{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T05:28:38Z","timestamp":1761888518777,"version":"build-2065373602"},"reference-count":46,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T00:00:00Z","timestamp":1761782400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>FEA of orthodontic miniscrews has predominantly assumed isotropic, homogeneous bone, neglecting directional variations in mechanical properties. This study investigated the biomechanical behavior of miniscrews under different insertion angles and loading directions using both isotropic and orthotropic mandibular bone models. The results indicated that isotropic modeling may underestimate miniscrew displacement and associated instability, whereas orthotropic material properties better reflect the true mechanical response of bone. Oblique insertion at 60\u00b0 (U60\u00b0) led to higher strain and greater variability, which may compromise osseointegration; aligning the loading direction parallel to the insertion plane is therefore recommended when oblique placement is unavoidable. Screw thread design had minimal influence on displacement, von Mises stress, or bone strain during vertical insertion. Stress and strain distributions exhibited symmetry, suggesting that analyzing partial loading directions can predict the overall biomechanical response. All predicted values remained below bone and material strength limits, confirming the mechanical safety of the current miniscrew design under a 2 N load. Implant failure is likely attributable to poor osseointegration or inflammation rather than structural limitations.<\/jats:p>","DOI":"10.3390\/ma18214963","type":"journal-article","created":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T03:33:07Z","timestamp":1761881587000},"page":"4963","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Biomechanical Influence of Placement Angle and Loading Direction of Orthodontic Miniscrews on Orthotropic Mandible"],"prefix":"10.3390","volume":"18","author":[{"given":"Yu-Ching","family":"Li","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, National Central University, Taoyuan 320317, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiun-Ren","family":"Hwang","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Central University, Taoyuan 320317, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chin-Ping","family":"Fung","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Asia Eastern University of Science and Technology, New Taipei City 220303, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5745-0403","authenticated-orcid":false,"given":"Chen-Yuan","family":"Chung","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, National Central University, Taoyuan 320317, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1080\/00016357.2018.1508742","article-title":"Anchorage effectiveness of orthodontic miniscrews compared to headgear and transpalatal arches: A systematic review and meta-analysis","volume":"77","author":"Alharbi","year":"2019","journal-title":"Acta Odontol. Scand."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1093\/ejo\/cjw041","article-title":"Effectiveness of early orthopaedic treatment with headgear: A systematic review and meta-analysis","volume":"39","author":"Papageorgiou","year":"2017","journal-title":"Eur. J. Orthod."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1016\/j.ajodo.2018.09.019","article-title":"Is there an ideal insertion angle and position for orthodontic mini-implants in the anterior palate? A CBCT study in humans","volume":"156","author":"Becker","year":"2019","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_4","first-page":"201","article-title":"Miniscrews as orthodontic anchorage: A preliminary report","volume":"13","author":"Costa","year":"1998","journal-title":"Int. J. Adult Orthodon. Orthognath. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1179\/1465312512Z.00000000037","article-title":"Deflection and stress distribution around mini-screw implants: A finite element investigation into the effect of cortical bone thickness, force magnitude and direction","volume":"39","author":"Meher","year":"2012","journal-title":"J. Orthod."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"667","DOI":"10.2319\/090112-703.1","article-title":"Effects of placement angle and direction of orthopedic force application on the stability of orthodontic miniscrews","volume":"83","author":"Lee","year":"2013","journal-title":"Angle Orthod."},{"key":"ref_7","first-page":"e117","article-title":"Success rate of infrazygomatic miniscrews considering their design and insertion techniques: A review","volume":"10","year":"2022","journal-title":"Rev. Cient. Odontol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e192","DOI":"10.1016\/j.ajodo.2022.07.013","article-title":"Miniscrews for orthodontic anchorage: Analysis of risk factors correlated with the progressive susceptibility to failure","volume":"162","author":"Xin","year":"2022","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"835","DOI":"10.11607\/jomi.4197","article-title":"Factors affecting the clinical success rate of miniscrew implants for orthodontic treatment","volume":"31","author":"Zheng","year":"2016","journal-title":"Int. J. Oral Maxillofac. Implant."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1065","DOI":"10.2319\/100707-484.1","article-title":"Insertion angle impact on primary stability of orthodontic mini-implants","volume":"78","author":"Wilmes","year":"2008","journal-title":"Angle Orthod."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1016\/j.ajodo.2016.02.020","article-title":"In-vitro impact of insertion angle on primary stability of miniscrews","volume":"150","author":"Araghbidikashani","year":"2016","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1093\/ejo\/cju006","article-title":"Finite element analysis of miniscrew placement in mandibular alveolar bone","volume":"37","author":"Perillo","year":"2015","journal-title":"Eur. J. Orthod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1016\/j.ajodo.2018.08.026","article-title":"Effects of size and insertion angle of orthodontic mini-implants on skeletal anchorage","volume":"156","author":"Tatli","year":"2019","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1016\/j.ortho.2020.03.003","article-title":"The ideal insertion angle after immediate loading in Jeil, Storm, and Thunder miniscrews: A 3D-FEM study","volume":"18","author":"Cozzani","year":"2020","journal-title":"Int. Orthod."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.jmbbm.2013.02.021","article-title":"Variability and anisotropy of mechanical behavior of cortical bone in tension and compression","volume":"21","author":"Li","year":"2013","journal-title":"J. Mech. Behav. Biomed. Mater."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1002\/ajpa.10121","article-title":"Variations in cortical material properties throughout the human dentate mandible","volume":"120","author":"Dechow","year":"2003","journal-title":"Am. J. Phys. Anthropol."},{"key":"ref_17","first-page":"87","article-title":"Creation of a three-dimensional model of the mandible and the TMJ in vivo by means of the finite element method","volume":"5","author":"Zapata","year":"2002","journal-title":"Int. J. Comput. Dent."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1038\/bonekey.2016.60","article-title":"Post-yield and failure properties of cortical bone","volume":"5","author":"Wolfram","year":"2016","journal-title":"Bonekey Rep."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"924","DOI":"10.1016\/j.medengphy.2007.12.009","article-title":"Comparison of an inhomogeneous orthotropic and isotropic material models used for FE analyses","volume":"30","author":"Baca","year":"2008","journal-title":"Med. Eng. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"935","DOI":"10.1016\/j.medengphy.2006.10.002","article-title":"Comparison of isotropic and orthotropic material property assignments on femoral finite element models under two loading conditions","volume":"29","author":"Baca","year":"2007","journal-title":"Med. Eng. Phys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1016\/j.medengphy.2010.01.004","article-title":"Some factors that affect the comparison between isotropic and orthotropic inhomogeneous finite element material models of femur","volume":"32","author":"Yang","year":"2010","journal-title":"Med. Eng. Phys."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Boggio, A., Jamilian, A., Manni, A., Gastaldi, G., Farjaminejad, R., Hasani, M., and Cozzani, M. (2025). The effect of a Manni telescopic Herbst appliance with four miniscrews (STM4) on the treatment of a Class II Division I malocclusion: A 3D finite element study. Oral, 5.","DOI":"10.3390\/oral5020027"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Nazeri, A., Castillo, J.A., and Ghaffari-Rafi, A. (2025). Impact of molar distalization with clear aligners on periodontal ligament stress and root resorption risk: A systematic review of 3D finite element analysis studies. Dent. J., 13.","DOI":"10.3390\/dj13020065"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Hwang, J.B., and Mo, S.S. (2023). Finite element analysis of maxillary teeth movement with time during en masse retraction using orthodontic mini-screw. Appl. Sci., 13.","DOI":"10.3390\/app13063579"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Kim, J.H., Hyeok, J.J., Woo, J.H., and Kim, S.M. (2025). Correlation analysis of suture anchor pull-out strength with cortical bone thickness and cancellous bone density on a finite element model. Bioengineering, 12.","DOI":"10.3390\/bioengineering12080863"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Pimentel-Mendoza, A.B., Rico-P\u00e9rez, L., Rosel-Solis, M.J., Villarreal-G\u00f3mez, L.J., Vega, Y., and D\u00e1valos-Ram\u00edrez, J.O. (2021). Application of inverse neural networks for optimal pretension of absorbable mini plate and screw system. Appl. Sci., 11.","DOI":"10.3390\/app11031350"},{"key":"ref_27","first-page":"3028","article-title":"Histomorphometric evaluation of cortical bone surrounding miniscrew: Why is the insertion torque critical for primary stability?","volume":"29","author":"Ohtani","year":"2018","journal-title":"Biomed. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"721","DOI":"10.1016\/j.ajodo.2006.02.026","article-title":"Quantitative evaluation of cortical bone thickness with computed tomographic scanning for orthodontic implants","volume":"129","author":"Deguchi","year":"2006","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_29","first-page":"109","article-title":"Assessment of palatal bone thickness in adults with cone beam computerized tomography","volume":"23","author":"Gracco","year":"2007","journal-title":"Aust. Orthod. J."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"651","DOI":"10.1016\/j.ajodo.2016.03.026","article-title":"Determination of soft tissue thickness at orthodontic miniscrew placement sites using ultrasonography for customizing screw selection","volume":"150","author":"Parmar","year":"2016","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"S1478","DOI":"10.4103\/jpbs.jpbs_17_25","article-title":"In Vitro Evaluation of Stress Distribution around Implants with Different Designs","volume":"17","author":"Javiya","year":"2025","journal-title":"J. Pharm. Bioallied Sci."},{"key":"ref_32","unstructured":"ASM International (2012). Medical Applications of Stainless Steels, ASM International."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1093\/ejo\/cjm078","article-title":"Osseointegration of miniscrews: A histomorphometric evaluation","volume":"29","author":"Wehrbein","year":"2007","journal-title":"Eur. J. Orthod."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"189","DOI":"10.4041\/kjod.2016.46.4.189","article-title":"Stress distributions in peri-miniscrew areas from cylindrical and tapered miniscrews inserted at different angles","volume":"46","author":"Choi","year":"2016","journal-title":"Korean J. Orthod."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Tokuyama-Toda, R., Umeki, H., Ide, S., Kobayashi, F., Tooyama, S., Umehara, M., Tadokoro, S., Tomonari, H., and Satomura, K. (2023). A new implantation method for orthodontic anchor screws: Basic research for clinical applications. Biomedicines, 11.","DOI":"10.3390\/biomedicines11030665"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"483","DOI":"10.11113\/mjfas.v13n4-2.817","article-title":"Different material properties of cancellous bone influence analysis of glenoid component loosening: A finite element study","volume":"13","author":"Harun","year":"2017","journal-title":"Malays. J. Fundam. Appl. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1007\/s40430-018-1409-9","article-title":"A comparative finite element simulation of stress in dental implant\u2013bone interface using isotropic and orthotropic material models in three mastication cycles","volume":"40","author":"Taheri","year":"2018","journal-title":"J. Braz. Soc. Mech. Sci. Eng."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"276","DOI":"10.4028\/www.scientific.net\/MSF.872.276","article-title":"Study on the performance of orthodontic self-drilling correction screw of Ti6Al4V and stainless 316L","volume":"872","author":"Do","year":"2016","journal-title":"Mater. Sci. Forum"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1186\/s13005-017-0143-3","article-title":"Comparative evaluation of insertion torque and mechanical stability for self-tapping and self-drilling orthodontic miniscrews: An in vitro study","volume":"13","author":"Tepedino","year":"2017","journal-title":"Head Face Med."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1265","DOI":"10.1016\/j.bone.2006.12.065","article-title":"Strain redistribution and cracking behavior of human bone during bending","volume":"40","author":"Ebacher","year":"2007","journal-title":"Bone"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/j.ajodo.2011.07.022","article-title":"Three-dimensional finite element analysis of strength, stability, and stress distribution in orthodontic anchorage: A conical, self-drilling miniscrew implant system","volume":"141","author":"Singh","year":"2012","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Teekavanich, C., Uezono, M., Takakuda, K., Ogasawara, T., Techalertpaisarn, P., and Moriyama, K. (2021). Evaluation of cortical bone microdamage and primary stability of orthodontic miniscrew using a human bone analogue. Materials, 14.","DOI":"10.3390\/ma14081825"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"344","DOI":"10.11607\/jomi.5061","article-title":"Stress distribution in obliquely inserted orthodontic miniscrews evaluated by three-dimensional finite-element analysis","volume":"32","author":"Kuroda","year":"2017","journal-title":"Int. J. Oral Maxillofac. Implant."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.ijom.2008.09.006","article-title":"The effect of cortical bone thickness on the stability of orthodontic mini-implants and on the stress distribution in surrounding bone","volume":"38","author":"Motoyoshi","year":"2009","journal-title":"Int. J. Oral Maxillofac. Surg."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.jcms.2018.10.020","article-title":"Mechanical impairment on alveolar bone graft: A literature review","volume":"47","author":"Dissaux","year":"2019","journal-title":"J. Craniomaxillofac. Surg."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"875","DOI":"10.2319\/111011-696.1","article-title":"Factors affecting stresses in cortical bone around miniscrew implants: A three-dimensional finite element study","volume":"82","author":"Duaibis","year":"2012","journal-title":"Angle Orthod."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/21\/4963\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T03:44:08Z","timestamp":1761882248000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/21\/4963"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,30]]},"references-count":46,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["ma18214963"],"URL":"https:\/\/doi.org\/10.3390\/ma18214963","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,30]]}}}