1.Host modulation therapy for improving the osseointegration of dental implants under bone healing-suppressed conditions: a preclinical rodent-model experiment
Young Woo SONG ; Jin-Young PARK ; Yoon-Hee KWON ; Wooyoung Eric JANG ; Sung-JinSung-Jin KIMKIM ; Jeong Taeg SEO ; Seok Jun MOON ; Ui-Won JUNG
Journal of Periodontal & Implant Science 2024;54(3):177-188
Purpose:
Placing dental implants in areas with low bone density or in conditions where bone healing is suppressed is challenging for clinicians. An experiment using a rodent model was performed with the aim of determining the efficacy of host modulation by increasing the systemic level of cholesterol sulfate (CS) using Irosustat in the context of the bone healing process around dental implants.
Methods:
In 16 ovariectomised female Sprague-Dawley rats, 2 implant fixtures were placed in the tibial bones (1 fixture on each side). At 1 week after surgery, the high-CS group (n=8) received Irosustat-mixed feed, while the control group (n=8) was fed conventionally. Block specimens were obtained at 5 weeks post-surgery for histologic analysis and the data were evaluated statistically (P<0.05).
Results:
Unlike the high-CS group, half of the specimens in the control group demonstrated severe bone resorption along with a periosteal reaction in the cortex. The mean percentages of bone-to-implant contact (21.5%) and bone density (28.1%) near the implant surface were significantly higher in the high-CS group than in the control group (P<0.05), as was the number of Haversian canals (by 5.3).
Conclusions
Host modulation by increasing the CS level may enhance the osseointegration of dental implants placed under conditions of impaired bone healing.
2.Implant Thread Shape Classification by Placement Site from Dental Panoramic Images Using Deep Neural Networks
Sujin YANG ; Youngjin CHOI ; Jaeyeon KIM ; Ui-Won JUNG ; Wonse PARK
Journal of implantology and applied sciences 2024;28(1):18-31
Purpose:
In this study, we aimed to classify an implant system by comparing the types of implant thread shapes shown on radiographs using various Convolutional Neural Networks (CNNs), particularly Xception, InceptionV3, ResNet50V2, and ResNet101V2. The accuracy of the CNN based on the implant site was compared.
Materials and Methods:
A total of 1000 radiographic images, consisting of eight types of implants, were preprocessed by resizing and CLAHE filtering, and then augmented. CNNs were trained and validated for implant thread shape prediction. Grad-CAM was used to visualize class activation maps (CAM) on the implant threads shown within the radiographic image.
Results:
Averaged over 10 validation folds, each model achieved an AUC of over 0.96: AUC of 0.961 (95% CI 0.952–0.970) with Xception, 0.973 (95% CI 0.966-0.980) with InceptionV3, 0.980 (95% CI 0.974-0.988) with ResNet50V2, and 0.983 (95% CI 0.975-0.992) with ResNet101V2. Accuracy was higher in the posterior region than in the anterior area in all four models. Most CAMs highlighted the implant surface where the threads were present; however, some showed responses in other areas.
Conclusion
The CNN models accurately classified implants in all areas of the oral cavity according to the thread shape, using radiographic images.
3.Implant Thread Shape Classification by Placement Site from Dental Panoramic Images Using Deep Neural Networks
Sujin YANG ; Youngjin CHOI ; Jaeyeon KIM ; Ui-Won JUNG ; Wonse PARK
Journal of implantology and applied sciences 2024;28(1):18-31
Purpose:
In this study, we aimed to classify an implant system by comparing the types of implant thread shapes shown on radiographs using various Convolutional Neural Networks (CNNs), particularly Xception, InceptionV3, ResNet50V2, and ResNet101V2. The accuracy of the CNN based on the implant site was compared.
Materials and Methods:
A total of 1000 radiographic images, consisting of eight types of implants, were preprocessed by resizing and CLAHE filtering, and then augmented. CNNs were trained and validated for implant thread shape prediction. Grad-CAM was used to visualize class activation maps (CAM) on the implant threads shown within the radiographic image.
Results:
Averaged over 10 validation folds, each model achieved an AUC of over 0.96: AUC of 0.961 (95% CI 0.952–0.970) with Xception, 0.973 (95% CI 0.966-0.980) with InceptionV3, 0.980 (95% CI 0.974-0.988) with ResNet50V2, and 0.983 (95% CI 0.975-0.992) with ResNet101V2. Accuracy was higher in the posterior region than in the anterior area in all four models. Most CAMs highlighted the implant surface where the threads were present; however, some showed responses in other areas.
Conclusion
The CNN models accurately classified implants in all areas of the oral cavity according to the thread shape, using radiographic images.
4.Implant Thread Shape Classification by Placement Site from Dental Panoramic Images Using Deep Neural Networks
Sujin YANG ; Youngjin CHOI ; Jaeyeon KIM ; Ui-Won JUNG ; Wonse PARK
Journal of implantology and applied sciences 2024;28(1):18-31
Purpose:
In this study, we aimed to classify an implant system by comparing the types of implant thread shapes shown on radiographs using various Convolutional Neural Networks (CNNs), particularly Xception, InceptionV3, ResNet50V2, and ResNet101V2. The accuracy of the CNN based on the implant site was compared.
Materials and Methods:
A total of 1000 radiographic images, consisting of eight types of implants, were preprocessed by resizing and CLAHE filtering, and then augmented. CNNs were trained and validated for implant thread shape prediction. Grad-CAM was used to visualize class activation maps (CAM) on the implant threads shown within the radiographic image.
Results:
Averaged over 10 validation folds, each model achieved an AUC of over 0.96: AUC of 0.961 (95% CI 0.952–0.970) with Xception, 0.973 (95% CI 0.966-0.980) with InceptionV3, 0.980 (95% CI 0.974-0.988) with ResNet50V2, and 0.983 (95% CI 0.975-0.992) with ResNet101V2. Accuracy was higher in the posterior region than in the anterior area in all four models. Most CAMs highlighted the implant surface where the threads were present; however, some showed responses in other areas.
Conclusion
The CNN models accurately classified implants in all areas of the oral cavity according to the thread shape, using radiographic images.
5.Intensive Surveillance for Women With Breast Cancer: A Multicenter Retrospective Study in Korea
Sungmin PARK ; Hyeong-Gon MOON ; Jong Won LEE ; Ku Sang KIM ; Zisun KIM ; So-Youn JUNG ; Jihyoun LEE ; Se Kyung LEE ; Byung Joo CHAE ; Sung Ui JUNG ; Jung Whan CHUN ; Jong-Ho CHEUN ; Hyun Jo YOUN
Journal of Breast Cancer 2024;27(4):235-247
Purpose:
This study evaluated the effectiveness of different surveillance intensities on morbidity and mortality in women with breast cancer.
Methods:
This retrospective study included patients who had undergone breast cancer surgery in the Republic of Korea between 2009 and 2011. The patients were divided into two groups based on the intensity of their postsurgical surveillance: intensive surveillance group (ISG) and less-intensive surveillance group. Surveillance intensity was measured based on the frequency and type of follow-up diagnostic tests conducted, including mammography, ultrasonography, computed tomography, magnetic resonance imaging, bone scans, and positron emission tomography scans.
Results:
We included 1,356 patients with a median follow-up period of 121.2 months (range, 12.8–168.0 months). The analysis revealed no significant difference in the overall survival (OS) between the two groups within five years of surgery. However, patients with ISG exhibited significantly better breast cancer-specific survival (BCSS) and distant metastasisfree survival (DMFS) within the same period. Five years after surgery, the differences in survival outcomes between the groups were not statistically significant.
Conclusion
Intensive surveillance did not demonstrate a significant improvement in OS for patients with breast cancer beyond five years postoperatively. However, within the first five years, intensive surveillance was associated with better BCSS and DMFS. These findings suggest that personalized surveillance strategies may benefit specific patient subsets, particularly in the early years after treatment. Further nationwide randomized studies are warranted to refine surveillance guidelines and optimize outcomes in patients with breast cancer.
6.Revised evaluation objectives of the Korean Dentist Clinical Skill Test: a survey study and focus group interviews
Jae-Hoon KIM ; Young J KIM ; Deuk-Sang MA ; Se-Hee PARK ; Ahran PAE ; June-Sung SHIM ; Il-Hyung YANG ; Ui-Won JUNG ; Byung-Joon CHOI ; Yang-Hyun CHUN
Journal of Educational Evaluation for Health Professions 2024;21(1):11-
Purpose:
This study aimed to propose a revision of the evaluation objectives of the Korean Dentist Clinical Skill Test by analyzing the opinions of those involved in the examination after a review of those objectives.
Methods:
The clinical skill test objectives were reviewed based on the national-level dental practitioner competencies, dental school educational competencies, and the third dental practitioner job analysis. Current and former examinees were surveyed about their perceptions of the evaluation objectives. The validity of 22 evaluation objectives and overlapping perceptions based on area of specialty were surveyed on a 5-point Likert scale by professors who participated in the clinical skill test and dental school faculty members. Additionally, focus group interviews were conducted with experts on the examination.
Results:
It was necessary to consider including competency assessments for “emergency rescue skills” and “planning and performing prosthetic treatment.” There were no significant differences between current and former examinees in their perceptions of the clinical skill test’s objectives. The professors who participated in the examination and dental school faculty members recognized that most of the objectives were valid. However, some responses stated that “oromaxillofacial cranial nerve examination,” “temporomandibular disorder palpation test,” and “space management for primary and mixed dentition” were unfeasible evaluation objectives and overlapped with dental specialty areas.
Conclusion
When revising the Korean Dentist Clinical Skill Test’s objectives, it is advisable to consider incorporating competency assessments related to “emergency rescue skills” and “planning and performing prosthetic treatment.”
7.Periosteum-attached Autogenous Block Bone Graft with Simultaneous Implant Placement on the Anterior Maxilla: A Case Report
Seung-Hyun PARK ; Jongseung KIM ; Ui-Won JUNG ; Jae-Kook CHA
Journal of Korean Dental Science 2024;17(2):64-74
This case report presents the long-term radiographic outcomes of a novel approach for simultaneous lateral augmentation and implant surgery. A 60-year-old male patient who required tooth extraction of the maxillary central and lateral incisors due to trauma visited the clinic. After tooth extraction, severe horizontal and vertical deficiencies occurred owing to atrophy of the alveolar ridge, and a simultaneous guided bone regeneration (GBR) procedure was planned along with the installation of two implants. In the present case, a modification of the conventional ‘sandwich technique’ was used by placing the mixture of autogenous bone chips and xenografts at the outermost layer to maximize the osteogenic potential at the coronal part of augmentation while applying solely xenografts at the inner layer. To enhance volumetric stability, an autogenous block of periosteum harvested from the maxillary tuberosity was incorporated between the two layers. Cone-beam computed tomography was performed at baseline and 3 years after the surgery to compare radiographic outcomes. Dehiscence after fixture installation was successfully observed at the re-entry of the surgery site. Three years after the surgery, average horizontal bone gains of 6.11 mm and 4.12 mm were observed in the maxillary central and lateral incisor areas, respectively. Healthy peri-implant mucosa and well maintained marginal bone levels were observed 8 years after the surgery, meeting the criteria for implant success. The findings of this case suggest that a substantial amount of horizontal bone gain can be obtained with a layered approach using autogenous bone materials and xenografts, highlighting the advantages of incorporating autogenous blocks into the simultaneous GBR procedure.
8.Effects of a modified surgical protocol on the positional accuracy of dental implants placed using fully guided implant surgery in the partially edentulous posterior ridge with distal extension: a dentiform model study
Young Woo SONG ; Seung Ha YOO ; Ui-Won JUNG
The Journal of Advanced Prosthodontics 2024;16(1):1-11
PURPOSE:
The present experiment aimed to evaluate the placement accuracy of fully guided implant surgery using a mucosa-supported surgical guide when the protocol of osteotomy and installation was modified (MP) compared to when the protocol was sequentially and conventionally carried out (CP).
MATERIALS AND METHODS:
For 24 mandibular dentiform models, 12 dentists (6 experts and 6 beginners) performed fully guided implant placements two times at the right first and second molar sites using a mucosa-supported surgical guide, once by the CP (CP group) and at the other time by the MP (MP group). The presurgical and postsurgical stereolithographic images were superimposed, and the deviations between the virtually planned and actually placed implant positions and the procedure time were compared statistically (P < .05).
RESULTS:
The accuracies were similar in the CP and MP groups. In the CP group, the mean platform and apex deviations at the second molar site for the beginners were +0.75 mm and +1.14 mm, respectively, which were significantly larger than those for the experts (P < .05). In the MP group, only the mean vertical deviation at the second molar site for the beginners (+0.53 mm) was significantly larger than that for the experts (P < .05). The procedure time was significantly longer for the MP group (+94.0 sec) than for the CP group (P < .05).
CONCLUSION
In fully guided implant surgery using a mucosa-supported guide, the MP may improve the placement accuracy when compared to the CP, especially at sites farther from the most-posterior natural tooth.
9.The Impact of Masticatory Function on Cognitive Impairment in Older Patients:A Population-Based Matched Case-Control Study
Kyung-A KO ; Jin-Young PARK ; Jung-Seok LEE ; Byoung Seok YE ; Ui-Won JUNG ; Seong-Ho CHOI ; Jae-Kook CHA
Yonsei Medical Journal 2022;63(8):783-789
Purpose:
The aim of this study was to investigate the association between the changes in masticatory function and cognitive impairment by analyzing longitudinal data of older Korean patients.
Materials and Methods:
Patients aged over 60 years with dental records between 2005 to 2010 (baseline; T1) and 2014 to 2020 (follow-up; T2) were selected in a single medical center. Based on the dementia diagnosis after T2, the cohort was classified into two groups, the dementia group (n=122) and the control group (n=366). Changes in masticatory function were calculated using the total functional tooth unit (T-FTU) in both groups. The incidence of tooth extraction (%) and the subsequent rehabilitation during the observation period were also evaluated.
Results:
In the dementia group, T-FTU significantly decreased from T1 to T2 (9.81±2.78 to 9.11±3.16, respectively, p=0.008), while no significant change was observed in the control group. During the mean observation period of 9 years, significantly more teeth were extracted and neglected to be prosthetically restored in the dementia group than in the control group. Regression analysis revealed that the number of missing teeth neglected [odds ratio (OR)=1.195, 95% confidence interval (CI)=1.025–1.393, p=0.023] and previous alcohol consumption (OR=4.445, 95% CI=1.831–1.795, p=0.001) were the most significant risk factors of dementia.
Conclusion
There might be a causative relationship between the neglected missing dentition and the onset of dementia.
10.Ultrasound Findings were Associated With Radiographic Changes, But Not Clinical and Functional Outcomes in Hand Osteoarthritis
Seong-Kyu KIM ; Ui Hong JUNG ; Ji-Won KIM ; Jung-Yoon CHOE
Journal of Rheumatic Diseases 2021;28(1):17-24
Objective:
. There is a debate over the relevance of ultrasound abnormalities to the pain, functional impairment, and radiologic severity in hand osteoarthritis (OA). This study aims to determine the association between ultrasound abnormalities and clinical, functional, and radiographic measures in hand OA.
Methods:
. A total of 66 patients was consecutively enrolled. All patients with gray-scale synovitis, joint effusion, and osteophytes were examined by ultrasound for 20 hand joints. Radiographic changes in both hands were evaluated by the Kellgren-Lawrence (K-L) grading system and were described as total radiographic severity score and number of affected joints. Other measures were also assessed, including each patient’s visual analogue scale for pain, the Functional Index for Hand Osteoarthritis for functional disability, and grip and pinch strength for hand muscle strength.
Results:
. In total, 10 patients with gray-scale synovitis, 35 with joint effusion, and 66 with osteophytes were detected in hand OA scans on ultrasound. Osteophytes on ultrasound were significantly associated with total radiographic severity score and number of affected joint (r=0.293, p=0.003 and r=0.336, p<0.001, respectively). In addition, there were weak associations of synovitis and joint effusion with radiographic changes. Patients with higher total radiographic severity score showed larger number of ultrasound-detected abnormalities, such as synovitis, joint effusion, and osteophytes (p=0.011, p=0.002, and p<0.001, respectively).
Conclusion
. This study shows that ultrasound findings, especially osteophytes, were associated with radiographic changes based on K-L grade, but not clinical and functional status in hand OA.

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