{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T06:41:47Z","timestamp":1763534507241,"version":"3.45.0"},"reference-count":47,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T00:00:00Z","timestamp":1763510400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Bioeng. Biotechnol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>This study aimed to evaluate the biomechanical effects of varying sagittal root position (SRP), root length (RL), and cortical bone thickness (CBT) on tooth movement and stress distribution during clear aligner therapy (CAT) in extraction cases, using finite element analysis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Three-dimensional finite element models, including the maxillary alveolar bone, periodontal ligament (PDL), dentition, and clear aligner, were constructed. Groups with varying SRP (labial, middle, and palatal), RL (long, normal, short) and CBT (1\u00a0mm, 2\u00a0mm) were established. Tooth movement and stress distribution were analyzed for each group after 0.2\u00a0mm anterior tooth retraction.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Without attachments or additional forces, clear aligners (CAs) resulted in lingual tipping, extrusion, and distal movement of the central incisor in extraction cases. A labially positioned root amplified lingual tipping and torque loss, whereas a palatally positioned root preserved torque but increased posterior anchorage loss; moreover, shorter roots accentuated tipping and generated peak PDL stresses at the cervical and apical regions, while thinner cortical bone resulted in higher stress.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>SRP and RL significantly affect tooth movement and stress distribution during anterior tooth retraction with CAs in extraction cases, while CBT has minimal impact in tooth movement. The optimal pre-retraction state involves a crown-to-root ratio not exceeding 1.1, with the root positioned upright in the cancellous bone, preventing contact with the labial or palatal cortical bone.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fbioe.2025.1717813","type":"journal-article","created":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T06:36:53Z","timestamp":1763534213000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Biomechanical effects of root\/cortical bone relation on tooth movement during premolar-extraction space closure with clear aligners: a finite element study"],"prefix":"10.3389","volume":"13","author":[{"given":"Yihan","family":"Dong","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ya","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zun","family":"Yang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Weiyi","family":"Gong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Man","family":"Guo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"You","family":"Wu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yun","family":"Hu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Leilei","family":"Zheng","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,11,19]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"3","DOI":"10.25259\/apos_215_2022","article-title":"\u201cClear Aligner Therapy in Contemporary Orthodontics: a Scoping Review of Scholarly Literature.\u201d","volume":"14","author":"Adel","year":"2023","journal-title":"APOS Trends Orthod."},{"key":"B2","doi-asserted-by":"publisher","first-page":"e5756","DOI":"10.7759\/cureus.5756","article-title":"Effect of Bracket Slot and Archwire Dimension on Posterior Tooth Movement in Sliding Mechanics: a Three-Dimensional Finite Element Analysis","volume":"11","author":"Ahmed","year":"2019","journal-title":"Cureus"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1053\/j.sodo.2024.10.005","article-title":"Biomechanics of Tooth Rotation in Clear Aligner Therapy","author":"Aminian","year":"2024","journal-title":"seminars in orthodontics, ahead of print"},{"key":"B4","doi-asserted-by":"publisher","first-page":"108","DOI":"10.1016\/j.ajodo.2016.09.034","article-title":"Long-term changes of the anterior palatal alveolar bone after treatment with bialveolar protrusion, evaluated with computed tomography","volume":"153","author":"Bae","year":"2018","journal-title":"Eval. Comput. Tomogr. Am. J. Orthod. Dentofac. Orthop."},{"key":"B5","doi-asserted-by":"publisher","first-page":"e2839","DOI":"10.1002\/cnm.2839","article-title":"Computational design and engineering of polymeric orthodontic aligners","volume":"33","author":"Barone","year":"2017","journal-title":"Int. J. Numer. Methods Biomed. Eng."},{"key":"B6","doi-asserted-by":"publisher","first-page":"1386","DOI":"10.1002\/JPER.19-0715","article-title":"Gingival phenotype modification therapies on natural teeth: a network meta-analysis","volume":"91","author":"Barootchi","year":"2020","journal-title":"J. Periodontology"},{"key":"B7","doi-asserted-by":"publisher","first-page":"126","DOI":"10.1590\/2176-9451.19.2.126-141.sar","article-title":"Segmented arch or continuous arch technique? A rational approach","volume":"19","author":"Caldas","year":"2014","journal-title":"Dent. Press J. Orthod."},{"key":"B8","doi-asserted-by":"publisher","first-page":"327","DOI":"10.1002\/JPER.20-0149","article-title":"An evidence-based system for the classification and clinical management of non-proximal gingival recession defects","volume":"92","author":"Chambrone","year":"2021","journal-title":"J. Periodontology"},{"key":"B9","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1007\/s00056-019-00175-9","article-title":"Relationship between Alveolar Bone Thickness, Tooth Root Morphology, and Sagittal Skeletal Pattern: a Cone Beam Computed Tomography Study","volume":"80","author":"Co\u015fkun","year":"2019","journal-title":"J. Orofac. Orthop."},{"key":"B10","doi-asserted-by":"publisher","first-page":"679","DOI":"10.2319\/090418-646.1","article-title":"Comparison of achieved and predicted tooth movement of maxillary first molars and central incisors: first premolar extraction treatment with Invisalign","volume":"89","author":"Dai","year":"2019","journal-title":"Angle Orthod."},{"key":"B11","doi-asserted-by":"publisher","first-page":"805","DOI":"10.1016\/j.ajodo.2020.06.041","article-title":"Comparison of achieved and predicted crown movement in adults after 4 first premolar extraction treatment with invisalign","volume":"160","author":"Dai","year":"2021","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B12","doi-asserted-by":"publisher","first-page":"1301","DOI":"10.1177\/00220345810600070301","article-title":"Determination of stress patterns in root-filled teeth incorporating various dowel designs","volume":"60","author":"Davy","year":"1981","journal-title":"J. Dent. Res."},{"key":"B13","doi-asserted-by":"publisher","first-page":"104276","DOI":"10.1016\/j.jdent.2022.104276","article-title":"Effect of trimming line design and edge extension of orthodontic aligners on force transmission: an in vitro study","volume":"125","author":"Elshazly","year":"2022","journal-title":"J. Dent."},{"key":"B14","doi-asserted-by":"publisher","first-page":"434","DOI":"10.1186\/s12903-022-02476-9","article-title":"An expansion to the N\u00e4gerl\u2019s theory of proportionality in reduced alveolar bone height models: a 3D finite element analysis","volume":"22","author":"Geramy","year":"2022","journal-title":"BMC Oral Health 22"},{"key":"B15","doi-asserted-by":"publisher","first-page":"454","DOI":"10.2319\/050714-330.1","article-title":"Initial force systems during bodily tooth movement with plastic aligners and composite attachments: a three-dimensional finite element analysis","volume":"85","author":"Gomez","year":"2015","journal-title":"Angle Orthod."},{"key":"B16","doi-asserted-by":"publisher","first-page":"50","DOI":"10.1016\/j.ajodo.2024.02.012","article-title":"Effect of varying auxiliaries on maxillary incisor torque control with clear aligners: a finite element analysis","volume":"166","author":"Hong","year":"2024","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B17","doi-asserted-by":"publisher","first-page":"557","DOI":"10.1053\/j.sodo.2024.02.006","article-title":"Biomechanical considerations for tooth movement and strategies to avoid undesirable side seminars in orthodontics","volume":"30","author":"Jacob","year":"2024","journal-title":"Manag. Complex Malocclusions"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.25236\/FMSR.050116","article-title":"2023. Research progress of crown -Root ratio in orthodontics","volume":"5","author":"Jinrui","year":"2023","journal-title":"Front. Med. Sci. Res."},{"key":"B19","doi-asserted-by":"publisher","first-page":"38","DOI":"10.1186\/s40510-023-00491-2","article-title":"The displacement of teeth and stress distribution on periodontal ligament under different upper incisors proclination with clear aligner in cases of extraction: a finite element study","volume":"24","author":"Kang","year":"2023","journal-title":"Prog. Orthod."},{"key":"B20","doi-asserted-by":"publisher","first-page":"119","DOI":"10.1590\/2176-9451.20.2.119-125.sar","article-title":"Scientific use of the finite element method in orthodontics","volume":"20","author":"Knop","year":"2015","journal-title":"Sci. Use Finite Elem. Method Orthod. Dent. Press J. Orthod."},{"key":"B21","doi-asserted-by":"publisher","first-page":"20","DOI":"10.1038\/s41368-021-00125-5","article-title":"Biomechanical and biological responses of periodontium in orthodontic tooth movement: Up-Date in a new decade","volume":"13","author":"Li","year":"2021","journal-title":"Int. J. Oral Sci."},{"key":"B22","doi-asserted-by":"publisher","first-page":"44","DOI":"10.1186\/s40510-024-00543-1","article-title":"Seeking orderness out of the orderless movements: an up-to-date review of the biomechanics in clear aligners","volume":"25","author":"Li","year":"2024","journal-title":"Prog. Orthod."},{"key":"B23","doi-asserted-by":"publisher","first-page":"99","DOI":"10.1016\/j.ajodo.2025.02.013","article-title":"Changes in alveolar bone remodeling after maxillary anterior retraction using fixed appliances with different periodontal conditions: a retrospective study based on cone-beam computed tomography","volume":"168","author":"Li","year":"2025","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B24","doi-asserted-by":"publisher","first-page":"316","DOI":"10.1016\/j.ajodo.2007.03.039","article-title":"Torque control of the maxillary incisors in lingual and labial orthodontics: a 3-Dimensional finite element analysis","volume":"135","author":"Liang","year":"2009","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B25","doi-asserted-by":"publisher","first-page":"811","DOI":"10.1016\/j.ajodo.2022.07.021","article-title":"Different biomechanical effects of clear aligners in closing maxillary and mandibular extraction spaces: finite element analysis","volume":"163","author":"Liu","year":"2023","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B26","doi-asserted-by":"publisher","first-page":"239","DOI":"10.1016\/j.ajodo.2022.12.014","article-title":"Biomechanical effects of clear aligners with different thicknesses and gingival-margin morphology for appliance design optimization","volume":"164","author":"Lyu","year":"2023","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B27","doi-asserted-by":"publisher","first-page":"740","DOI":"10.1111\/ocr.12795","article-title":"Biomechanical effects of clear aligner with different shape design at extraction space area during anterior teeth retraction","volume":"27","author":"Mao","year":"2024","journal-title":"Orthod. and Craniofacial Res."},{"key":"B28","doi-asserted-by":"publisher","first-page":"416","DOI":"10.1186\/s12903-023-03106-8","article-title":"Effects of different designs of orthodontic clear aligners on the maxillary central incisors in the tooth extraction cases: a biomechanical study","volume":"23","author":"Meng","year":"2023","journal-title":"BMC Oral Health"},{"key":"B29","doi-asserted-by":"publisher","first-page":"147","DOI":"10.2334\/josnusd.17-0151","article-title":"Cone-beam computed tomographic evaluation of changes in maxillary alveolar bone after orthodontic treatment","volume":"60","author":"Miyama","year":"2018","journal-title":"J. Oral Sci."},{"key":"B30","doi-asserted-by":"publisher","first-page":"cjae072","DOI":"10.1093\/ejo\/cjae072","article-title":"The \u2018roller Coaster Effect\u2019 in premolar extraction cases: clear aligners vs. straight-wire appliance","volume":"47","author":"Qian","year":"2024","journal-title":"Eur. J. Orthod."},{"key":"B31","doi-asserted-by":"publisher","first-page":"558","DOI":"10.1186\/s12903-025-05945-z","article-title":"An integrated approach to posterior Anchorage preparation and incisor torque compensation in premolar extraction cases using clear aligners","volume":"25","author":"Qiang","year":"2025","journal-title":"BMC Oral Health"},{"key":"B32","doi-asserted-by":"publisher","first-page":"635","DOI":"10.1093\/ejo\/cjz103","article-title":"Surgically accelerated orthodontic techniques and periodontal response: a systematic review","volume":"42","author":"Rekhi","year":"2020","journal-title":"Eur. J. Orthod."},{"key":"B33","doi-asserted-by":"publisher","first-page":"359","DOI":"10.1016\/0002-9416(76)90111-1","article-title":"Bioprogressive therapy as an answer to orthodontic needs part II","volume":"70","author":"Ricketts","year":"1976","journal-title":"Part II. Am. J. Orthod."},{"key":"B34","doi-asserted-by":"publisher","first-page":"705","DOI":"10.1016\/j.prosdent.2021.10.006","article-title":"The relationship between tomographic sagittal root position of maxillary anterior teeth and the bone housing","volume":"130","author":"Rodrigues","year":"2023","journal-title":"J. Prosthet. Dent."},{"key":"B35","doi-asserted-by":"publisher","first-page":"11","DOI":"10.18231\/j.ijodr.2024.003","article-title":"Finite element Analysis-A biomechanical tool in orthodontics","volume":"10","author":"Singh","year":"2024","journal-title":"IP Indian J. Orthod. Dentofac. Res."},{"key":"B36","doi-asserted-by":"publisher","first-page":"265","DOI":"10.7518\/hxkq.2019.03.007","article-title":"Finite element analysis of maxillary anterior teeth retraction of posterior teeth with different alveolar bone absorption heights under orthodontic force","volume":"37","author":"Sun","year":"2019","journal-title":"Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi Kouqiang Yixue Zazhi = West China J. Stomatology"},{"key":"B37","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1186\/s13005-021-00277-z","article-title":"Morphological changes of the anterior alveolar bone due to retraction of anterior teeth: a retrospective study","volume":"17","author":"Sun","year":"2021","journal-title":"Head and Face Med."},{"key":"B38","doi-asserted-by":"publisher","first-page":"499","DOI":"10.1016\/0889-5406(87)90232-0","article-title":"Three-dimensional finite element analysis for stress in the periodontal tissue by orthodontic forces","volume":"92","author":"Tanne","year":"1987","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B39","doi-asserted-by":"publisher","first-page":"582","DOI":"10.1016\/j.ajodo.2019.05.011","article-title":"Optimal force magnitude for bodily orthodontic tooth movement with fixed appliances: a systematic review","volume":"156","author":"Theodorou","year":"2019","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B40","doi-asserted-by":"publisher","first-page":"12","DOI":"10.1016\/j.ejwf.2021.11.002","article-title":"Biomechanics of clear aligners: Hidden truths and first principles","volume":"11","author":"Upadhyay","year":"2022","journal-title":"J. World Fed. Orthod."},{"key":"B41","doi-asserted-by":"publisher","first-page":"163","DOI":"10.1016\/j.ajodo.2012.09.010","article-title":"Axes of resistance for tooth movement: does the center of resistance exist in 3-Dimensional space","volume":"143","author":"Viecilli","year":"2013","journal-title":"Am. J. Orthod. Dentofac. Orthop."},{"key":"B42","doi-asserted-by":"publisher","first-page":"23","DOI":"10.1186\/s40510-022-00417-4","article-title":"Biomechanical analysis of effective mandibular En-Masse retraction using class II elastics with a clear aligner: a finite element study","volume":"23","author":"Wang","year":"2022","journal-title":"Prog. Orthod."},{"key":"B43","doi-asserted-by":"publisher","first-page":"1496517","DOI":"10.3389\/fbioe.2024.1496517","article-title":"Biomechanical effects of different mandibular movements and torque compensations during mandibular advancement with clear aligners: a finite element analysis","volume":"12","author":"Wang","year":"2024","journal-title":"Front. Bioeng. Biotechnol."},{"key":"B44","doi-asserted-by":"publisher","first-page":"67","DOI":"10.2319\/040811-250.1","article-title":"Dehiscence and fenestration in skeletal class I, II, and III malocclusions assessed with cone-beam computed tomography","volume":"82","author":"Yagci","year":"2011","journal-title":"Angle Orthod."},{"key":"B45","doi-asserted-by":"publisher","first-page":"1388876","DOI":"10.3389\/fbioe.2024.1388876","article-title":"Effects of different intrusion patterns during anterior teeth retraction using clear aligners in extraction cases: an iterative finite element analysis","volume":"12","author":"Zhang","year":"2024","journal-title":"Front. Bioeng. Biotechnol."},{"key":"B46","doi-asserted-by":"publisher","first-page":"357","DOI":"10.1186\/s12903-025-05726-8","article-title":"The effects of clinical crown length on the sagittal movement of maxillary central incisor in clear aligner treatment: a finite element exploration","volume":"25","author":"Zhou","year":"2025","journal-title":"BMC Oral Health"},{"key":"B47","doi-asserted-by":"publisher","first-page":"628","DOI":"10.1016\/j.ajodo.2022.02.018","article-title":"Finite element analysis of the biomechanical effect of clear aligners in extraction space closure under different Anchorage controls","volume":"163","author":"Zhu","year":"2023","journal-title":"Am. J. Orthod. Dentofac. Orthop."}],"container-title":["Frontiers in Bioengineering and Biotechnology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2025.1717813\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T06:36:55Z","timestamp":1763534215000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fbioe.2025.1717813\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,19]]},"references-count":47,"alternative-id":["10.3389\/fbioe.2025.1717813"],"URL":"https:\/\/doi.org\/10.3389\/fbioe.2025.1717813","relation":{},"ISSN":["2296-4185"],"issn-type":[{"value":"2296-4185","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,19]]},"article-number":"1717813"}}