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    Experimental comparison of fixation methods with different plates in sagittal split ramus osteotomy
    (Elsevier Singapore Pte Ltd, 2026) Ustundag, Irfan; Sancar, Bahadir
    Background: This is an in vitro experimental study designed to evaluate fixation methods used after sagittal split ramus osteotomy (SSRO), particularly in cases where significant mandibular advancement is necessary. In clinical settings, postoperative relapse is one of the major challenges following SSRO, especially when the mandible is advanced more than a few millimeters. To minimize relapse, optimal stabilization of the mandibular segments is essential. Therefore, the objective of this study is to compare the biomechanical stability of three different fixation systems: single miniplate, double miniplates, and single reconstruction plate, under progressive loading conditions. Methods: A total of 45 fresh sheep hemimandibles underwent SSRO, and each was advanced 7 mm to simulate a clinically significant advancement. The specimens were randomly divided into three equal groups (n = 15). Group 1 was fixed with one miniplate and four screws; Group 2 with two miniplates and eight screws; and Group 3 with one reconstruction plate and four screws. Vertical forces ranging from 10 to 200 Newton (N) were applied in increments of 10 N. Segment displacement was measured for each force level. Data were analyzed using the Shapiro-Wilk test for normality, Kruskal-Wallis test for group comparisons, and Bonferroni correction for pairwise significance (p < 0.05). Results: The double miniplate and reconstruction plate groups showed significantly lower displacement compared to the single miniplate group. There was no significant difference between double miniplates and reconstruction plates. Conclusions: For cases requiring major mandibular advancement, reconstruction plates or double miniplates are recommended for enhanced mechanical stability and relapse prevention.(c) 2025 Asian Surgical Association and Taiwan Society of Coloproctology. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/).
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    Investigation of the effect of impacted third molar position and orientation on bad split fractures in sagittal split ramus osteotomy using finite element analysis
    (Bmc, 2025) Ustundag, Irfan; Mecu, Erkan; Cetiner, Yunus; Simsek, Mehmet Sait
    Background This study aims to evaluate the impact of different angular orientations and buccolingual positions of impacted third molars on the incidence of bad splits during sagittal split ramus osteotomy using finite element analysis. Materials and methods A total of 12 mandibular models were constructed, each representing a unique combination of third molar orientations (vertical, distoangular, horizontal, mesioangular) and positions (buccal, lingual, central). A force of 20 N was applied from the osteotomy line toward the proximal and distal segments to simulate the working principle of the Smith Spreader instrument. Results The maximum principal stress followed the order: vertical > distoangular > horizontal > mesioangular. In terms of positional stress distribution, the buccal position generated the highest stress, followed by lingual and central positions. Similar trends were observed across all stress criteria evaluated. Conclusion The orientation and position of impacted third molars have a direct effect on the risk of bad splits during SSRO. Mesioangular and centrally positioned teeth were associated with lower stress levels, indicating lower risk, while vertically oriented and buccally or lingually positioned molars showed significantly higher stress concentrations. Thus, extraction of high-risk impacted third molars prior to surgery is recommended to reduce the likelihood of complications.
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    Temporomandibular joint arthrocentesis: global research trends in a comprehensive bibliometric analysis (1989-2025)
    (Taylor & Francis Ltd, 2026) Derin, Ahmet Faruk; Simsek, Mehmet Sait; Ustundag, Irfan
    ObjectiveOver the past three decades, temporomandibular joint (TMJ) arthrocentesis has evolved from a mechanical lavage procedure into a sophisticated treatment standard incorporating principles of biological modulation and regenerative medicine. The aim of this study is to analyze the global TMJ arthrocentesis literature between 1989 and 2025 using bibliometric methods, thereby objectively mapping the procedure's technical evolution, clinical paradigm shifts (the transition from Axis I to Axis II), and the migration of research focus from surgical technique to biopsychosocial management.Materials and MethodsData were retrieved from the Web of Science Core Collection (WoSCC) database on January 13 2026. A total of 792 original articles and reviews, identified through a comprehensive search strategy, were analyzed using VOSviewer and R-Bibliometrix software regarding annual growth rate, citation networks, conceptual structure, and global collaboration dynamics.ResultsThe literature was found to be expanding with an annual growth rate of 12.1%, peaking in 2024 in terms of both publication count (n = 74) and citations (n = 1952). While the USA (n = 111) remains the most productive country, Turkey (n = 107) ranks second, demonstrating its strong clinical activity in the field. In citation networks, Nitzan's anchored disc theory (n = 314 citations) maintains its central position; however, the rise of Schiffman's DC/TMD criteria (n = 125 citations) and Manfredini's psychosocial studies indicates that success is now contingent more upon patient phenotype than physical parameters. Furthermore, the concepts of ultrasound guidance and regenerative agents (PRP, HA) have dominated the literature in recent years.ConclusionThe TMJ arthrocentesis literature is undergoing a dynamic transformation characterized by surgical minimization and technological integration. Research trends corroborate that the concept of mechanical success has yielded to a holistic treatment model constituted by accurate patient selection (Axis II), imaging guidance, and biological regeneration.