Research Trends in the <i>Journal of Dental Hygiene Science</i> Using Keyword Network Analysis and Topic Modeling: A Comparative Study of Pre- and Post-COVID-19 Periods (2015∼2024)

Background: As a multidisciplinary field, dental hygiene has seen the emergence of novel research topics that have reshaped its scholarly landscape during the pandemic.This study investigated the evolution of research themes and knowledge structures in the Journal of Dental Hygiene Science (JDHS) by comparing the pre-COVID-19 (20152019) and post-COVID-19 (20202024) periods.Methods: A total of 499 articles (319 from 20152019 and 180 from 20202024) published in JDHS were analyzed.Using NetMiner 5.0, meaningful keywords were extracted from titles, abstracts, and author keywords.Term frequency, term frequency-inverse document frequency, degree centrality, and betweenness centrality were examined.Topic modeling was conducted using the Latent Dirichlet Allocation algorithm.Results: During 20152019, "student," "stress," "health," and "tooth" showed high degree centrality, with eight topics identified: education and clinical practice satisfaction, oral health behaviors, job stress, teeth and oral tissues, professional identity, core competencies, preventive research, and factor analysis.In 20202024, "tooth," "work," and "surface" demonstrated the highest degree centrality, with five reconfigured topics: dental hygienist competencies, infection control, biofilm and material-related experimental research, and oral health behaviors.Notably, "COVID-19," "infection," "control," and "hand hygiene" emerged as an independent topic cluster.Across both periods, "health" and "dental hygienist" maintained high betweenness centrality, serving as bridging concepts across research domains.Conclusion: Over the past decade, JDHS research has shifted from an education-and psychology-oriented focus to clinical and experimental studies, with infection control emerging as an independent research theme after COVID-19.However, internationally prominent topics such as teledentistry and digital dentistry remain underrepresented, suggesting the need for expanded research in these emerging areas.This study provides quantitative evidence of structural changes in Korean dental hygiene research, offering insights to guide future research directions and journal development strategies.