Abstract

Objectives: This study aimed to map the scientific landscape of bone augmentation within oral and maxillofacial surgery using bibliometric methods, identify publication and citation trends and highlight the most influential contributions shaping current clinical practice.

Methods: Relevant articles were retrieved from the Web of Science Core Collection using a tailored search strategy. Bibliometric analyses were performed with the Bibliometrix R-package to assess publication trends, author collaboration networks, keyword co-occurrences and thematic structures. Co-citation analysis was conducted to explore the evolving intellectual framework, with emphasis on clinical relevance.

Results: Publications on bone augmentation have steadily increased since the mid-2000s, with a notable citation peak in 2006. Clinical Oral Implants Research and the International Journal of Oral and Maxillofacial Implants were identified as leading publication platforms. The 1997 study by Zitzmann NU received 114 local citations, achieving an LC/GC ratio of 26.21%. Key thematic trends revealed a balance between basic research and applied surgical innovations.

Conclusion: Bone augmentation remains a dynamic and growing area within oral and maxillofacial surgery. These bibliometric insights can guide future collaborations, inform research priorities and support the integration of evidence into clinical decision making for improved patient outcomes.

Keywords: Bone Augmentation; Bibliometrix R-Package; Key Thematic Trends

Introduction

Alveolar bone loss is a common and significant clinical problem in dentistry. Although most frequently associated with periodontitis, it can also result from tooth extraction, trauma and other local factors, all of which contribute to dimensional changes in the alveolar ridge [1,2]. These alterations adversely affect tooth stability, function and esthetics and often necessitate the restoration of bone volume prior to dental implant placement [3].  To address this challenge, various bone augmentation techniques have been developed, including vertical, horizontal or combined approaches depending on the type of defect [4]. These procedures typically require the integration of autologous, allogeneic, xenogeneic or synthetic graft materials, along with barrier membranes and bioactive agents such as growth factors [5-7].

Although augmentation techniques and materials have been extensively studied, the field remains dynamic and continuously evolving. This ongoing development makes it increasingly challenging for researchers to keep pace with the expanding body of literature. Therefore, a comprehensive mapping of the scientific landscape and research trends in this area is of significant importance.

Bibliometric analysis has emerged as a valuable tool for assessing scientific output across various elements such as articles, authors, keywords, journals, institutions and countries within a given research field. It enables the examination of how a field has evolved over time based on the relationships and interactions among these components [8,9]. Such analyses allow for a comprehensive and systematic understanding of a field’s current structure, the identification of research clusters, the detection of emerging trends and the mapping of core concepts along with their interconnections [10]. In this context, bibliometric approaches have been widely applied across various subfields of medicine and dentistry, proving to be an effective method for exploring the dynamics of domain-specific scientific production [11,12].

This study aims to conduct a bibliometric analysis of scientific publications on bone augmentation in dentistry published in the Web of Science (WoS) database between 1980 and 2025. By comprehensively evaluating publication trends, leading researchers and institutions, citation patterns and thematic developments, the study seeks to map the historical evolution of scientific output in the field of bone augmentation. The findings are intended to provide researchers working in this area with an integrated perspective for assessing the current knowledge structure, identifying future research opportunities and developing strategic directions.

Material and Methods

This bibliometric study aimed to provide a comprehensive overview of research on bone augmentation procedures in dentistry. The search strategy was designed to capture a wide range of augmentation techniques in order to map the scientific landscape as broadly as possible. Including different augmentation approaches in a single dataset enabled the identification of shared research themes, overlapping biomaterials and methodological advances. Other regenerative indications, such as socket preservation and peri-implantitis defect grafting, were excluded because they represent distinct clinical scenarios with different objectives and evaluation criteria. The search strategy and methodological workflow are summarized in Supplementary Fig. 1. PRISMA-S (Preferred Reporting Items for Systematic Reviews and Meta-Analyses – Search extension) guidelines, which are internationally recognized for enhancing transparency and reproducibility in systematic reviews [11]. A completed PRISMA-S checklist is provided in Supplementary Fig. 1. The search parameters are summarized in Supplementary Table 1, detailing database selection, search date, full query, applied filters and number of retrieved records after each screening step. Since all data used in this study are publicly available, ethical approval was not required.

In this study, the Web of Science (WoS) database one of the most commonly used platforms for bibliometric analysis and literature searches was utilized. Different databases vary significantly in terms of journal coverage. WoS is among the most preferred academic sources due to its reliability and comprehensive indexing of high-quality scientific publications [12].

The data search was conducted on May 25, 2025, by Ş.Ç.B using the Web of Science (WoS) database. In the subsequent stage, the retrieved data were screened and filtered. A comprehensive search was performed in WoS using the following query: (“Bone Grafting Maxillary” OR “Bone Augmentation” OR “Alveolar Bone Grafting” OR “Alveolar Ridge Augmentation” OR “Bone Transplantation Maxillary” OR “Bone Regeneration” OR “Dental Bone Graft” OR “Block Graft” OR “Bone Graft Substitute” OR “Bone Substitute” OR “Bone Substitutes” OR “Bone Scaffold” OR “Bone Graft” OR “Bone Grafts” OR “Guided Bone Regeneration” OR “GBR” OR “Maxillary Sinus Lift” OR “Alveolar Bone” OR “Alveolar Bone Preservation” OR “Maxillofacial Bone Augmentation” OR “Hard Tissue Augmentation” OR “Vertical Ridge Augmentation” OR “Horizontal Ridge Augmentation” OR “Maxillary Bone Augmentation” OR “Mandibular Bone Augmentation” OR “Bone Augmentation Techniques” OR “Ridge Split” OR “Ridge Splitting” OR “Bone Splitting” OR “Ridge Expansion” OR “Autogenous Block Graft” OR “Bone Graft Materials” OR “Augmentation Techniques” OR “Khoury Bone Block Technique” OR “Sausage Technique” OR “Urban Technique” OR “Shell Technique” OR “Split-Crest Technique” OR “Bone Volume” OR “Split Bone Block Technique” OR “Tenting Screw Technique” OR “Titanium Mesh” OR “3D Mesh” OR “Collagen Membrane” OR “Narrow Ridge” OR “Sandwich Technique” OR “Sandwich Osteotomy” OR “Segmental Osteotomy” OR “Interpositional Graft” OR “Autograft” OR “Allograft” OR “Xenograft” OR “Resorbable Membrane” OR “Non-Resorbable Membrane” OR “PTFE Membrane” OR “Barrier Membrane” OR “Titanium-Reinforced Membrane”). This initial search yielded 62,502 records. After limiting the document types to “Article OR Review Article,” 40,658 records remained. When the WoS indexes “SCI-EXPANDED, ESCI, CPCI-S” were selected, the number was reduced to 40,410. Further filtering by the subject category “Dentistry Oral Surgery Medicine” yielded 2,884 records. Restricting the language to English resulted in 2,819 publications. After excluding two retracted articles (document types: retracted publication), a total of 2,817 publications remained. Since new records are continually added to the database, publications from the year 2025 were excluded to ensure data stability and the final analysis was conducted on 2,722 publications.

The Bibliometrix software was used to perform the analysis of the retrieved data. Bibliometrix is a recent open-source R-based tool developed for conducting science mapping and bibliometric analysis [13].

In our study, a total of 2,722 articles were analyzed under four main sections: publication performance, keyword analysis, co-citation analysis and thematic analysis. During the keyword analysis, similar or synonymous terms were merged under a single keyword to prevent inflation of the total keyword count due to repetitive terms.

Performance Analysis

This section evaluated key bibliometric indicators, including the h-, m- and g-indices, Total Citations (TC), Publication Year (PY) and Number of Publications (NP). The h-index measures research impact; the m-index adjusts it by career length and the g-index emphasizes highly cited works [14-17].

Journal clustering based on Bradford’s Law revealed that most literature is concentrated in a few core journals, while the rest is spread across many less frequent sources, following a structured distribution pattern [18].

A three-field graph was also used to visualize the relationships among authors, institutions and keywords, offering an integrated view of the bibliometric landscape [13].

Keyword Analysis

Keywords selected by authors are crucial for identifying research trends, as they reflect the core content of publications. Word cloud analysis was used to highlight the most frequently occurring terms, with word size proportional to frequency, thus revealing dominant and overlapping research themes over time [8,13].

Co-Citation Analysis

This method identifies the most frequently cited publications and their interconnections, offering insights into the intellectual foundations and developmental trajectory of the field [19].

Thematic Analysis

Thematic analysis was conducted to explore dominant topics and their evolution. Using thematic mapping, research themes were visualized across four quadrants in a strategic diagram:

Motor Themes: High centrality and density; core, well-developed topics.

Niche Themes: High density, low centrality; specialized but isolated.

Emerging/Declining Themes: Low density and centrality; either nascent or fading.

Basic Themes: Low density, high centrality; essential but underexplored.

This framework provides a static yet informative view of research structure and dynamics [20].

Results

Performance Analysis

Statistical information regarding bibliometric data on bone augmentation between 1980 and 2024 is presented in Table 1. A total of 2,722 publications were analyzed, originating from 143 different sources. The average Annual Growth Rate (AGR) was 9.78%, indicating an accelerating trend in scholarly output. The AGR was calculated using the exponential growth model commonly applied in bibliometric studies. Growth rate = [(number of documents in the last year ÷ number of documents in the first year)1/ (last year − first year) − 1] × 100. Exponential growth rate (r) = ln W2 – ln W1÷T2 − T1 where: ln W2 = Natural log of the initial number of articles, ln W1 = Natural log of the final number of articles after a specific period, T2 − T1 = The unit difference between the initial time and the final time. The annual average growth rate was 9.78%, reflecting increasing academic interest in the field. The mean age of the publications was 11.5 years, with an average of 30.29 citations per article. Overall, 42,242 references were cited.

A total of 8,776 authors contributed to the literature, with only 84 single author articles published. The average number of co-authors per article was 5.09 and international collaboration accounted for 26.63% of the publications. Regarding document types, 2,468 were research articles, 201 were reviews, 40 were conference proceedings and 13 were early access articles.

In total, 3,152 Keywords Plus and 3,436 author keywords were used, demonstrating the terminological diversity within the literature.

The annual publication trends presented in Figure 1 reveal a notable increase starting from the mid-2000s, reaching a peak of 182 publications in 2024. The year 2006 recorded the highest average citations per article, with 5.2 citations. However, despite the recent surge in publication numbers particularly between 2022 and 2024 a decline in citation rates has been observed. This trend likely reflects that newer publications have not yet had sufficient time to accumulate citations. 

Supplementary Table 2 presents the top 20 most influential authors in the field of Bone Augmentation ranked by their h-index. Leading the list is Wang HL, who has published 56 articles since 2006, accumulating a total of 2,206 citations, with an h-index of 27 and a g-index of 49. He is followed by Jung R.E., who has published 45 articles since 2003 and received a total of 2,720 citations, with an h-index of 26 and a g-index of 52.

Supplementary Table 3 lists the top 20 journals in Bone Augmentation ranked by h-index, representing 66.05% of all publications (1,798 of 2,722). Key metrics include h-index, g-index, total citations, publication count, citations per article and starting year.

Clinical Oral Implants Research leads with 306 articles and 14,787 citations, averaging 48.3 citations per article. The International Journal of Oral and Maxillofacial Implants follows, with 178 articles, an h-index of 43 and an average of 40.8 citations per article.

Most publications appear in journals specializing in periodontology, oral implantology and maxillofacial surgery. Some journals with fewer articles still show high citation impact, highlighting the interdisciplinary and scientifically rich nature of the field.

Citation analysis identified the 20 most locally cited publications in bone augmentation, as shown in Supplementary Table 4. Key metrics include publication year, local and global citation counts, average citations per year and the ratio of local to global citations.

The most cited paper by Zitzmann NU received 114 local citations and 435 global citations, with a local-to-global citation ratio of 26.21%, indicating significant impact both locally and internationally. Jensen SS’s study followed closely with 108 local citations and the highest average local citations per year (6.75). Despite being more recent, Benic GI’s publication also showed strong influence, with a 29.31% local to global citation ratio.

Funding Analysis

Most frequent funding agencies in bone augmentation publications (1980-2024) show in Supplementary Table 5. Funding information was available for 914 of the 2,722 publications.  According to the WoS “Funding Agency” field, the most frequent sponsors were:

• National Natural Science Foundation of China (NSFC)
• National Institutes of Health (NIH)
• European Commission (Horizon 2020)

These agencies have played a central role in shaping the research agenda in bone augmentation. Funding analysis offers important insights into the structural and geographic drivers of research activity, highlighting that bibliometric assessments should integrate funding patterns alongside citation-based indicators.

Word Analysis

Supplementary Fig. 2 presents a word cloud illustrating the 50 most frequently used keywords in the bone augmentation literature, with the size of each term reflecting its frequency within the dataset. The most commonly used keyword in this field is “Bone Regeneration,” appearing 1,179 times. It is followed by “Dental Implant” (455), “Bone Augmentation” (232), “Alveolar Ridge Augmentation” (149) and “Alveolar Bone Grafting” (142).

Fig. 2 illustrates the changing trends in keyword usage over the years, highlighting emerging focal points within the field. According to the findings presented in Fig. 2, keywords such as “Bone Regeneration,” “Dental Implant,” “Bone Graft,” “Biomaterials,” and “Bone Substitutes” have been frequently used since the early 2000s and have maintained their significance to the present day. After 2010, terms related to technical and biological approaches, including “Cone Beam Computed Tomography,” “Tissue Engineering,” “Platelet-Rich Plasma,” and “Collagen,” became more prominent. From 2015 onwards, the use of multidisciplinary terms such as “Cleft Lip,” “Meta-Analysis,” “Inflammation,” and “Hyaluronic Acid” has notably increased.

Co-Citation Network Analysis

Fig. 3 presents a Paper Co-citation Network analysis of bone augmentation literature, examining the co-citation relationships among publications. The analysis applied the Walktrap algorithm and included the top 25 most cited papers. As shown in Fig. 3, the co-citation network is divided into four clusters represented by red, blue, green and purple nodes.

The red cluster centers around seminal works by authors such as Dahlin C, Buser D and Dahlin C, which are frequently co-cited together. The blue cluster highlights studies by Araújo MG, Simion M and Zitzmann NU though with lower centrality and citation density compared to the red cluster. Smaller clusters are also observed in green and purple, representing other thematic groups within the literature.

Authors Co-Citation Network analysis revealed two main clusters in bone augmentation research, as illustrated in Fig.3. Buser D, emerged as the most central author, frequently cited both individually and in conjunction with Simion M, Dahlin C, Zitzmann NU and Becker W, who represent foundational contributors within the red cluster. In contrast, the blue cluster included notable figures such as Chiapasco M, Hämmerle CHF, Araújo MG, Jensen SS and Donos N.

Fig. 3 illustrates the Sources Co-citation Network analysis of journals publishing bone augmentation research. Node size represents the number of co-citations a journal receives, while edge thickness indicates the intensity of co-citation links between journals.

The blue cluster mainly includes journals focused on dentistry, particularly periodontology and dental implantology. Leading journals in this cluster with the largest nodes are Clinical Oral Implants Research, Journal of Periodontology, International Journal of Oral and Maxillofacial Implants and Journal of Clinical Periodontology.

The red cluster comprises journals primarily centered on oral and maxillofacial surgery and biomaterials research, with prominent titles including Journal of Oral and Maxillofacial Surgery, International Journal of Oral and Maxillofacial Surgery, Plastic and Reconstructive Surgery, Biomaterials and Journal of Craniomaxillofacial Surgery.

The smaller green cluster represents a distinct group, notably featuring the Cleft Palate Craniofacial Journal.

Fig. 4 shows the historical citation network of bone augmentation literature created using Bibliometrix. It visualizes citation links among the top 19 locally cited papers over time. The earliest work by Dahlin C, connects to subsequent studies by Hämmerle CHF and Retzepi M. Later publications by Benic GI, Rakhmatia YD and others form the more recent part of the network. Rocchietta I, is noted for its extensive connections within the network.

Thematic Analysis

Fig. 5 shows a thematic map of bone augmentation research based on 500 frequently used author keywords clustered by the Louvain algorithm. Themes are divided into four groups by centrality and density:

Motor Themes: Well-developed and central topics like “Bone Regeneration” and “Biomaterials”.

Niche Themes: Specialized but less connected areas such as “Alveolar Bone Grafting” and “Peri-Implantitis”.

Emerging or Declining Themes: Peripheral and less developed topics like “Platelet-Rich Fibrin” and “Socket Preservation”.

Basic Themes: Fundamental but underexplored subjects including “Dental Implant,” “Bone Augmentation,” and “Tissue Engineering”.