Abstract
Background
Clear aligner therapy (CAT) has evolved as an esthetic alternative to fixed appliance therapy. However, studies on the effects of attachments on CAT are scarce. This research was done to evaluate the effect of labial and/or palatal attachments on maxillary incisor displacement in CAT through finite element analysis (FEA).
Materials and methods
Finite element modeling was used to create four models with aligners. The following combinations were created: (1) without attachments (WO), (2) with labial attachments (WLA), (3) with palatal attachments (WPA), (4) with labial and palatal attachments (WLPA). Maximum displacement, directional displacement and stresses induced following a palatal displacement of 0.25 mm was evaluated for each of the four models.
Results
Models without attachments and those with palatal attachments showed a greater tooth movement at the incisal part of the crown (0.22 mm and 0.24 mm, respectively) than the models with labial and labiopalatal attachments (0.21 mm and 0.19 mm, respectively). The von Mises stresses were concentrated at the middle third of the roots in the model with the labial attachments (30.257 MPa), while in the other three models, stresses were concentrated at the cervical third of the roots.
Conclusions
Maximum displacement was seen at the incisal third of the maxillary incisors in the model with palatal attachments. The model without attachment generated the highest stresses. However, labial attachments as compared to other models appear to offer some biomechanical advantage by reducing uncontrolled tipping.
Zusammenfassung
Hintergrund
Die Therapie mit Clear Alignern (CAT) hat sich als ästhetische Alternative zur Therapie mit festsitzenden Apparaturen entwickelt. Es gibt jedoch nur wenige Studien über die Auswirkungen von Attachments auf eine CAT. In dieser Studie wurden die Auswirkungen labialer und/oder palatinaler Attachments auf die Verschiebung der Oberkieferschneidezähne bei der CAT mittels FEA (Finite-Elemente-Analyse) untersucht.
Materialien und Methoden
Mittels Finite-Elemente-Modellierung wurden 4 Modelle mit Alignern entwickelt. Die folgenden Kombinationen wurden angefertigt: (1) ohne Attachments (WO), (2) mit labialen Attachments (WLA), (3) mit palatinalen Attachments (WPA), (4) mit labialen und palatinalen Attachments (WLPA). Für jedes der 4 Modelle wurden die maximale Verschiebung, die direktionale Verschiebung und die nach einer palatinalen Verschiebung von 0,25 mm auftretenden Spannungen ermittelt.
Ergebnisse
Die Modelle ohne Attachments und die mit palatinalen Attachments zeigten eine größere Zahnbewegung am inzisalen Teil der Zahnkrone (0,22 bzw. 0,24 mm) als die Modelle mit labialen und labiopalatalen Attachments (0,21 bzw. 0,19 mm). Die Von-Mises-Spannungen waren beim Modell mit den labialen Attachments im mittleren Drittel der Wurzeln konzentriert (30,257 MPa), während sich die Spannungen bei den anderen 3 Modellen auf das zervikale Drittel der Wurzeln konzentrierten.
Schlussfolgerungen
Die maximale Verschiebung wurde im inzisalen Drittel der oberen Schneidezähne beim Modell mit palatinalen Attachments festgestellt. Das Modell ohne Attachment erzeugte die höchsten Spannungen. Allerdings scheinen labiale Attachments im Vergleich zu den anderen einen gewissen biomechanischen Vorteil zu bieten, da sie das unkontrollierte Kippen reduzieren.
Similar content being viewed by others
References
Azaripour A, Weusmann J, Mahmoodi B, Peppas D, Gerhold-Ay A, Van Noorden CJF, Willershausen B (2015) Braces versus Invisalign®: gingival parameters and patients’ satisfaction during treatment: a cross-sectional study. BMC Oral Health 15:69
Fujiyama K, Honjo T, Suzuki M, Matsuoka S, Deguchi T (2014) Analysis of pain level in cases treated with Invisalign aligner: comparison with fixed edgewise appliance therapy. Prog Orthod 15:64
Boyd RL, Waskalic V (2001) Three-dimensional diagnosis and orthodontic treatment of complex malocclusions with the invisalign appliance. Semin Orthod 7(4):274–293
Tai S (2018) Clear aligner technique. Quintessence,
Tuncay OC (ed) (2006) The invisalign system. Quintessence,
Konda P, Tarannum SA (2012) Basic principles of finite element method and its applications in orthodontics. J Pharm Biomed Sci 16:1–18
Papageorgiou SN, Keilig L, Hasan I, Jäger A, Bourauel C (2016) Effect of material variation on the biomechanical behaviour of orthodontic fixed appliances: a finite element analysis. Eur J Orthod 38:300–307
Geramy A (2013) Bodily labializing lateral incisors: 3D analysis using finite element method. Acta Odontol Scand 71:57
Tominaga JY, Chiang PC, Ozaki H, Tanaka M, Koga Y, Bourauel C, Yoshida N (2012) Effect of play between bracket and archwire on anterior tooth movement in sliding mechanics: a three-dimensional finite element study. J Dent Biomech 3:1758736012461269. https://doi.org/10.1177/1758736012461269
Qian Y, Fan Y, Liu Z, Zhang M (2008) Numerical simulation of tooth movement in a therapy period. Clin Biomech 23:S48–S52
Liang W, Rong Q, Lin J, Xu B (2009) Torque control of the maxillary incisors in lingual and labial orthodontics: a 3‑dimensional finite element analysis. Am J Orthod Dentofacial Orthop 135:316–322
Gomez JP, Peña FM, Martınez V, Giraldo DC, Cardona CI (2015) Initial force systems during bodily tooth movement with plastic aligners and composite attachments: A three-dimensional finite element analysis. Angle Orthod 85:454–460
Comba B, Parrini S, Rossini G, Castroflorio T, Deregibus A (2017) A three-dimensional finite element analysis of upper-canine distalization with clear aligners, composite attachments, and Class II elastics. J Clin Orthod 51:24–28
Goto M, Yanagisawa W, Kimura H, Inou N, Maki K (2017) A method for evaluation of the effects of attachments in aligner-type orthodontic appliance: Three-dimensional finite element analysis. Orthod Waves 76(4):207–214
Yokoi Y, Arai A, Kawamura J, Uozumi T, Usui Y, Okafuji N (2019) Effects of attachment of plastic aligner in closing of diastema of maxillary dentition by finite element method. J Healthc Eng :1075097. https://doi.org/10.1155/2019/1075097
Cai Y, Yang X, He B, Yao J (2015) Finite element method analysis of the periodontal ligament in mandibular canine movement with transparent tooth correction treatment. BMC Oral Health 15(1):1–11
Fujita Y, Kimura H, Yanagisawa W, Inou N, Maki K (2014) Experimental verification of finite element analysis for a thermoplastic orthodontic aligner. Showa Univ J Med Sci 26(2):139–147
Ramalho A, Antunes PV (2007) Reciprocating wear test of dental composites against human teeth and glass. Wear 263:1095–1104
Dai FF, Xu TM, Shu G (2019) Comparison of achieved and predicted tooth movement of maxillary first molars and central incisors: first premolar extraction treatment with Invisalign. Angle Orthod 89:679–687
Xu N, Lei X, Yang X, Li X, Ge Z (2018) Three-dimensional finite element analysis on canine teeth distalization by different accessories of bracket-free invisible orthodontics technology. AIP Conf Proc 1955(1):30034
Castroflorio TO, Garino FR, Lazzaro AL, Debernardi CE (2013) Upper-incisor root control with Invisalign appliances. J Clin Orthod 47(6):346–345
Simon M, Keilig L, Schwarze J, Jung BA, Bourauel C (2014) Treatment outcome and efficacy of an aligner technique—regarding incisor torque, premolar derotation and molar distalization. BMC Oral Health 14:68–74
Author information
Authors and Affiliations
Contributions
T. Ahmed: Contributed to conception, design, data acquisition and interpretation, drafted and critically revised the manuscript; S. Padmanabhan: Contributed to conception, design, data acquisition and interpretation, performed all statistical analyses, drafted and critically revised the manuscript; H. Pottipalli Sathyanarayana: Contributed to conception, design, and critically revised the manuscript. All authors gave their final approval and agree to be accountable for all aspects of the work.
Corresponding author
Ethics declarations
Conflict of interest
T. Ahmed, S. Padmanabhan and H. Pottipalli Sathyanarayana declare that they have no competing interests.
Ethical standards
All procedures performed in studies involving human participants or on human tissue were in accordance with the ethical standards of the institutional and/or national research committee and with the 1975 Helsinki declaration and its later amendments or comparable ethical standards. Institutional Ethics Committee of Sri Ramachandra Institute of Higher Education and Research, Chennai, India [Number CSP/19/JUN/78/245].
Additional information
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Ahmed, T., Padmanabhan, S. & Pottipalli Sathyanarayana, H. Effects of varying attachment positions on palatal displacement of maxillary incisors with clear aligner therapy. J Orofac Orthop 84, 178–188 (2023). https://doi.org/10.1007/s00056-021-00374-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00056-021-00374-3