Trends and research evolution in the Journal of Public Health Dentistry: A bibliometric analysis

INTRODUCTION

The Journal of Public Health Dentistry (JPHD) is a peer-reviewed international journal in community dentistry. This journal has a wide scope and focuses mainly on publishing original research articles including oral epidemiology, dental health services, public health practices, and policy development and assurance. This journal also aims to publish methods articles and review articles. The first issue was published in the year 1941. This journal publishes on behalf of the American Association of Public Health Dentistry which was founded in the year 1937. The publisher is Wiley-Blackwell, who is a signatory of the declaration on research assessment. According to the Scopus database, JPHD is featured in Q1 (Quartile 1) list and ranks 45/132 for the year 2023 under the Dentistry category and 264/665 under the Public Health, Environmental, and Occupational Health category. According to the Scopus database, the cite score for the year 2024 is 3 and Clarivate impact factor is 1.8.. The current editor-in-chief of JPHD is Dr. Robert J. Weyant who serves as professor and chair of the Department of Dental Public Health at the School of Dental Medicine, University of Pittsburgh, USA.

This bibliometric analysis is conducted to analyze the citation of scholarly publications. This helps in assessing the journal metrics which provide basic ideas on the intellectual structure of the journal, assessing the performance of scientific productions, and identifying the trending topics and its research components.^[1] The bibliometric analysis helps to conduct both subjective and objective analysis through performance analysis and scientific mapping.^[2] This bibliometric analysis was carried out for many highly cited journals in the field of dentistry to understand the global reach of dental research.^[3-5] Nath et al., conducted a bibliometric analysis of the Community Dentistry and Oral Epidemiology (CDOE) journal in the year 2023 which set the tone for us to conduct a bibliometric analysis on the JPHD journal.^[6] This study aims to analyze the trends and research evolution in JPHD through bibliometric analysis which specifically focuses on analyzing key research areas, citation impact, most prolific authors, universities, and countries. This provided a systematic analysis of scientific literature works using statistical techniques to analyze its contribution, impact, and progression of JPHD.

This article retrospectively analyses the journal’s significant contribution to the field of dental public and community health. This informs the editors about future research topics or authors to feature in the journal and evaluates the effectiveness of any changes in the editorial policies or publishing models. We have conducted both performance analysis and scientific mapping for this journal. The performance analysis aims to analyze the following data publication trends, citation trends, most cited papers, most cited authors, affiliation, and country. The scientific mapping tool comprises three frameworks – conceptual, intellectual, and social which aims to analyze the collaboration among authors, universities, and countries, co-citation of authors, keyword co-occurrence, prominent themes, and trending topics of this journal.

MATERIALS AND METHODS

The electronic search was carried out in the Scopus database which retrieved articles published between 1941 and 2024. The source title was “JPHD.” All the articles published in this journal were considered for analysis. The file was downloaded from the Scopus database in BibTex format. The dataset contained information about article type, author’s name, and affiliation, details of citation, abstract, and author’s keyword. The bibliometric analysis was carried out using R Studio “Bibliometrix” (University of Naples Federico II, Italy) package as well as “Biblioshiny web-based tool.”^[2]

The Biblioshiny Report is presented in Excel format titled “Biblioshiny report File.” [Supplementary Material] The descriptive data analysis was undertaken including the type of document, total publication per year to understand the publication pattern, the number of cited publications, and the total number of citations. The distribution of publications worldwide was shown through the world map. The author’s affiliation was traced and examined to determine the number of single-country publications (SCPs) and multi-country publications (MCPs). The contribution of the top 25 countries in JPHD was assessed. The total number of documents, total citation, and their progression over time were assessed. The top 25 universities with the most published documents and their production over time were identified.

The top 10 authors were assessed based on the number of documents published between 1941 and 2024. The most impactful authors were recognized based on their h-index, g-index, and m-index [Appendix A].^[7-10] Based on the citation count, the top 25 authors were identified. Lotka’s law was used to assess the author’s productivity by measuring the author’s publication frequency in JPHD.^[7] The number of global and within-journal citations received per year was calculated. It is used to measure the impact of publication. The top 25 references that were most cited by the authors of JPHD were assessed. The most frequently used keywords were also assessed. This helps to get an idea of the most trending topics in the journal. The three-field plot of the top 20 authors, keywords, and more productive countries was assessed.^[11]

Bibliometric network maps are used to visualize and explore the data. Network maps have three structural levels – social, conceptual, and intellectual. The collaboration networks among countries, institutions, and authors are shown by social network maps. It is shown by nodes/circles representing authors, countries, or institutions. The country map was constructed to understand the country’s collaboration in research. A collaboration of more than 5 times is shown in this map. The author’s commonly used keywords are shown by a cluster network map.^[12] Co-citation analysis was also carried out to show the number of papers that have cited a specific set of documents.^[13] Thematic map is a two-dimensional image which is based on its impact and centrality. This image is usually organized into four quadrants and a single circle represents themes. Factorial analysis of the author’s keyword is conducted to analyze the most critical topics in a journal. This factorial analysis is used to generate the conceptual map and topic dendrogram. A conceptual map is a distinct cluster of different topics but consists of documents which express the same and familiar concepts. The dendrogram is represented as a tree diagram which shows the association between objects and also shows how the clusters of corresponding analysis are arranged.^[14]

RESULTS

The search strategy, screening, and included studies are shown in Figure S1. The search was conducted in the Scopus database which retrieved 3982 articles. All articles were included in the analysis. The descriptive summary of publications in JPHD from 1941 to 2024 is presented in Table S1 and Appendix B. The total citation count of this journal is 44108 and the annual growth rate of this journal is 1.52. The overall cites per year were 0.51 and the cites per document were 10.17. The JPHD publications and citation patterns between 1941 and 2024 are presented in Table S2. Figure 1a shows the annual scientific production over time. The highest number of publications, with 91 articles was published in the year 1992. This was followed by 82 publications in the year 1988, 2011, and 2022. The highest number of mean citations per year was 2.01 which was in the year 2011. The second-highest mean citation per year was 1.86 in the years 2007 and 2011 [Figure 1b]. Most of the publications were from the USA, which was followed by Canada and Brazil [Figure 2a]. Among Asian countries, China records the highest number of publications. By the end of 2024, the USA had the highest total citation of 17078 with the average citation per article being 19.9. The second highest country was Canada with a total citation of 1936 and the average citation per article was 29.3 [Table S3 and Figure 2b]. A similar pattern was observed for the corresponding author’s country. The most productive country of corresponding authors was the USA which included 857 articles, SCP was 806, MCP was 51, and the SCP/MCP ratio was 15.80 [Table S4 and Figure 2c].

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Figure 1:

(a) The annual scientific production (b) The total citation count per year.

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Figure 2:

Trends in country and author’s production. (a) The country’s scientific production map. The dark blue color represents United States with most number of publications and the light blue color represents other nations with publications. (b) The country’s scientific production over time. (c) The most productive countries of the corresponding author. (d) The author’s production over time.

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The most prolific author was Horowitz AM with 66 published literature works and the second most prolific author was Rozeria RG with 44 publications. The maximum citation was by Horowitz AM which was 1424. The highest citation per year was by Rozeria RG with 319. The citation impact was highest for Burt BA. Levy SM and Warren JJ had the highest h-index of 19 with 41 publications and the first article was published in the year 1990 and 1995, respectively [Table S5 and Figure 2d]. Lotka’s law indicates that 77% of the authors contributed at least once and 11% of the contribution for the second time in the JPHD journal [Table S6]. The maximum contribution was by the University of IOWA with 224 publications followed by the University of North Carolina (139) and the University of California with 136 publications [Table S7]. Most highly impactful article was published by Borrelli B in the year 2011 with a total citation of 629 and the total citation per year was 41.93 [Table S8].^[15]

Table S9 shows the co-citation analysis which indicates that Horowitz AM was highly cited with 65 citations. At the global level, the most cited document was “Validation of self-reported oral health measures” which was published in the year 2002 and authored by Pitiphat et al.^[16] The most locally cited document was titled “Effectiveness of water fluoridation” which was authored by Newbrun and published in the year 1989 [Table S10].^[17] The most cited references by JPHD authors were titled “Oral Health in America: A Report of Surgeon General” which was published by the National Institute of Dental and Craniofacial Research in the year 2000. This article has received 92 citations by 2024 [Table S11].^[18] Table S12 shows the highly cited sources by authors of the JPHD journal. The highly cited source was the National Institute of Craniofacial Research with 106 articles being cited [Appendix C].^[19]

The most frequently used keywords were “Human” (2807 times), “United States” (1912 times), “Article” (1672 times), “Female” (1524 times), and “Male” (1454 times) [Table S13 and Figure S2]. The trending topic graphs represent the terms that appeared more than 5 times annually. In the past 5 years, the trending topics were “prevention and control,” “healthcare access,” “dental practices,” “COVID-19,” “Workforce,” “racism,” “ethnicity,” and “global health” [Figure S3]. The three-field plot also known as Sankey’s plot shows the relationship between the top 20 authors, affiliation, and keywords. The maximum association was found between Warren JJ, University of IOWA, and “dental caries” [Figure S4, Appendix D].^[20]

Figure 3a shows the author’s collaboration network map. The author’s collaboration was analyzed based on closeness and betweenness. The “betweenness” centrality captures the degree to which a particular vertex is located on the shortest pathways connecting other vertices. In simple words, it aids in finding people who act in a bridging capacity inside a network and significantly impacts the flow of information and ideas in the field. The “closeness” in centrality shows how these authors communicated with others during the collaboration.^[21] S. M. Levy, J. J. Warren, and B. Broffit (violet clusters) were strongly connected in the authors’ collaboration. Another group of collaboration was by G. D. Slade and J. D. Beck (Orange Clusters). The highest “betweenness” centrality was shown by Deborah Bailey McFall, Charles L. Milone, and William E. Cooley [Table S14]. The highest “closeness” centrality seen among collaborating authors was shown by Deoborah Bailey McFall, C. W. Douglass, William E. Cooley, R. G. Roseria, and R. A. Kutty [Table S15]. This collaboration network of authors helps us to understand the most influential direction of research in their field.

Figure 3b and Figure S5 show the collaboration network maps of the country. It was found that the USA had the highest number of collaborations. Figure 3c shows the structural observation of how research in this field has progressed. It highlights the most influential papers, the interconnected nature of different research themes, and the emergence of newer perspectives over time. The largest blue nodes, which represent the works by Russell, were the foundation for multiple future works.^[22] The green cluster shows the works by Kelly and Bruerd and Johnsen et al., with moderate influence.^[23,24] The red cluster shows the works of Levy et al., and Evans and Stamm, with less influence.^[25,26] The keyword co-occurrence map shows the relationship between commonly used keywords [Figure S6, Appendix E].

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Figure 3:

Scientific network map (a) Author’s collaboration network map. Colors spheres represent group of collaborators. (b) Country’s collaboration network map. The dark blue color represents United States with most number of publications and the light blue color represents other nations with publications. (c) Historiography.

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The University of IOWA contributed a maximum of 144 publications followed by the University of North Carolina (139 articles) and the University of California (136 articles). The least contribution was by the University of Adelaide with 59 publications [Figure 4]. Figure 5a shows the conceptual network map of keyword co-occurrence which is used to analyze the research trends in specific domains. The highly relevant themes are presented in the central region which is as follows: “dental procedure,” “healthcare delivery,” “dental health services,” “dentistry,” and “public health dentistry.” There is also broader distribution of terms such as “fluorides,” “methodology,” and “demography” which implies the field covers topics from treatment strategies to policy planning [Appendix F].

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Figure 4:

Most relevant affiliation.

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Figure 5:

Factorial analysis. (a) Conceptual structure. (b) Thematic map.

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The thematic map represents the topics that have been fundamental and core areas of the journal. This is based on the importance of the research field (centrality) and the development level of themes (density). These are divided into four quadrants which are as follows: Niche theme (Upper Left Quadrant), Motor themes (Upper Right Quadrant), Basic Themes (Lower Right Quadrants), and Emerging/Declining themes (Lower Left Quadrant). The topics such as “Humans,” “Dental caries,” “Female,” “Male,” “Adolescents,” “Child,” “Preschool,” “Article,” “Unites States,” and “Dentistry” were highly cited research (high density and low centrality). The highly relevant themes are “public health services” and “public health dentistry” which are represented in gray circle (high centrality and low density). The emerging/eclining themes were “history,” “medical history,” “healthcare organization,” “dental history,” “curriculum,” and “awards and prizes” [Figure 5b, Figure S7, Appendix F].

DISCUSSION

The main objective of this bibliometric analysis is to evaluate all the articles published in this journal from 1941 to 2024. This can provide valuable insights into the journal’s key research trends, themes, and most influential authors as well as affiliated institutes and collaboration networks.

Our research on JPHD indicated a significant contribution of JPHD to dental public health. The journals’ high impact factor has a valuable contribution to international literature. The highly cited article at the global level was “Validation of self-reported oral health measures” which is likely to influence the journal’s impact factor. The study also helps us to understand the less influential academic papers that can have a substantial impact while planning a public health policy.^[16] The article titled “The assessment, monitoring, and enhancement of treatment fidelity in public health clinical trial” by Borrelli, which was published in the year 2011 received the greatest impact among the peer researchers.^[15] Based on the highly cited corresponding author’s country, the USA had the most significant contribution. The USA also had a higher number of collaborations involving almost 45 countries. The USA had 2 collaborative works with India. The University of IOWA had given the maximum number of contributions while the University of Adelaide had less contribution comparatively. Our findings were in contrast to the study by Nath et al., where they reported that the University of Adelaide had a greater number of contributions in CDOE journals.^[6] Our research has focused on highly cited academic works often recognized beyond boundaries since they address significant research questions and innovative ideas. There is a tendency for authors to cite papers from their own country which is known as “the silo effect.” In our research, this effect was observed very little among highly cited papers.

Our study found that 77% of the authors were cited at least once followed by 11% of authors who were cited twice. Understanding the author’s contribution to the field of dental public health helps to identify their significant research impact, influence on academic works, and progress in the particular field of research. The keywords play an important role in conducting the literature search. The highly relevant keywords were “dental procedures,” “healthcare delivery,” “dental health services,” “dentistry,” and “public health dentistry” which indicates that this journal majorly focuses on publishing articles related to dental health and public health services as well as policies. The most relevant themes (motor themes) were highly influential and led to the significant progression of the journal in the field of dental public health. The basic themes such as “public health services” and “public health dentistry” were the foundation of this journal; still, further research has to be carried out for wider application. The emerging themes such as “healthcare organization” and “curriculum” are potential area of research to improve the healthcare organization, while the declining themes were “history,” “medical history,” and “dental history” which indicates its shift toward contemporary public health concerns.

There are a few strategies to improve the relevance of this journal which are as follows: (1) By prioritizing highly impactful research papers such as systematic reviews and meta-analyses and longitudinal studies with longer follow-ups; (2) enhancing its global collaboration by encouraging multinational studies, particularly focusing on regions such as Africa and Asia where there are large oral health disparities; (3) encouraging open-access policy and open-peer reviews; and (4) encouraging the research papers toward emerging or declining themes. This study had several strengths. First, this helps us to understand the fundamental themes pertaining to dental public health. Second, this helps us to track the evolution of research related to public health dentistry. Third, co-authorship and institutional collaboration identified its key contribution to interdisciplinary research. Fourth, the network analysis research patterns and interconnectivity led to the in-depth analysis of specific topics. This study significantly contributes to understanding the evolution of dental public health research and guides future publication strategies for JPHD.

There were a few limitations of this bibliometric analysis. (1) Only the Scopus database was used to conduct the search since it was a reliable database for citation analysis. This would have led to missing academic works that were not present in this database. (2) The retracted papers still received citations which led to distorting actual impact. (3) Recently published academic works may be underrepresented due to its delay in citation. (4) Altmetrics (alternative metrics) tracks new articles and policy documents that were excluded.

CONCLUSION

This bibliometric analysis significantly contributed to dental public health by JPHD. The use of advanced bibliometric tools for comprehensive data analysis provides valuable insights for future research. This journal is one of the high-impact journals in the field of public health dentistry. This research helped us to understand the impact of the journal’s metrics and citations. The key theme areas aid the researchers in deciding the most relevant topic for future research. The authors can increase the yield by focusing on underrepresented topics like healthcare organizations. Future research should focus on declining themes or emerging themes that can create a greater impact in the field of dental public health.