledge before conventional CPR instruction. After we trained them for CPR performance, we tested CPR performance skill to randomly selected 10 1st year and 4 th year dental students and compared their CPR performance. Results: Overall CPR knowledge was low for both 1 st and 4 th year dental students. Especially, only 1 among 89 fourth year dental students answered the right sequence of CPR revised in 2010. Overall CPR performance was relatively low for both 1 st and 4 th year dental students. Irrespective of previous experiences of CPR education, their CPR performance was not statistically different. Conclusions: Retraining of CPR is a necessity. Information about the existing CPR knowledge for dental students will aid in establishing the goal of future CPR training and improve the current deficiency.

Dental materials : official publication of the Academy of Dental Materials, Sep 6, 2016

Bioactive glass (BAG) has been suggested as a possible additive for dental restorative materials ... more Bioactive glass (BAG) has been suggested as a possible additive for dental restorative materials because of its antimicrobial effect and potential for promoting apatite formation in body fluids. The purpose of this study was to investigate the effects of bacterial biofilm on the change of colorimetric value and translucency of novel BAG-containing composites having different initial surface roughness. Composites with 72wt% total filler load were prepared by replacing 15% of the silanized Sr glass with BAG (65 mol % Si; 4% P; 31% Ca), BAG-F (61% Si; 31% Ca; 4% P; 3% F; 1% B), or silanized silica. Light-cured discs of 2-mm thickness (n=10/group) were divided into 4 different surface roughness subgroups produced by wet polishing with 600 and then up to 1200, 2400, or 4000 grit SiC. CIE L*a*b* were measured and the color difference and translucency parameter (TP) were calculated before and after incubating in media with or without a Streptococcus mutans (UA 159) biofilm for 2 wks (no ag...

Children, 2022

Amelogenesis imperfecta (AI) is a heterogeneous group of rare genetic disorders affecting ameloge... more Amelogenesis imperfecta (AI) is a heterogeneous group of rare genetic disorders affecting amelogenesis during dental development. Therefore, the molecular genetic etiology of AI can provide information about the nature and progress of the disease. To confirm the genetic etiology of AI in a Korean family with an autosomal dominant inheritance, pedigree and mutational analyses were performed. DNA was isolated from the participating family members and whole-exome sequencing was performed with the DNA sample of the father of the proband. The identified mutation was confirmed by Sanger sequencing. The mutational analysis revealed a novel nonsense mutation in the FAM83H gene (NM_198488.5: c.1363C > T, p.(Gln455*)), confirming autosomal dominant hypocalcified AI. Full-mouth restorative treatments of the affected children were performed after the completion of the deciduous dentition. Early diagnosis of AI can be useful for understanding the nature of the disease and for managing the con...

Journal of Clinical Pediatric Dentistry, 2021

Objective: To compare the shear bond strength (SBS) after thermocycling of four universal adhesiv... more Objective: To compare the shear bond strength (SBS) after thermocycling of four universal adhesives applied in self-etch mode on dentin and etch-and-rinse mode on enamel. Study design: Flat 144 buccal or lingual dentin and enamel surfaces from 72 non-carious primary molars were prepared. Samples were segregated into 12 groups (n=12): Adper Single Bond 2 etch-and-rinse (SB_T) and Clearfil SE Bond self-etch (SE_S) applied to enamel and dentin served as controls. Scotch Bond Universal Adhesive (SBU), Clearfil S3 Bond Universal Adhesive (SEU), Tetric N-Bond Universal Adhesive (TEN), and All Bond Universal (BIS) were applied in etch-and-rinse mode to enamel and in self-etch mode to dentin. They were thermocycled for 5000 cycles. SBS testing and the evaluation of fracture mode were performed. Results: SB_T showed statistically higher SBS than other adhesive groups using etch-and-rinse mode on enamel. SE_S and BIS had statistically higher SBS than other adhesive groups using self-etch mode...

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 2018

Chronic infantile neurological cutaneous articular (CINCA) syndrome periodically causes fever alo... more Chronic infantile neurological cutaneous articular (CINCA) syndrome periodically causes fever along with inflammation in multiple organs. Patients with this condition are vulnerable to dental problems due to systemic inflammation. For uncooperative patients, general anesthesia has been widely used to control negative behavior. However, caution should be exercised when administering general anesthesia in these patients because this syndrome is pro-inflammatory. The present case report describes the clinical considerations of the dental treatment of an uncooperative child with CINCA syndrome who was treated under general anesthesia.

The importance of telemedicine using home healthcare system comes to the fore due to the COVID-19... more The importance of telemedicine using home healthcare system comes to the fore due to the COVID-19. Smartphone-based system can be a proper home healthcare tool for the diagnosis of early stages of diseases due to its portability, easy to use, and cost-effectiveness. Dental caries (DC) is one of the most common and serious diseases in dentistry. In the early stage of DC, white spot lesions (WSLs) can be observed. To detect WSLs, we demonstrate a smartphone-based multimode imaging system (SMIS) for the quantitative diagnosis of early DC. SMIS can offer RGB color, polarization, fluorescence, and multispectral imaging.

The Journal of Korea Assosiation for Disability and Oral Health, 2011

Angelman syndrome(AS) is a rare genetic neurological disorder. The main clinical characteristics ... more Angelman syndrome(AS) is a rare genetic neurological disorder. The main clinical characteristics of this syndrome are delayed neuropsychological development, intellectual disability, speech impairment, jerky movements especially hand-lapping, frequent laughter or smiling.AS is a classic example of genetic im- printing in that it is usually caused by deletion or inactivation of genes on the maternally inherited chro- mosome 15. The syndrome has oral manifestations such as diastemas, tongue thrusting, sucking/swallow- ing disorder, mandibular prognathism, frequent drooling, and excessive chewing behavior. The purpose of this paper is to describe the interesting aspects of the dental treatment of a childe with AS. Abstract 교신저자: 현홍근

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY, 2018

The purpose of this study was to analyze the ratio and rate of apical closure when inducing root ... more The purpose of this study was to analyze the ratio and rate of apical closure when inducing root growth of necrotic immature permanent teeth using alternative triple antibiotics. 24 permanent teeth in the treatment group and 27 premolars in the control group were retrospectively studied using periapical radiographs for more than 300 days after the first visit. The difference in the growth rate between the two groups was statistically compared using the Mann-Whitney test at a significance level of 0.05. There were no statistically significant differences between the two groups in the first month and during months 1-3, 3-6, and 6-12. After 12 months, the cumulative rate of decrease in the apical foramen width in the treatment group was 50.59% and that in the control group was 71.82%, which revealed a significant difference between the two groups. There were significant differences in the rates of decrease in the apical foramen width after 3, 6 months, and later period in the treatment group, respectively. The cumulative rate of increase in the root dentin area presented no statistically significant differences between the treatment group and control group during the entire period of examination.

The purpose of this study was to evaluate the effect of collagenase and esterase on the microtens... more The purpose of this study was to evaluate the effect of collagenase and esterase on the microtensile bond in dentin bonding. After resin composites were bonded to occlusal dentin. specimens were formed and stored in PBS, collagenase, or esterase solution After 4-week storage, was determined and, the results were as follows : 1. values of Single Bond 2 were lower than those of Clearfil SE Bond for all storage medium (p0.05). 3. In Clearfil SE Bond group, esterase solution lowered bond strength more than PBS(p>0.05). Collagenase solution lowered bond strength more than esterase solution(p>0.05) and PBS(p