1.Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar
Jung Jin PARK ; Yoonjeong NOH ; Yoon Jeong CHOI ; Jae Hyun PARK ; Ji Hyun LEE ; Chooryung Judi CHUNG ; Kyung-Ho KIM
The Korean Journal of Orthodontics 2025;55(2):154-163
Objective:
Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.
Methods:
This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index.L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.
Results:
At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∠6-MnP and ∠8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.
Conclusions
Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.
2.Paeoniflorin Protects Retinal Pigment Epithelial Cells from High Glucose-Induced Oxidative Damage by Activating Nrf2-Mediated HO-1 Signaling
Cheol PARK ; Hee-Jae CHA ; Su Hyun HONG ; Jeong Sook NOH ; Sang Hoon HONG ; Gi Young KIM ; Jung-Hyun SHIM ; Jin Won HYUN ; Yung Hyun CHOI
Biomolecules & Therapeutics 2025;33(3):518-528
Oxidative stress due to hyperglycemia damages the functions of retinal pigment epithelial (RPE) cells and is a major risk factor for diabetic retinopathy (DR). Paeoniflorin is a monoterpenoid glycoside found in the roots of Paeonia lactiflora Pall and has been reported to have a variety of health benefits. However, the mechanisms underlying its therapeutic effects on high glucose (HG)-induced oxidative damage in RPE cells are not fully understood. In this study, we investigated the protective effect of paeoniflorin against HG-induced oxidative damage in cultured human RPE ARPE-19 cells, an in vitro model of hyperglycemia. Pretreatment with paeoniflorin markedly reduced HG-induced cytotoxicity and DNA damage. Paeoniflorin inhibited HG-induced apoptosis by suppressing activation of the caspase cascade, and this suppression was associated with the blockade of cytochrome c release to cytoplasm by maintaining mitochondrial membrane stability. In addition, paeoniflorin suppressed the HG-induced production of reactive oxygen species (ROS), increased the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2), a key redox regulator, and the expression of its downstream factor heme oxygenase-1 (HO-1). On the other hand, zinc protoporphyrin (ZnPP), an inhibitor of HO-1, abolished the protective effect of paeoniflorin against ROS production in HG-treated cells. Furthermore, ZnPP reversed the protective effects of paeoniflorin against HG-induced cellular damage and induced mitochondrial damage, DNA injury, and apoptosis in paeoniflorin-treated cells. These results suggest that paeoniflorin protects RPE cells from HG-mediated oxidative stress-induced cytotoxicity by activating Nrf2/HO-1 signaling and highlight the potential therapeutic use of paeoniflorin to improve the symptoms of DR.
3.Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar
Jung Jin PARK ; Yoonjeong NOH ; Yoon Jeong CHOI ; Jae Hyun PARK ; Ji Hyun LEE ; Chooryung Judi CHUNG ; Kyung-Ho KIM
The Korean Journal of Orthodontics 2025;55(2):154-163
Objective:
Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.
Methods:
This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index.L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.
Results:
At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∠6-MnP and ∠8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.
Conclusions
Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.
4.Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar
Jung Jin PARK ; Yoonjeong NOH ; Yoon Jeong CHOI ; Jae Hyun PARK ; Ji Hyun LEE ; Chooryung Judi CHUNG ; Kyung-Ho KIM
The Korean Journal of Orthodontics 2025;55(2):154-163
Objective:
Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.
Methods:
This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index.L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.
Results:
At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∠6-MnP and ∠8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.
Conclusions
Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.
5.Paeoniflorin Protects Retinal Pigment Epithelial Cells from High Glucose-Induced Oxidative Damage by Activating Nrf2-Mediated HO-1 Signaling
Cheol PARK ; Hee-Jae CHA ; Su Hyun HONG ; Jeong Sook NOH ; Sang Hoon HONG ; Gi Young KIM ; Jung-Hyun SHIM ; Jin Won HYUN ; Yung Hyun CHOI
Biomolecules & Therapeutics 2025;33(3):518-528
Oxidative stress due to hyperglycemia damages the functions of retinal pigment epithelial (RPE) cells and is a major risk factor for diabetic retinopathy (DR). Paeoniflorin is a monoterpenoid glycoside found in the roots of Paeonia lactiflora Pall and has been reported to have a variety of health benefits. However, the mechanisms underlying its therapeutic effects on high glucose (HG)-induced oxidative damage in RPE cells are not fully understood. In this study, we investigated the protective effect of paeoniflorin against HG-induced oxidative damage in cultured human RPE ARPE-19 cells, an in vitro model of hyperglycemia. Pretreatment with paeoniflorin markedly reduced HG-induced cytotoxicity and DNA damage. Paeoniflorin inhibited HG-induced apoptosis by suppressing activation of the caspase cascade, and this suppression was associated with the blockade of cytochrome c release to cytoplasm by maintaining mitochondrial membrane stability. In addition, paeoniflorin suppressed the HG-induced production of reactive oxygen species (ROS), increased the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2), a key redox regulator, and the expression of its downstream factor heme oxygenase-1 (HO-1). On the other hand, zinc protoporphyrin (ZnPP), an inhibitor of HO-1, abolished the protective effect of paeoniflorin against ROS production in HG-treated cells. Furthermore, ZnPP reversed the protective effects of paeoniflorin against HG-induced cellular damage and induced mitochondrial damage, DNA injury, and apoptosis in paeoniflorin-treated cells. These results suggest that paeoniflorin protects RPE cells from HG-mediated oxidative stress-induced cytotoxicity by activating Nrf2/HO-1 signaling and highlight the potential therapeutic use of paeoniflorin to improve the symptoms of DR.
6.Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar
Jung Jin PARK ; Yoonjeong NOH ; Yoon Jeong CHOI ; Jae Hyun PARK ; Ji Hyun LEE ; Chooryung Judi CHUNG ; Kyung-Ho KIM
The Korean Journal of Orthodontics 2025;55(2):154-163
Objective:
Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.
Methods:
This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index.L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.
Results:
At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∠6-MnP and ∠8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.
Conclusions
Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.
7.Paeoniflorin Protects Retinal Pigment Epithelial Cells from High Glucose-Induced Oxidative Damage by Activating Nrf2-Mediated HO-1 Signaling
Cheol PARK ; Hee-Jae CHA ; Su Hyun HONG ; Jeong Sook NOH ; Sang Hoon HONG ; Gi Young KIM ; Jung-Hyun SHIM ; Jin Won HYUN ; Yung Hyun CHOI
Biomolecules & Therapeutics 2025;33(3):518-528
Oxidative stress due to hyperglycemia damages the functions of retinal pigment epithelial (RPE) cells and is a major risk factor for diabetic retinopathy (DR). Paeoniflorin is a monoterpenoid glycoside found in the roots of Paeonia lactiflora Pall and has been reported to have a variety of health benefits. However, the mechanisms underlying its therapeutic effects on high glucose (HG)-induced oxidative damage in RPE cells are not fully understood. In this study, we investigated the protective effect of paeoniflorin against HG-induced oxidative damage in cultured human RPE ARPE-19 cells, an in vitro model of hyperglycemia. Pretreatment with paeoniflorin markedly reduced HG-induced cytotoxicity and DNA damage. Paeoniflorin inhibited HG-induced apoptosis by suppressing activation of the caspase cascade, and this suppression was associated with the blockade of cytochrome c release to cytoplasm by maintaining mitochondrial membrane stability. In addition, paeoniflorin suppressed the HG-induced production of reactive oxygen species (ROS), increased the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2), a key redox regulator, and the expression of its downstream factor heme oxygenase-1 (HO-1). On the other hand, zinc protoporphyrin (ZnPP), an inhibitor of HO-1, abolished the protective effect of paeoniflorin against ROS production in HG-treated cells. Furthermore, ZnPP reversed the protective effects of paeoniflorin against HG-induced cellular damage and induced mitochondrial damage, DNA injury, and apoptosis in paeoniflorin-treated cells. These results suggest that paeoniflorin protects RPE cells from HG-mediated oxidative stress-induced cytotoxicity by activating Nrf2/HO-1 signaling and highlight the potential therapeutic use of paeoniflorin to improve the symptoms of DR.
8.Key factors for successful eruption of the mandibular third molar after extraction of the mandibular second molar
Jung Jin PARK ; Yoonjeong NOH ; Yoon Jeong CHOI ; Jae Hyun PARK ; Ji Hyun LEE ; Chooryung Judi CHUNG ; Kyung-Ho KIM
The Korean Journal of Orthodontics 2025;55(2):154-163
Objective:
Extraction of the mandibular second molar (L7) and substitution by the mandibular third molar (L8) is an effective treatment option. This study aimed to evaluate spontaneously erupted L8 occlusion after L7 extraction, and identify the influencing factors.
Methods:
This study assessed 46 L8 from 28 patients using dental study models, panoramic radiographs, and lateral cephalograms obtained during L7 extraction (T1) and completion of L8 eruption (T2). At T2, samples were categorized as acceptable (A-group) or unacceptable (U-group) based on the American Board of Orthodontics index.L8 angulation and position, retromolar space, distance between the Xi point and mandibular first molar (L6), and Nolla stage were compared between the groups to identify the predictive factors for successful eruption.
Results:
At T2, 58.7% of L8 exhibited acceptable occlusion. Age at T1 was significantly higher in the U-group than that in the A-group. Angles ∠6-MnP and ∠8-MnP differed significantly between the groups at T2. Xi-L6 distance was considerably longer in the A-group than that in the U-group at T1 and T2. Younger age at extraction and Xi-L6 distance at T1 affected the acceptable occlusion.
Conclusions
Younger age at L7 extraction and adequate eruption space (Xi-L6 distance) appear to be the key factors for achieving acceptable L8 occlusion.
9.Social and Behavioral Factors Related to Contraception in Korean Adolescents with Sexual Experience: Based on the 2018 and 2021 Korea Youth Risk Behavior Web-Based Survey
Sohyun PARK ; Hong Ji SONG ; Junhee HAN ; Young-Gyun SEO ; Hye-Mi NOH ; Kyung Hee PARK ; Hye-Ji AN ; Yu-Jin PAEK
Korean Journal of Family Practice 2024;14(1):28-39
Background:
Adolescent unintended pregnancies can have detrimental effects on maternal and fetal health, impacting the social lives of young parents. Globally, there is an emphasis on preventing unintended pregnancies in adolescents through comprehensive contraceptive education. This study examined contraception practices and determinants among sexually active Korean adolescents.
Methods:
This study analyzed raw data from the 2018 and 2021 Korea Youth Risk Behavior Survey conducted by the Korea Disease Control and Prevention Agency. The cohort consisted of 6,042 adolescents who reported sexual experience, categorized into those always practicing contraception and those not. We scrutinized factors related to sexual behavior, such as contraception and sex education, as well as other social and behavioral factors.
Results:
Among sexually active adolescents, 47.9% of males and 48.1% of females consistently used contraception. The most prevalent contraceptive method was condoms (male 58.1%; female 59.6%). However, a significant portion of adolescents were not using contraception (male 29.4%; female 21.7%). Females who did not consistently use contraception exhibited higher pregnancy rates (2.4% vs. 11.3%). Consistent contraceptive users tended to live with their families and reported less sexual experience after drinking alcohol. Despite a decline in sexual education in schools from 2018 to 2021, the proportion of adolescents consistently using contraception increased.
Conclusion
To prevent unintended pregnancies among sexually active adolescents, consistent use of appropriate contraceptive methods is crucial.Comprehensive education on contraception should be extended beyond schools to include homes and primary healthcare settings. Policymakers and healthcare providers should consider these consequences when devising strategies to reduce unintended pregnancies among adolescents.
10.Full mouth rehabilitation of skeletal class II patient with regaining occlusal vertical dimension: a case report
Junghyun PARK ; Seoung-Jin HONG ; Janghyun PAEK ; Kwantae NOH ; Ahran PAE ; Kung-Rock KWON ; Hyeong-Seob KIM
The Journal of Korean Academy of Prosthodontics 2024;62(4):304-316
Class II malocclusions present with a different occlusal pattern to patients with Class I malocclusions, characterized by a large overjet and overbite in the anterior region, resulting in habitual mandibular protrusion during speech or mastication. When rehabilitating Class II patients, it is important to consider lateral and anterior guidance, to ensure balanced posterior guidance during protrusive movements before anterior contact, and to establish freedom in the intercuspal position. In this case, digital tools were used for the full-mouth rehabilitation of a skeletal class II patient. A virtual patient was created using facial scan data, digital facebow transfer and jaw motion tracking. Provisional restorations were fabricated based on the virtual patient. After identifying occlusal interference during anterior movement with the first provisional, the virtual patient was updated and the occlusal design was refined. For the final restorations, the virtual patient was updated again to reflect the functionally and esthetically satisfactory provisional restorations and their adapted occlusion. This digital approach facilitated accurate replication of the dynamic occlusal relationships, resulting in functionally and esthetically successful outcomes.

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