Trimline Length As A Variable In Aligner-Based Distalization A Finite Element Analysis Study

Yıl 2025, Cilt: 14 Sayı: 3, 168 - 176, 29.09.2025

Tulca Büyükpatır Türk , Ebru Küçükkaraca

https://doi.org/10.54617/adoklinikbilimler.1648020

Öz

AIM: This study aimed to evaluate the impact of aligner trimline length on the movement of the upper second molar during the distalization process.
MATHERIALS AND METHOD: Two finite element models were developed utilizing different aligner trimline lengths. One model featured a trimline at the gingiva (Mode A1), while the other had a trimline positioned 2 mm above it (Model A2). Both models were applied to a 3D full-toothed maxillary model, excluding the upper third molars. During the simulation, a distal displacement of 0.25 mm was applied to the upper first and second molars. The results regarding von Mises stress associated with the upper second molar and its periodontal ligament, as well as the tooth displacement data, were analyzed.
RESULTS: The stresses in the apical region of the periodontal ligament (PDL) increased with longer trimlines. The crown displayed stress areas mainly on the mesial side in both models. In Model A2, stresses began to extend distally, and the stresses on the roots also increased. Both groups exhibited rotation in the distal direction, and Model A2 showed a greater distal crown displacement.
CONCLUSION: Increasing the trimline length is a more effective approach for managing the movement of upper second molar teeth during distalization.

Anahtar Kelimeler

Biomechanics , Clear aligners , Distalization , Finite element analysis

Etik Beyan

This study was approved by the Ethics Committee of Ankara Yıldırım Beyazıt University Health Sciences with the approval number 2024/600.

Teşekkür

The authors would like to express their gratitude to Tinus Technologies for their invaluable support in the acquisition and analysis of data, particularly through finite element analysis.

Şeffaf Plaklarla Gerçekleştirilen Distalizasyonda Bir Değişken Olarak Trim Hattı Uzunluğu: Sonlu Elemanlar Analiz Çalışması

Öz

GİRİŞ: Bu çalışmanın amacı distalizasyon işlemi sırasında şeffaf plaklara ait trimline uzunluğunun üst ikinci molar dişin hareketi üzerindeki etkisini değerlendirmektir.
GEREÇ VE YÖNTEM: Farklı şeffaf plak trim hattı uzunlukları kullanılarak iki sonlu eleman modeli geliştirilmiştir. Modellerden birinde dişetinde bir trim hattı bulunurken (Model A1), diğerinde bunun 2 mm üzerinde konumlandırılmış bir trim hattı mevcuttur (Model A2). Her iki model de üst üçüncü molar dişler hariç olmak üzere 3D tam dişli bir maksiller modele uygulanmıştır. Simülasyon sırasında, üst birinci ve ikinci azı dişlerine 0,25 mm'lik bir distal deplasman uygulanmıştır. Diş yer değiştirme verilerinin yanı sıra üst ikinci molar diş ve periodontal ligamenti ile ilişkili von Mises stresine ait sonuçlar analiz edilmiştir.
BULGULAR: Periodontal ligamentin (PDL) apikal bölgesindeki stresler daha uzun trim hatları ile artmıştır. Kuron, her iki modelde de esas olarak mezial tarafta stres alanları sergilemiştir. Model A2'de stresler distale doğru yayılmaya başlamış ve köklerdeki stresler de artmıştır. Her iki grup da distal yönde rotasyon sergilemiş ve Model A2 daha büyük bir distal kuron yer değiştirmesi göstermiştir.
SONUÇLAR: Trimline uzunluğunun artırılması, distalizasyon sırasında üst ikinci molar dişlerin hareketini yönetmek için daha etkili bir yaklaşımdır.

Anahtar Kelimeler

Biyomekanik , Distalizasyon , Sonlu elemanlar analizi , Şeffaf plak

Kaynakça

• 1. Boyd RL. Complex orthodontic treatment using a new protocol for the Invisalign appliance. J Clin Orthod 2007;41:525-47.
• 2. Galan-Lopez L, Barcia-Gonzalez J, Plasencia E. A systematic review of the accuracy and efficiency of dental movements with Invisalign(R). Korean J Orthod 2019;49:140-9.
• 3. Simon M, Keilig L, Schwarze J, Jung BA, Bourauel C. Treatment outcome and efficacy of an aligner technique--regarding incisor torque, premolar derotation and molar distalization. BMC Oral Health 2014;14:68.
• 4. Garino F, Castroflorio T, Daher S, Ravera S, Rossini G, Cugliari G, et al. Effectiveness of composite attachments in controlling upper-molar movement with aligners. J Clin Orthod 2016;50:341-7.
• 5. Kinzinger GS, Eren M, Diedrich PR. Treatment effects of intraoral appliances with conventional anchorage designs for noncompliance maxillary molar distalization: A literature review. Eur J Orthod 2008;30:558-71.
• 6. Schupp W, Haubrich J, Neumann I. Class II correction with the Invisalign system. J Clin Orthod 2010;44:28-35.
• 7. Ravera S, Castroflorio T, Garino F, Daher S, Cugliari G, Deregibus A. Maxillary molar distalization with aligners in adult patients: A multicenter retrospective study. Prog Orthod 2016;17:12.
• 8. Caruso S, Nota A, Ehsani S, Maddalone E, Ojima K, Tecco S. Impact of molar teeth distalization with clear aligners on occlusal vertical dimension: A retrospective study. BMC Oral Health 2019;19:182.
• 9. Gomez JP, Peña FM, Martínez V, Giraldo DC, Cardona CI. Initial force systems during bodily tooth movement with plastic aligners and composite attachments: A three-dimensional finite element analysis. Angle Orthod 2015;85:454-60.
• 10. Fan D, Liu H, Yuan C-Y, Wang S-Y, Wang P-L. Effectiveness of the attachment position in molar intrusion with clear aligners: A finite element study. BMC Oral Health 2022;22:474.
• 11. Kim WH, Hong K, Lim D, Lee JH, Jung YJ, Kim B. Optimal position of attachment for removable thermoplastic aligner on the lower canine using finite element analysis. Materials 2020;13:3369.
• 12. Dai F-F, Xu T-M, Shu G. Comparison of achieved and predicted tooth movement of maxillary first molars and central incisors: First premolar extraction treatment with Invisalign. Angle Orthod 2019;89:679-87.
• 13. Elshazly TM, Salvatori D, Elattar H, Bourauel C, Keilig L. Effect of trimming line design and edge extension of orthodontic aligners on force transmission: A 3D finite element study. J Mech Behav Biomed Mater 2023;140:105741.
• 14. Elshazly TM, Keilig L, Salvatori D, Chavanne P, Aldesoki M, Bourauel C. Effect of trimming line design and edge extension of orthodontic aligners on force transmission: An in vitro study. J Dent 2022;125:104276.
• 15. Karsli N, Yildirim F, Dingiloğlu A, Özsoy ÖP. Does the trimline extension and attachment size affect maxillary arch expansion in clear aligner therapy? A finite element study. Australasian Orthodontic Journal Sciendo, 2024;40:121-33.
• 16. Traversa F, Chavanne P, Mah J. Biomechanics of clear aligner therapy: Assessing the influence of tooth position and flat trimline height in translational movements. Orthod Craniofac Res 2025;28:1-11.
• 17. Cowley DP, Mah J, O’Toole B. The effect of gingival-margin design on the retention of thermoformed aligners. J Clin Orthod 2012;46:697-705.
• 18. Rossini G, Schiaffino M, Parrini S, Sedran A, Deregibus A, Castroflorio T. Upper second molar distalization with clear aligners: A finite element study. Appl Sci 2020;10:7739.
• 19. Ayidağa C, Kamiloğlu B. Effects of variable composite attachment shapes in controlling upper molar distalization with aligners: A nonlinear finite element study. J Healthc Eng 2021;5557483.
• 20. Savignano R, Valentino R, Razionale AV, Michelotti A, Barone S, D’Anto V. Biomechanical effects of different auxiliary-aligner designs for the extrusion of an upper central ıncisor: A finite element analysis. J Healthc Eng 2019;9687127.
• 21. Geramy A, Shahroudi AS. Fixed versus removable appliance for palatal expansion; A 3D analysis using the finite element method. J Dent 2014;11:75.
• 22. Hedayati Z, Shomali M. Maxillary anterior en masse retraction using different antero-posterior position of mini screw: A 3D finite element study. Prog Orthod 2016;17:1-7.
• 23. Wu J-l, Liu Y-f, Peng W, Dong H-y, Zhang J-x. A biomechanical case study on the optimal orthodontic force on the maxillary canine tooth based on finite element analysis. J Zhejiang Univ Sci B 2018;19:535.
• 24. Liu X, Cheng Y, Qin W, Fang S, Wang W, Ma Y, et al. Effects of upper-molar distalization using clear aligners in combination with Class II elastics: A three-dimensional finite element analysis. BMC Oral Health 2022;22:546.
• 25. Gao L, Wichelhaus A. Forces and moments delivered by the PET-G aligner to a maxillary central incisor for palatal tipping and intrusion. Angle Orthod 2017;87:534-41.
• 26. Yu I-J, Kook Y-A, Sung S-J, Lee K-J, Chun Y-S, Mo S-S. Comparison of tooth displacement between buccal mini-implants and palatal plate anchorage for molar distalization: A finite element study. Eur J Orthod 2014;36:394-402.
• 27. Comba B, Parrini S, Rossini G, Castroflorio T, Deregibus A. A three-dimensional finite element analysis of upper-canine distalization with clear aligners, composite attachments, and class II elastics. J Clin Orthod 2017;51:24-8.
• 28. Su R, Li S, Wang W. Effect of high trimline aligners on distalizing mandibular molars: a three-dimensional finite element study. Eur J Med Res. 2024;29:623.
• 29. Elfouly D, El-Harouni NM, Ismail HA, El-Bialy T, Ghoneima A. Tip, torque and rotation of maxillary molars during distalization using Invisalign: A CBCT study. BMC Oral Health 2024;24:797.
• 30. Nakornnoi T, Srirodjanakul W, Chintavalakorn R, Santiwong P, Sipiyaruk K. The biomechanical effects of clear aligner trimline ndesigns and extensions on orthodontic tooth movement: A systematic review. BMC Oral Health 2024;24:1523.