Biomechanical Evaluation of Orthodontic Miniscrews: How Insertion Angle and Number of Insertions Impact Pull-Out Strength
DOI:
https://doi.org/10.30659/odj.13.2.162-171Keywords:
Biomechanical phenomena, bone screw, materials testing, polyurethanesAbstract
Background: This study aimed to analyze the effects of insertion angle and number of insertions on miniscrew pull-out strength in polyurethane bone blocks.
Method: In this experimental study, 30 miniscrews (Mico One; 2 mm diameter and 10 mm length) were inserted into Sawbones polyurethane blocks consisting of a 2 mm cortical layer (40 pcf) and an 18 mm trabecular layer (20 pcf). Samples were divided into six groups based on insertion angle (45°, 70°, and 90°) and number of insertions (single vs. repeated). Pull-out strength was measured using a Universal Testing Machine (UTM). Data were analyzed using two-way ANOVA followed by Tukey's HSD post hoc test, with significance set at p<0,05.
Result: In the single-insertion group, the insertion angle significantly affected pull-out strength (p<0,05). The 70° angle yielded the highest mean pull-out strength (339,98±20,76N), which was significantly higher than that of the 90° angle (299,93±20,45N; p<0,05). In the repeated-insertion group, the insertion angle did not significantly affect pull-out strength (p>0,05). Although the repeated-insertion group showed a lower mean pull-out strength (307,88±24,78 N) than the single-insertion group (318,34±25,21N), the difference was not significant (p>0,05).
Conclusion: Insertion angle significantly influences pull-out strength in single-insertion miniscrews, with 70° providing the highest strength. The number of insertions (single vs. repeated) does not significantly affect pull-out strength. These findings have implications for clinical anchorage strategies and experimental protocols using polyurethane bone analogs.References
Ummat A, Shetty S, Desai A, Nambiar S, Natarajan S. Comparative assessment of the stability of buccal shelf mini-screws with and without pre-drilling- a split-mouth, randomized controlled trial. Clin Oral Investig. 2024;28(10):567. https://doi.org/10.1007/s00784-024-05925-7
Antoszewska-Smith J, Sarul M, Łyczek J, Konopka T, Kawala B. Effectiveness of orthodontic miniscrew implants in anchorage reinforcement during en-masse retraction: A systematic review and meta-analysis. Am J Orthod Dentofac Orthop. 2017;151(3):440–55. https://doi.org/10.1016/j.ajodo.2016.08.029
Bourassa C, Hosein YK, Pollmann SI, Galil K, Bohay RN, Holdsworth DW, et al. In-vitro comparison of different palatal sites for orthodontic miniscrew insertion: Effect of bone quality and quantity on primary stability. Am J Orthod Dentofac Orthop. 2018;154(6):809–19. https://doi.org/10.1016/j.ajodo.2018.02.010
Jariyapongpaiboon P, ;Chartpitak J. Effect of Angular Insertion of Orthodontic Miniscrews on Primary Stability. Taiwan J Orthod. 2020;32(3). http://doi.org/10.38209/2708-2636.1032
Lakshmikantha HT, Ravichandran NK, Jeon M, Kim J, Park HS. 3-Dimensional characterization of cortical bone microdamage following placement of orthodontic microimplants using Optical Coherence Tomography. Sci Rep. 2019;9(1):3242. http://doi.org/10.1038/s41598-019-39670-9
Tepedino M, Masedu F, Chimenti C. Comparative evaluation of insertion torque and mechanical stability for self-tapping and self-drilling orthodontic miniscrews – an in vitro study. Head Face Med. 2017;13(1):10. http://doi.org/10.1186/s13005-017-0143-3
Abidin SZ, Dasor MM. Methods for Assessing Orthodontic Mini Implant Stability. J Multidiscip Dent Res. 2024;10(2):68–73. https://doi.org/10.38138/JMDR/v10i2.18
Nenen F, Garnica N, Rojas V, Oyonarte R. Comparison of the primary stability of orthodontic miniscrews after repeated insertion cycles: Angle Orthod. 2021;91(3):336–42. https://doi.org/10.2319/050120-375.1
Araghbidikashani M, Golshah A, Nikkerdar N, Rezaei M. In-vitro impact of insertion angle on primary stability of miniscrews. 2016;150(3):436–443. http://dx.doi.org/10.1016/j.ajodo.2016.02.020
Alkadhimi A, Al-Awadhi EA. Miniscrews for orthodontic anchorage: a review of available systems. J Orthod. 2018;45(2):102–14. https://doi.org/10.1080/14653125.2018.1443873
Möhlhenrich SC, Heussen N, Modabber A, Bock A, Hölzle F, Wilmes B, et al. Influence of bone density, screw size and surgical procedure on orthodontic mini-implant placement – part B: implant stability. Int J Oral Maxillofac Surg. 2021;50(4):565–72. https://doi.org/10.1016/j.ijom.2020.07.003
Wilmes B, Su Y yu, Drescher D. Insertion Angle Impact on Primary Stability of Orthodontic Mini-Implants. 2008;78(6):1065–70. http://dx.doi.org/10.2319/100707-484.1
Alharbi F, Almuzian M, Bearn D. Miniscrews failure rate in orthodontics: systematic review and meta-analysis. Eur J Orthod [Internet]. 2018;40(5):519–30. https://doi.org/10.1093/ejo/cjx093
Hong SB, Kusnoto B, Kim EJ, BeGole EA, Hwang HS, Lim HJ. Prognostic factors associated with the success rates of posterior orthodontic miniscrew implants: A subgroup meta-analysis. Korean J Orthod. 2016;46(2):111. http://synapse.koreamed.org/DOIx.php?id=10.4041/kjod.2016.46.2.111
Baumgaertel S, Jones CL, Unal M. Miniscrew biomechanics: Guidelines for the use of rigid indirect anchorage mechanics. Am J Orthod Dentofac Orthop. 2017;152(3):413–9. http://dx.doi.org/10.1016/j.ajodo.2017.04.020
Parinyachaiphun S, Petdachai S, Chuenchompoonut V. Considerations for placement of mandibular buccal shelf orthodontic anchoring screw in Class III hyperdivergent and normodivergent subjects – A cone beam computed tomography study. Orthod Waves. 2018;77(1):44–56. http://dx.doi.org/10.1016/j.odw.2018.01.001
Xin Y, Wu Y, Chen C, Wang C, Zhao L. Miniscrews for orthodontic anchorage: analysis of risk factors correlated with the progressive susceptibility to failure. Am J Orthod Dentofac Orthop. 2022;162(4):e192–202. https://doi.org/10.1016/j.ajodo.2022.07.013
Popa A, Dehelean C, Calniceanu H, Watz C, Brad S, Sinescu C, et al. materials A Custom-Made Orthodontic Mini-Implant — E ff ect of Insertion Angle and Cortical Bone Thickness on Stress Distribution with a Complex In Vitro and In Vivo Biosafety Profile. 2020;13(4789). https://doi.org/10.3390/ma13214789
Nguyen M V., Codrington J, Fletcher L, Dreyer CW, Sampson WJ. The influence of miniscrew insertion torque. Eur J Orthod. 2018;40(1):37–44. https://doi.org/10.1093/ejo/cjx026
Wang L, Oyonarte R, Carmona R, Bidart C, Battaglia G. Characteristics of the Buccal Shelf for the installation of miniscrews in Chilean individuals aged 15-45 years: a descriptive study. J Oral Res. 2024;13(1):222–33. https://doi.org/10.17126/joralres.2024.020
Chhatwani S, Kouji-Diehl O, Kniha K, Modabber A, Hölzle F, Szalma J, et al. Significance of bone morphology and quality on the primary stability of orthodontic mini-implants: in vitro comparison between human bone substitute and artificial bone. J Orofac Orthop / Fortschritte der Kieferorthopädie. 2023;84(6):362–72. https://doi.org/10.1007/s00056-022-00385-8
Aarash V, Abdollahi F, Ghorbanipour R, Mehdi M, Sistani N, Bijani A. Effect of insertion angles and reusing procedure on mini-screws’ mechanical properties. J Res Med Dent Sci. 2017;5(3):63–8. https://www.researchgate.net/profile/Ali-Bijani/publication/320279920_Effect_of_insertion_angles_and_reusing_procedure_on_mini-screws’_mechanical_properties/links/59dae2560f7e9b12b36d910b/Effect-of-insertion-angles-and-reusing-procedure-on-mini-screws-mec
Meira TM, Tanaka OM, Ronsani MM, Maruo IT, Guariza-filho O, Camargo ES, et al. Insertion torque , pull-out strength and cortical bone thickness in contact with orthodontic mini-implants at different insertion angles. 2013;35:766–71. https://doi.org/10.1093/ejo/cjs095
Mathews MC, PU B, Lakshmanan L, Joseph V. A Review on Mandibular Buccal Shelf Miniscrew. Cross Curr Int J Med Biosci. 2021;3(4):46–7. https://doi.org/10.36344/ccijmb.2021.v03i04.002
Xu Z, Wu Y, Zhao L, Zhou Y, Wei X, Tang N, et al. Effect of placement angle on the stability of loaded titanium microscrews in beagle jaws. 2013;83(4). https://doi.org/10.2319/081612-660.1
Kim GT, Jin J, Mangal U, Lee KJ, Kim KM, Choi SH, et al. Primary Stability of Orthodontic Titanium Miniscrews due to Cortical Bone Density and Re-Insertion. Materials (Basel). 2020;13(19):4433. https://doi.org/10.3390/ma13194433
Hergel CA, Acar YB, Ateş M, Küçükkeleş N. In-vitro evaluation of the effects of insertion and sterilization procedures on the mechanical and surface characteristics of mini screws. Eur Oral Res. 2019;53(1):25–31. http://doi.org/10.26650/eor.20197993
Downloads
Published
Issue
Section
License
Authors who publish with this journal agree to the following terms:
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
This work is licensed under a Creative Commons Attribution 4.0 International License.
