1.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
2.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
3.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
4.Study Protocol of Expanded Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro-EXP)
Jae Hoon MOON ; Eun Kyung LEE ; Wonjae CHA ; Young Jun CHAI ; Sun Wook CHO ; June Young CHOI ; Sung Yong CHOI ; A Jung CHU ; Eun-Jae CHUNG ; Yul HWANGBO ; Woo-Jin JEONG ; Yuh-Seog JUNG ; Kyungsik KIM ; Min Joo KIM ; Su-jin KIM ; Woochul KIM ; Yoo Hyung KIM ; Chang Yoon LEE ; Ji Ye LEE ; Kyu Eun LEE ; Young Ki LEE ; Hunjong LIM ; Do Joon PARK ; Sue K. PARK ; Chang Hwan RYU ; Junsun RYU ; Jungirl SEOK ; Young Shin SONG ; Ka Hee YI ; Hyeong Won YU ; Eleanor WHITE ; Katerina MASTROCOSTAS ; Roderick J. CLIFTON-BLIGH ; Anthony GLOVER ; Matti L. GILD ; Ji-hoon KIM ; Young Joo PARK
Endocrinology and Metabolism 2025;40(2):236-246
Background:
Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making.
Methods:
This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes.
Conclusion
This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.
5.Comparison of Temperatures of the Resin Cement in Polycrystalline Ceramic Brackets Irradiated Using a Diode Laser
Young-Tak SON ; KeunBaDa SON ; Kyung-Min KIM ; Jae-Mok LEE ; Jin-Wook KIM ; Wonjae YU ; Kyu-Bok LEE
Journal of Korean Dental Science 2021;14(2):69-78
Purpose:
The primary objective of this study was to evaluate the change in the temperature of the adhesive resin in polycrystalline ceramic brackets irradiated using a diode laser at different irradiation energy levels and times.
Materials and Methods:
For the measurement of the temperature of the adhesive resin, it was applied at the base of the ceramic bracket, a thermocouple was placed at the center of the base surface, the bracket was placed on prepared resin specimens for light curing, and a laser was irradiated to the center of the bracket slot at 5, 7, and 10 W. For the measurement of the temperatures of the enamel under the bracket and pulp cavity, extracted premolar was fixed to a prepared mold and the ceramic bracket was bonded to the buccal surface of the premolar. The Kruskal–Wallis H test and Friedman test were used for statistical analysis.Result: At 5 W, the temperature of the adhesive resin did not reach the resin softening temperature of 200°C within 30 seconds. At 7 W, it reached 200°C when the ceramic bracket was irradiated continuously for 28 seconds. At 10 W, it reached 200°C when the ceramic bracket was irradiated continuously for 15 seconds. During laser irradiation, the temperature of the enamel under the bracket increased by over 5°C within 15 seconds.
Conclusion
The use of diode laser irradiation for bracket debonding should be carefully considered because the pulp cavity temperature increases by over 5°C within the irradiation time for resin thermal softening.
6.A prospective randomized clinical study evaluating the efficacy and compliance of oral sulfate solution and 2-L ascorbic acid plus polyethylene glycol
Ki Hwan KWON ; Ji Ae LEE ; Yun Jeong LIM ; Beom Jae LEE ; Moon Kyung JOO ; Yu Ra SIM ; Wonjae CHOI ; Taehyun KIM ; Ji Yoon KIM ; Ei Rie CHO ; Yoon Tae JEEN ; Jong-Jae PARK
The Korean Journal of Internal Medicine 2020;35(4):873-880
Oral sulfate solution (OSS) is an emerging cleansing agent for bowel preparation. However, data comparing OSS to other conventional bowel preparations in Asian patients are limited. Therefore, the objective of this study was to compare the efficacy and tolerability of OSS to ascorbic acid plus polyethylene glycol (AA + PEG) in Asian patients. Methods: This was a prospective, randomized, parallel, investigator-blind study performed in two university hospitals in Korea. Bowel preparation efficacy was evaluated using both the Ottawa Bowel Preparation Scale (OBPS) and Boston Bowel Preparation Scale (BBPS). Results: Among 173 patients, 86 received OSS while 87 received AA + PEG for bowel preparation. Total OBPS score was 2.80 ± 2.48 in the OSS group and 4.49 ± 3.08 in the AA + PEG group, indicating significantly (p < 0.001) better efficacy with OSS. Total BBPS was higher in the OSS group (7.43 ± 1.49 vs. 6.51 ± 1.76, p < 0.001), indicating superior bowel preparation quality with OSS. Preparation-related adverse events were generally acceptable. Patients receiving OSS had more nausea (1.92 ± 0.94 vs. 1.54 ± 0.76, p = 0.004) and abdominal cramping (1.45 ± 0.78 vs. 1.17 ± 0.51, p = 0.006) than those receiving AA + PEG. However, overall satisfaction and taste were similar between the two groups. Conclusions: OSS had a non-inferior bowel cleansing efficacy than AA + PEG regardless of colon segment.
7.Comparison of inclination and vertical changes between single-wire and double-wire retraction techniques in lingual orthodontics
Bui Quang HUNG ; Mihee HONG ; Wonjae YU ; Hee Moon KYUNG
The Korean Journal of Orthodontics 2020;50(1):26-32
OBJECTIVE:
The Heat Induction Typodont System (HITS), used in some recent studies, has a distinct advantage over previous tooth movement simulation methods. This study aimed to compare inclination and vertical changes between the single-wire and double-wire techniques during en masse retraction with different lengths of lever arms in lingual orthodontics using an upgraded version of the HITS.
METHODS:
Duet lingual brackets, which have two main slots, were used in this study. Forty samples were divided into four groups according to the length of the lever arm (3-mm or 6-mm hook) and the retraction wire (single-wire or double-wire). Four millimeters of en masse retraction was performed using lingual appliances. Thereafter, 3-dimensional-scanned images of the typodont were analyzed to measure inclination and vertical changes of the anterior teeth.
RESULTS:
Incisor inclination presented more changes in the single-wire groups than in the double-wire groups. However, canine inclination did not differ between these groups. Regarding vertical changes, only the lateral incisors in the single-wire groups presented significantly larger values than did those in the double-wire groups. Combining the effect of hook lengths, among the four groups, the single-wire group with the 3-mm hook had the highest value, while the double-wire group with the 6-mm hook showed the least decrease in crown inclination and extrusion.
CONCLUSIONS
The double-wire technique with an extended lever arm provided advantages over the single-wire technique with the same lever arm length in preventing torque loss and extrusion of the anterior teeth during en masse retraction in lingual orthodontics.
8.Effect of surface anodization on stability of orthodontic microimplant.
Sanket KARMARKER ; Wonjae YU ; Hee Moon KYUNG
The Korean Journal of Orthodontics 2012;42(1):4-10
OBJECTIVE: To determine the effect of surface anodization on the interfacial strength between an orthodontic microimplant (MI) and the rabbit tibial bone, particularly in the initial phase after placement. METHODS: A total of 36 MIs were driven into the tibias of 3 mature rabbits by using the self-drilling method and then removed after 6 weeks. Half the MIs were as-machined (n = 18; machined group), while the remaining had anodized surfaces (n = 18; anodized group). The peak insertion torque (PIT) and the peak removal torque (PRT) values were measured for the 2 groups of MIs. These values were then used to calculate the interfacial shear strength between the MI and cortical bone. RESULTS: There were no statistical differences in terms of PIT between the 2 groups. However, mean PRT was significantly greater for the anodized implants (3.79 +/- 1.39 Ncm) than for the machined ones (2.05 +/- 1.07 Ncm) (p < 0.01). The interfacial strengths, converted from PRT, were calculated at 10.6 MPa and 5.74 MPa for the anodized and machined group implants, respectively. CONCLUSIONS: Anodization of orthodontic MIs may enhance their early-phase retention capability, thereby ensuring a more reliable source of absolute anchorage.
Rabbits
;
Retention (Psychology)
;
Shear Strength
;
Tibia
;
Torque
9.Cervical design effect of dental implant on stress distribution in crestal cortical bone studied by finite element analysis.
Kyung Tak KIM ; Kwang Heon JO ; Cheong Hee LEE ; Wonjae YU ; Kyu Bok LEE
The Journal of Korean Academy of Prosthodontics 2009;47(4):385-393
STATEMENT OF PROBLEM: High stress concentration on the crestal cortical bone has been regraded as a major etiologic factor jeopardizing long term stability of endosseous implants. PURPOSE: To investigate if the design characteristics of crestal module, i.e. internal type, external type, and submerged type, affect stress distribution on the crestal cortical bone. MATERIAL AND METHODS: A cylindrical shaped implant, 4.3 mm in diameter and 10 mm in length, with 3 different crestal modules, i.e. internal type, external type, and submerged type, were analysed. An axisymmetric scheme was used for finite elment formulation. A vertical load of 50 N and an oblique load of 50 N acting at 45degrees with the implant's long axis was applied. The peak crestal bone stress acting at the intersection of implant and crestal bone was compared. RESULTS: Under vertical load, the crestal bone stress was high in the order of internal, external, and submerged types. Under the oblique loading condition, it was in the order of internal, submerged, and external types. CONCLUSION: Crestal module design was found to affect the level of the crestal bone stresses although the actual amount was not significant.
Axis, Cervical Vertebra
;
Dental Implants
;
Finite Element Analysis
10.Finite element analysis of peri-implant bone stress influenced by cervical module configuration of endosseous implant.
Jae Min CHUNG ; Kwang Heon JO ; Cheong Hee LEE ; Wonjae YU ; Kyu Bok LEE
The Journal of Korean Academy of Prosthodontics 2009;47(4):394-405
STATEMENT OF PROBLEM: Crestal bone loss, a common problem associated with dental implant, has been attributed to excessive bone stresses. Design of implant's transgingival (TG) part may affect the crestal bone stresses. PURPOSE: To investigate if concavely designed geometry at a dental implant's TG part reduces peri-implant bone stresses. MATERIAL AND METHODS: A total of five differently configured TG parts were compared. Base model was the ITI one piece implant (Straumann, Waldenburg, Switzerland) characterized by straight TG part. Other 4 experimental models, i.e. Model-1 to Model-4, were designed to have concave TG part. Finite element analyses were carried out using an axisymmetric assumption. A vertical load of 50 N or an oblique load of 50 N acting at 30degrees with the implant's long axis was applied. For a systematic stress comparison, a total of 19 reference points were defined on nodal points around the implant. The peak crestal bone stress acting at the intersection of implant and crestal bone was estimated using regression analysis from the stress results obtained at 5 reference points defined along the mid plane of the crestal bone. RESULTS: Base Model with straight configuration at the transgingival part created highest stresses on the crestal bone. Stress level was reduced when concavity was imposed. The greater the concavity and the closer the concavity to the crestal bone level, the less the crestal stresses. CONCLUSION: The transgingival part of dental implant affect the crestal bone stress. And that concavely designed one may be used to reduce bone stress.
Axis, Cervical Vertebra
;
Dental Implants
;
Finite Element Analysis
;
Models, Theoretical

Result Analysis
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