Yonsei University College of Dentistry Ranks 1st in Korea
Yonsei University College of Dentistry ranked 28th in the world and 1st in Korea, according to the 2023 QS World University Rankings for Dentistry. The QS rankings released on March 22, 2023, indicates that the Yonsei University College of Dentistry climbed 12 notches up from 40th in 2022.
The QS World University Rankings for Dentistry uses four methodologies with different weightings that are combined to produce the final result, which are as follows: ▲Academic reputation (30%), ▲Employer reputation (10%), ▲Citations per paper (30%), ▲H-index (30%). Yonsei University College of Dentistry scored 80.8 out of 100 for Citations per paper, indicating the high impact and quality of the scientific work done by university. We also scored 73.7 out of 100 for H-index, which measures the stability of impact and quality of the work published by the institution’s scientists and scholars.
Meanwhile, Yonsei University College of Dentistry ranked 32nd place in the world and 1st place in Korea in the clinical and health subject according to the THE (Times Higher Education) World University Rankings 2023. While rankings might be just numbers, these outstanding achievements imply that we should now focus on maintaining our stability and leading the way instead of trying to take the lead.
Launching of an E-Dental College
For the first time in the world, Yonsei University College of Dentistry established an E-Dental College on January 1, 2023 under the slogan of ‘College of Dentistry in my hand.’ This new initiative is aimed at providing alumni with greater access to dental education and resources with a focus on innovative, hands-on learning. About 200 online lectures that we produced over the last two years are available on LearnUS. The lectures cover a wide range of topics, including the latest dental knowledge and techniques, and are exclusively available to alumni.
Most of the classes were held online due to the pandemic, and we turned this circumstance into an opportunity to share the lectures with alumni. The funds raised by alumni who apply to E-Dental College will be used to provide a better educational environment for students and to support the treatment of low-income patients. By embracing technology and creating a more inclusive learning environment, Yonsei University College of Dentistry is taking a significant step towards improving dental education and patient care worldwide.
‘Research Excellence’ selection for Prof. Sung-Hwan Choi
A research project led by professor Sung-Hwan Choi of the Department of Orthodontics at Yonsei University College of Dentistry, which was supported by the the Korea Medical Device Development Fund (KMDF), has been selected as a ‘Research Excellence.’ Professor Choi has gained eligibility for follow-up support from KMDF for developing dental biomaterials that inhibit biofilm formation.
During the project, he developed a mixed material using PMEA (Poly 2-methoxyethyl acrylate), which is not easily contaminated with food, in order to compensate for the vulnerability of oral bacteria while maintaining the advantages of PMMA. He also introduced a modification of hybrid ionomer cements with polybetaine α-mZM to overcome the limitations of resin reinforced glass ionomer cement, which is extensively used in dental therapy but easily contaminated by bacteria.
Prof. Choi said, “If our technology for developing biofilm-inhibiting dental biomaterials can receive follow-up support from KMDF, there will be a good opportunity for our research outcome to enter the market. We plan to continue our efforts to apply our technology in clinical dentistry.”
YUCD Professors Elected as Full Members of National Academy of Medicine of Korea
Professor and Dean, Kee-Joon Lee and professor Baek Il Kim of Yonsei University College of Dentistry have been recently elected as full members of the National Academy of Medicine of Korea (NAMOK), a prestigious academic organization with a particular interest in medicine. Founded in 2004, NAMOK aims to promote continuous advancement of Korean medicine, as well as to contribute to the improvement of public health.
The National Academy of Medicine of Korea elects full members who have made significant contributions in medical fields including basic and clinical medicine, with over 20 years of research experience, publications in SCI journals, and other various academic achievements. This year, three new members out of 34 new full members were elected in the field of dentistry, which indicates that the contribution of dental research is highly appreciated in the entire medical field.
Discovery of Historical Record Reveals Existence of Korean Dental Specialists a Century Ago
Recently, a historical record that reveals the existence of Korean dental specialties a hundred years ago was discovered. On January 19, 1923, an advertisement for the Severance Dental Clinic by Dr. Taek-Ryong Lim was posted in the Dong-a Ilbo newspaper. It highlighted the clinic’s Departments of Orthodontics, X-rays, Oral Surgery, and General Dentistry. This advertisement serves as a proof that Korean dental specialists already existed a century ago, predating the current Korean dental specialist system established in 2008.
The origin of the Yonsei University College of Dentistry dates back to the year 1915, when American missionary dentist Dr. William J Scheifley established the first dental clinic at Severance Hospital in Korea. Since then, Severance Dental Clinic has played a significant role in the dental treatment and education in Korea. More than 25 Korean dentists, including Dr. Taek-Ryong Lim, trained at the Severance Dental Clinic, and built the foundation of Korean dental medicine. By providing the clinical training and research opportunities other institutions could not offer, Yonsei Dentistry has played a pivotal role in making Korean dentistry globally competitive.
Professor Yooseok Shin and Professor Junhewk Kim from Yonsei University College of Dentistry are currently searching for historical records to uncover dental treatments and social responsibilities of Korean dentists who worked at Severance Hospital during the Japanese colonial period.
1. Epithelial plasticity enhances regeneration of committed taste receptor cells following nerve injury
All animals, including humans, must consume food to survive; therefore, the taste is one of the most important senses, as it helps us consume nutritious food and avoid toxic foods. The tongue contains taste receptor cells embedded in onion-shaped structures called taste buds, which aid in detecting taste. These taste receptor cells have a turnover time of approximately two weeks and are continuously replaced. Previous studies have reported that Lgr5+ stem/progenitor cells are involved in the renewal and regeneration of taste receptor cells. This study has shown that, along with Lgr5+ stem/progenitor cells, a subset of differentiated taste receptor cells participates in regenerating taste receptor cells following injury by dedifferentiating into the progenitor-like cell. This study was published in the International Journal “Experimental and Molecular Medicine” (IF 12.172).
Anish Ashok Adpaikar, Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry (Postdoctoral researcher)
Jong-Min Lee, Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry
Hye-Yeon Cho, Yonsei University College of Dentistry (2nd year of dental school)
Han-Sung Jung, Division in Anatomy and Developmental Biology, Department of Oral Biology, Taste Research Center, Oral Science Research Center, BK21 FOUR Project, Yonsei University College of Dentistry
Abstract
Taste receptor cells are taste bud epithelial cells that are dependent upon the innervating nerve for continuous renewal and are maintained by resident tissue stem/progenitor cells. Transection of the innervating nerve causes degeneration of taste buds and taste receptor cells. However, a subset of the taste receptor cells is maintained without nerve contact after glossopharyngeal nerve transection in the circumvallate papilla in adult mice. Here, we revealed that injury caused by glossopharyngeal nerve transection triggers the remaining differentiated K8-positive taste receptor cells to dedifferentiate and acquire transient progenitor cell-like states during regeneration. Dedifferentiated taste receptor cells proliferate, express progenitor cell markers (K14, Sox2, PCNA) and form organoids in vitro. These data indicate that differentiated taste receptor cells can enter the cell cycle, acquire stemness, and participate in taste bud regeneration. We propose that dedifferentiated taste receptor cells in combination with stem/progenitor cells enhance the regeneration of taste buds following nerve injury.
2. Functional expression of oxytocin receptors in pulp-dentin complex
G-protein-coupled receptors (GPCRs) are the largest family of membrane proteins and play important roles in various pathogenesis and physiological regulation. Based on their functional diversity, GPCRs have been regarded as one of the main targets of the current pharmaceutical market. However, to date, drugs targeting GPCRs have not been developed to regenerate hard tissues, such as teeth and bones.
The oxytocin receptor (OXTR), a member of the G protein-coupled receptor (GPCR) superfamily, plays versatile roles in diverse biological contexts. The research team demonstrated the biological functions and significance of OXTR in dental pulp stromal cells (DPSCs) through a multidisciplinary approach. Microarray data of 494 GPCR genes revealed high OXTR expression in human DPSCs (hDPSCs). Blocking OXTR activity increased the expression of osteogenic and odontogenic marker genes, promoting hDPSC differentiation. Additionally, it was found that OXTR is involved in extracellular matrix (ECM) remodeling through the regulation of the gene expression related to ECM homeostasis. Based on the results, a preclinical experiment was performed using a dog pulpotomy model, demonstrating that the application of an OXTR inhibitor to damaged pulp induced significant larger amount of hard tissue formation.
These findings expand the knowledge about the biological role of OXTR beyond previously known contexts, such as smooth muscle cells in uterus and mammary glands as well as neurons in the central nervous system. In addition to OXTR, the research team expect to reveal a significant role of a new GPCR candidate in pulp-dentin complex through future research.
Dohyun Kim, Department of Conservative Dentistry, Yonsei University College of Dentistry
Jin Man Kim, Department of Oral Microbiology and Immunology, School of Dentistry, Seoul National University
Abstract
Dental pulp-derived stromal cells (DPSCs) are a crucial cell population for maintaining the tissue integrity of the pulp-dentin complex. The oxytocin receptor (OXTR), a member of the G protein-coupled receptor (GPCR) superfamily, plays versatile roles in diverse biological contexts. However, the role of OXTR in dental pulp has not yet been fully understood. Here, we demonstrate the biological functions and significance of OXTR in DPSCs through a multidisciplinary approach. Microarray data of 494 GPCR genes revealed high OXTR expression in human DPSCs (hDPSCs). Blocking OXTR activity increased the expression of osteogenic and odontogenic marker genes, promoting hDPSC differentiation. Additionally, we found that OXTR is involved in extracellular matrix (ECM) remodeling through the regulation of the gene expression related to ECM homeostasis. We further demonstrated that these genetic changes are mediated by trascriptional activity of Yes-associated protein (YAP). Based on the results, a preclinical experiment was performed using an animal model, demonstrating that the application of an OXTR inhibitor to damaged pulp induced significant hard tissue formation. These results provide new insight into the oxytocin-OXTR system in the regenerative process of pulp-dentin complex.
3. Cerium oxide nanozymes confer a cytoprotective and bio-friendly surface micro-environment to methacrylate based oro-facial prostheses
Therapy of intra-oral defects like cleft lip & palate includes use of oro-facial prosthetic appliances made of Poly(methyl methacrylate) (PMMA) resin. However, the patient mucosa is fragile and compromised which leads to recurrent trauma and infection causing chronic inflammatory lesions. The research team of Professors Sung-Hwan Choi (Department of Orthodontics) and Jae-Sung Kwon (Department and Research Institute of Dental Biomaterials and Bioengineering), along with post-doctoral research fellow Mangal Utkarsh (Department of Orthodontics), proposed an innovative solution to the inflammation prone mucosa by developing a cerium oxide nanozyme based acrylic resin, the i-PMMA. The i-PMMA offered (i) excellent cellular biocompatibility, (ii) was resistive to attachment of bacteria, and (iii) the nanoceria helped in exceptional reduction of cellular inflammation markers. These results suggested a breakthrough application of nanozyme in acrylic resin to deliver superior oral rehabilitation appliance. This study was published in the international peer-reviewed journal Biomaterials (Impact factor 15.304, JCR: Top 3%)' in February 2023.
Utkarsh Mangal, Department of Orthodontics, Institute of Craniofacial Deformity, Yonsei University College of Dentistry (First Author)
Jae-Sung Kwon, Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry (Corresponding author)
Sung-Hwan Choi, Department of Orthodontics, Institute of Craniofacial Deformity, Yonsei University College of Dentistry (Corresponding author)
Abstract
Poly-(methyl methacrylate) (PMMA) is the preferred biomaterial for orofacial prostheses used for the rehabilitation of naso-palatal defects. However, conventional PMMA has limitations determined by the complexity of the local microbiota and the friability of oral mucosa adjacent to these defects. Our purpose was to develop a new type of PMMA, i-PMMA, with good biocompatibility and better biological effects such as higher resistance to microbial adhesion of multiple species and enhanced antioxidant effect. The addition of cerium oxide nanoparticles to PMMA using a mesoporous nano-silica carrier and polybetaine conditioning, resulted in an increased release of cerium ions and enzyme mimetic activity, without tangible loss of mechanical properties. Ex vivo experiments confirmed these observations. In stressed human gingival fibroblasts, i-PMMA reduced the levels of reactive oxygen species and increased the expression of homeostasis-related proteins (PPARg, ATG5, LCI/III). Furthermore, i-PMMA increased the levels of expression of superoxide dismutase and mitogen-activated protein kinases (ERK and Akt), and cellular migration. Lastly, we demonstrated the biosafety of i-PMMA using two in vivo models: skin sensitization assay and oral mucosa irritation test, respectively. Therefore, i-PMMA offers a cytoprotective interface that prevents microbial adhesion and attenuates oxidative stress, thus supporting physiological recovery of the oral mucosa.