Introduction
Dentistry is a continuously advancing field in which socioeconomic changes and new scientific technologies are rapidly integrated to improve oral hygiene and quality of life in patients through the application of new research [1]. Research in pediatric dentistry is uniquely segmented, as children are constantly growing and have a limited ability to manage oral hygiene independently. Consequently, pediatric dentistry has evolved into a discipline that encompasses all areas of dentistry, including orthodontics, restorative dentistry, and surgery.
Changes in dentistry are often reflected in published studies, making it helpful to investigate changes in study trends within specific academic areas and explore new concepts for future research [2]. These efforts have been extensive, broadly across dentistry and in specific areas [3-10]. Understanding research trends in pediatric dentistry in particular can provide useful guidance for adapting practices to benefit children. Nainar et al. [11] examined research trends in the Pediatric Dentistry (PD) and Journal of Dentistry for Children, both published by the American Academy of Pediatric Dentistry, from 1969 to 1998, focusing on study design. Ohta et al. [1] tracked changes in topics and impact factors in research published in the PD from 1999 to 2018.
Nearly two centuries have passed since dentistry was first introduced to South Korea. Although the domestic industry has significantly advanced, a substantial dependence on foreign techniques and materials remains. While numerous studies have analyzed trends in academic research in pediatric dentistry journals abroad [12-14], similar research focusing on pediatric dentistry in Korea in the 21st century is lacking. Kim et al. [2] conducted a study on research trends in the Journal of the Korean Academy of Pediatric Dentistry (JKAPD) from 1974 to 2001, analyzing 956 articles based on their main theme, chronological distribution, and thematic distribution. They found that research on dental caries and systemic disorders represented a relatively high proportion of the studies. They also noted an increase in research on dental materials and equipment, a decrease in research on space management and tooth development, and a low distribution of research on behavioral science and oral habits. However, no follow-up study has been conducted in Korea since then. The JKAPD has published its 51st volume since its inception in 1974 and continues to play a pioneering role in domestic clinical and scientific research. Notably, since July 2023, all manuscripts have been submitted in English, and many scholars have been working to improve the journal’s international profile. Nevertheless, research trends are not well organized, indicating the need for an updated study.
Many international pediatric dental journals represent their respective regions. The Japanese Journal of Pediatric Dentistry (JJPD), published by the Japanese Society of Pediatric Dentistry, and PD, published by the American Academy of Pediatric Dentistry, are considered leading publications in this field[15]. The European Journal of Paediatric Dentistry, published by the Italian Society of Paediatric Dentistry, and the International Journal of Paediatric Dentistry, published by the International Association of Pediatric Dentistry and the British Society of Paediatric Dentistry, are also highly respected journals globally. In addition, the European Academy of Paediatric Dentistry began publishing the European Archives of Paediatric Dentistry (EAPD) in 2006, introducing many innovative studies. The Journal of Clinical Pediatric Dentistry, published by the MRE press, also releases issues monthly featuring numerous studies that are referenced in domestic research and are evolving in tandem.
Advances in technology have enabled research to be shared and accessed globally, leading to a remarkable evolution in the field of pediatric dentistry. Nevertheless, research directions may vary based on the culture and policies of each country. Thus, analyzing contemporary trends in submitted studies across several pediatric dental journals will be helpful for comparing and analyzing trends in domestic and international research and provide an opportunity to review which social and environmental changes have influenced them. In this study, we aimed to classify studies published in the JKAPD from 2004 to 2023 by topic to identify changes in research trends and compare them with those of other international journals to elucidate differences.
Materials and Methods
1. Data collection
Based on recent research, the data collection period was set to include journals published in the last 20 years [1]. To select the academic journals for this study, we first considered the main journals of the societies representing each region, similar to the JKAPD. Based on previous studies, we selected academic journals from the Korean, American, and Japanese pediatric dentistry societies as the primary literature [2,15]. Additionally, we included a European journal, in which research papers have been actively published recently, to differentiate this study from prior ones. Among the many pediatric dental journals, we selected the four journals for our study because they are the main pediatric dental journals with the highest volume of published research (Table 1). Data from the JKAPD were gathered by referring to articles published over 20 years from 2004 to 2023, currently archived in Korea Science (https://koreascience.kr/) provided by the Korea Institute of Science and Technology Information. During the same period, data for the PD, EAPD, and JJPD were collected from Ingenta (https://www.ingentaconnect.com/), Springer (https:/link.springer.com/), and J-Stage (https://www.jstage.jst.go.jp/), respectively. Articles not written in English or Korean were excluded from this study. Additionally, abstracts, academic sessions, editorials, letters and comments, and special reports were excluded from the PD.
2. Establishment of classification criteria
Indicators from previous studies were referenced to establish the classification criteria; however, discrepancies with contemporary trends have been observed [1,2,11,15]. Ultimately, 16 classification criteria were determined by referring to the index of the textbook of Korean pediatric dentistry (Table 2). Each criterion was assigned a number, and all articles were categorized according to the classification numbers. A well-trained investigator performed the classification. The titles of the studies were selected as the primary criteria for division. If the research subject was unclear, the appropriate category was determined by consulting the abstract, introduction, and conclusion of the original text.
3. Data distribution
Categorized data were summarized according to journal, period, and topic using Excel 2016 (Microsoft Corp., Redmond, WA, USA).
1) Number of published papers
The number of articles published annually in each journal was also recorded. This was organized chronologically to confirm the increase or decrease in the number of papers published by the four journals.
2) Thematic distribution
The distribution of topics published by each journal over the past 20 years was presented in percentiles. This allowed for a comparison of publishing trends with studies conducted before and after 2004. Additionally, to examine changes in distribution within the study period, the data were divided into 4-year intervals to observe the variations over time.
3) Research trends
The number of articles published in each journal was categorized by subject to assess which journals have the most active publications across various criteria. This analysis also aimed to track the increase or decrease in publications on specific subjects within each journal over time.
4) Research focus on specific topic
As the distribution criteria used in this study were comprehensive, specific keywords designated by the researcher were separately searched and categorized to examine publication trends on more detailed topics. This analysis was conducted according to year and journal to identify the increase or decrease in the number of studies published that may not have been evident in broader classifications.
4. Statistical analysis
Statistical analyses were performed using SPSS Statistics 20 (IBM Corp., Armonk, NY, USA). The Pearson correlation coefficient was calculated to assess the correlation between thematic distributions across journals. It was summarized as a correlation coefficient matrix, and the p values were obtained using the Student’s t-test. Simple linear regression analysis was used to clarify the relationship between the total number of articles and the number of studies by subject. One hundred articles were randomly selected from each journal and re-evaluated after 4 weeks to assess intra-rater reliability.
Results
1. Number of published articles
A total of 1,205 articles published in 20 volumes of the JKAPD between 2004 and 2023 were included in this study. Additionally, 1,320 articles from the PD and 636 articles from the JJPD were included. Since the EAPD began publication in 2006, 1,070 articles published between 2006 and 2023 were targeted.
The number of articles published per year in each journal is shown in Fig. 1. The journal that released the most research over the past 20 years was the PD. The JKAPD was the most active in presentations during the early 2000s, publishing 339 articles from 2004 to 2007. However, the EAPD recently published the largest number of studies, with 363 articles published between 2020 and 2023, despite being a latecomer. The JJPD published the fewest studies among the included journals.
2. Thematic distribution
Fig. 2 presents the total distribution by subject of all published studies since 2004, showing the percentage of research topics in each journal. According to the graphs, studies on behavioral science accounted for the lowest proportion in the JKAPD (1.1%). In contrast, studies on conservative treatment (12.9%) and orthodontics (7.6%) were published more frequently in the JKAPD than in other journals. Table 3 shows the correlation matrices for each journal. Research trends in the PD and EAPD exhibited similar tendencies (0.884); however, differences were noted in the fields of dental growth and developmental disturbances. The JJPD showed research trends different from those of the other journals, which were more focused on sleep disturbance and muscular dysfunction (5.7%) but neglected restoration and pulp treatment.
3. Research trends
Research trends in the four journals by subject are displayed in Fig. 3. The EAPD, which has recently published a large number of studies, demonstrated an increasing number of studies across almost all topics. Orthodontic treatment and eruption disturbance are the most frequently studied topics in Korea. In the JJPD, research on cleft lip and palate and dental equipment was notably prominent, but is now rarely studied. A simple linear regression analysis was performed to determine whether the fluctuations in the total number of articles and the number of papers per topic were correlated.
Publication trends by period are displayed in Fig. 4. Dental caries and prevention of dental caries were the most published topics in all journals (15.4%), followed by systemic disease or patients with special health care needs (SHCN) (9.9%), conservative treatment and restorative materials (9.2%), and dental growth and developmental disturbances (8.8%).
4. Research focusing on specific topics
The results of the classification of articles by specific keywords are presented in Fig. 5. In the JKAPD, supernumerary teeth (SNT) emerged as a prominent research topic in Korea compared to other regions. Crown restoration and quality-of-life surveys were the most studied fields in the PD and EAPD, respectively.
5. Reliability test
The intraclass correlation coefficient values ranged from 0.95 to 0.99, indicating high reliability (Table 5, p < 0.05).
Discussion
In this study, we reviewed the typology of evidence and publishing tendencies in four journals from 2004 to 2023. Our results highlight broader trends in contemporary pediatric dentistry and provide findings in comparison with those of previous studies [2,15]. In this study, the increased research output of the JKAPD is reflected with 249 more articles compared with that of Kim et al.’s study [2]. Furthermore, the number of articles published in the PD has nearly doubled compared to that reported in previous studies; in contrast, the number of studies published in the JJPD has decreased.
A comparison of the findings of previous studies with those of the current research reveals similarities in trends before and after the 21st century. The publication trends of the JKAPD remain consistent with publishing articles on seven of the top eight topics, though in a different order [2]. Similarly, the PD and JJPD had published articles on the same four and three of the top five subjects, respectively [15]. Additionally, when compared with the research topics of a recent article [1], the top three research topics identified in the present study remained consistent, confirming that cariology, systemic diseases, and restorative treatment have been the most active areas of research in pediatric dentistry, from past to present [1]. In this study, the JKAPD had been found to publish fewer studies on systemic diseases or patients with SHCN compared to other journals, whereas many studies on conservative treatment and restorative materials had been found to be published, which seems similar to the distribution of topics in Brazil reported by Poletto et al. [14].
Pearson correlation coefficient analysis was conducted to assess the similarity of article topic distributions across the journals. The PD and EAPD showed a high similarity, whereas the JJPD showed a low similarity. The category of dental growth and developmental disturbances ranked high in the EAPD but low in the PD. In this study, research topics such as molar-incisor hypomineralization (MIH) were typically included in subject distribution. As reported in a previous study, MIH is a highly prevalent topic published in European journals [16]. This is because tooth development disorders are mostly congenital, making early diagnosis and treatment by pediatric dentists crucial while patients are still young [17]. The increase in the number of studies on this topic in the EAPD reflects this aspect.
The differentiation in publication tendencies in the JJPD may be attributed to the bifurcation of academic journals. The Japanese Society of Pediatric Dentistry launched the Pediatric Dental Journal, which primarily targets international readers and publishes research in English. This journal includes a significant amount of research on conservative and endodontic treatments. The decrease in the number of studies published in the JJPD compared to previous studies may be attributed to this shift[15]. Because the treatment of dental caries is a topic of global interest, it is speculated that researchers prefer publishing in international journals rather than domestic ones.
By contrast, articles published in the JJPD showed a high percentage of research topics that were not well covered in other journals because they targeted the domestic market. For example, this study revealed that articles on oral muscles and the temporomandibular joint have frequently been published in the JJPD [15]. Weakness in oral muscle strength such as bite force or tongue pressure has been shown to cause abnormal maxillofacial growth and malocclusion [18,19]. Many orthodontists have become interested in myofunctional therapy to correct or prevent malocclusion [20]. Breathing and digestive problems related to oral diseases can cause systemic changes, including growth inhibition or delays in intelligence development [21]. Perhaps the field of oral medicine is a new frontier in pediatric dentistry, and the JJPD might be at the forefront.
As one of the most respected academic journals in pediatric dentistry, the PD has published the largest number of articles on various topics over the past 20 years. In particular, they often combined articles with relatively low occupancy rates and published them together, such as dental trauma in 2009 and behavior management in 2014. It is important to highlight these issues as dental guidelines are often modified with reference to them.
The EAPD was established later than the other journals discussed in this study; however, it is currently one of the leading journals publishing research in pediatric dentistry. Most data indicate an increasing trend in the number of articles. Notably, the number of survey studies related to the quality of life, particularly focusing on caries treatment, sedation, and general anesthesia, have increased [22,23]. Children’s dental experiences are crucial for their future cooperation and oral hygiene management. This study revealed that few studies in Korea have evaluated these experiences using objective criteria. Recently, with a growing interest in children’s rights, Korean textbooks have added new chapters reflecting this aspect. Therefore, it is necessary for Korea to follow this trend in pediatric dentistry research.
Notably, articles on systemic diseases and patients with SHCN in the JKAPD were ranked lower than those in other journals, which might be related to the composition of the members of the Korean Association for Disability and Oral Health. Dentistry for patients with SHCN has become a field of interest in pediatric dentistry in most developed countries. It was introduced in Korea by a pediatric dentist in the 1990s, and to this day, academic education and clinical treatment are managed by the Department of Pediatric Dentistry [24]. In response, the Korean Association for Disability and Oral Health was established in 2004, serving as a platform for research and knowledge sharing on dental care for patients with SHCN [25]. Since many articles on pediatric dentistry and dentistry for patients with SHCN in Korea are often written by the same authors, the proportion of these topics in this study might be relatively lower than that in other pediatric dental journals [26].
Despite the decreasing birth rate in Korea, attention and research on patients with systemic diseases or SHCN are needed in pediatric dentistry. The field of dentistry for patients with SHCN includes those with physical disabilities, intellectual disabilities, congenital defects, metabolic and systemic diseases, seizure disorders, sensory impairments, hemophilia, tumors, and other medical conditions classified by the World Health Organization, as well as the older adults who require special medical treatment or management [26]. Additionally, it includes young children with behavioral management issues during dental treatment and individuals with extreme dental phobia or anxiety. With the increasing number of people with SHCN and older adults in South Korea, the demand for dental care is increasing [27].
A simple linear regression analysis revealed a correlation between the total number of articles and the number of articles by subject. Interestingly, a statistically significant proportional relationship was found in all journals for pulp treatment and filling materials. Studies on mineral trioxide aggregates are among the most timely publication topics, with a steady stream of research. The publication tendency with the largest positive correlation were articles on dental caries (0.766) and systemic diseases (0.722) in the JKAPD (Table 4). As these are the most published topics in pediatric dentistry, they are consistently published in domestic journals regardless of the year. By tracking the trends in these topics, it may be possible to estimate the overall volume of publications in pediatric dentistry.
Similar to previous studies, dental caries and its prevention were the most frequently published topics noted in this study [1,14,15]. Considering that dental caries remain one of the most prevalent chronic conditions in children, necessitating a significant amount of pediatric dental care, it is unsurprising that the diagnosis and prevention of dental caries are the most commonly published topics.
Based on keyword analysis, quality of life surveys and crown restorations have seen the most recent increase in research, likely due to the growing interest in pediatric human rights and advances in esthetic prefabricated crowns. In the JKAPD, the number of articles on SNT was particularly high, reflecting their high prevalence in East Asia [28]. Technological advancements have rapidly changed the focus of research on dental equipment. Studies on laser devices and treatments were extensively published in the early 2000s; however, interest in this field has since declined. In contrast, articles related to artificial intelligence and digital dentistry, including 3D printing and scanners, have recently been increasing [8].
From a socioeconomic perspective, the National Health Insurance Services (NHIS) expanded coverage for pit and fissure sealants from 2009 to 2013, broadening the eligible age range in Korea. In addition, the NHIS started covering composite resin restoration of dental caries in children under 12 years of age and orthodontic treatment for patients with cleft lip and palate since 2019 [29]. Interestingly, the number of beneficiaries increased significantly [30,31], however, research related to this topic decreased in the JKAPD. Furthermore, the benefits of orthodontic treatment for patients with cleft lip and palate are only applicable when performed by an orthodontic specialist. Consequently, there may be relatively less interest in this topic within the JKAPD.
Articles on treatment of malocclusion and disturbances in eruptions have been published more frequently in the JKAPD and JJPD than in the PD and EAPD. According to previous studies, the prevalence of malocclusion varies by classification; however, certain types, such as Class III malocclusion, which can cause anterior crossbite and open bite often resulting from oral habits, show a particularly high prevalence in Asia, especially among Mongolians [32,33]. These types of malocclusions often require early intervention to prevent facial growth discrepancies; therefore, a high interest in the field of pediatric dentistry is not surprising [34,35]. In addition, unlike many European countries where orthodontic treatment is covered by insurance, orthodontic treatment is not covered by the NHIS in Korea or Japan, except in a few cases. Despite the declining birth rate in these countries, increasing education and income levels have made parents more interested in seeking treatment for their children[36]. Consequently, caregivers appear to place greater emphasis on early orthodontic treatment in pediatric dental care [37,38].
More than 20 categories have been reported in previous studies [1,14,15], whereas this study included 16 subjects. This difference arises because previous studies focused on the detailed examination of tendencies within each category, whereas this study considered the integration of data for the application of statistical analyses. Statistical validation and detailed examination often exist on opposite ends of the spectrum, making it challenging to achieve both using a single set of classification criteria. If future research needs to explore the detailed trends within major classifications, this can be addressed by setting detailed classification criteria.
This study has some limitations. First, the effort to establish appropriate classification criteria by compiling various studies may have involved subjectivity in setting the distribution categories and potentially led to personal bias in the analysis. Although it would be possible to directly adopt the classification criteria from Korean textbooks on pediatric dentistry or previous studies, considering the comprehensive coverage of multiple journals, adopting new classification categories was deemed more appropriate. Since the classification criteria for pediatric dentistry may differ across countries owing to varying socioeconomic backgrounds, a more systematic classification system that can encompass all subject areas is necessary for further studies. Second, the classification of each article involved a degree of subjectivity, as the distribution was based on the final conclusions drawn by the authors rather than official judgment criteria, such as keywords. Additionally, because many studies have used more than two keywords, assigning an article to only one subject could have introduced bias. To address this, intraclass correlation coefficient values were assessed; however, involving multiple evaluators in future research may further mitigate subjectivity.
Conclusion
The distribution of research trends varies by region and over time. Although there were regional variations, the distribution of publication trends did not significantly change before or after the 21st century. Over the past 20 years, the PD has published the highest number of articles, and cariology has been the most actively researched subject. The EAPD and PD showed the highest correlation in the distribution of research topics, and the number of studies on pulp treatment was proportional to the total volume of publications. This study offers valuable insights for comparing and analyzing domestic and international research trends and highlights social and environmental changes influencing them.
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