Korean J Orthod.  2024 Nov;54(6):403-410. 10.4041/kjod24.093.

Comparison of the predicted and achieved labiolingual inclinations of the maxillary central incisors in adult Class II division 2 malocclusions treated with clear aligners

• Al-Samman M
• Sadek M
• Hamdan AM

• KMID: 2561601
• DOI: http://doi.org/10.4041/kjod24.093

Abstract

Objective
This study aimed to compare the predicted and achieved labiolingual inclinations of the maxillary central incisors in adult Class II division 2 malocclusions treated with clear aligners using Power Ridges^® and composite attachments.
Methods
This retrospective study included 24 patients (mean age, 26.5 ± 3.3 years). The patients had Class II division 2 malocclusion and were treated with non-extraction with Invisalign^® clear aligners with either Power Ridges^® or composite attachments to enhance the predictability of required change in labiolingual inclination for the maxillary central incisors. Before treatment, treatment prediction and final digital models were exported as stereolithography files and superimposed using the eModel 9.0 “Compare” software. The predicted and achieved labiolingual incisor inclinations were compared.
Results
The mean accuracies of the achieved inclination of the central incisors were 68.3% in the Power Ridges^® group and 71.6% in the attachments group. No statistically significant differences in predictability were found between the groups (P > 0.05). A low positive correlation was observed between the predicted inclination change and the average absolute difference between the predicted and achieved inclinations (r = 0.19).
Conclusions
Predicted labiolingual inclination is not fully achieved with clear aligners in both the Power Ridges^® and attachment groups. Clinicians must take measures to counteract this limitation, specifically in Class II division 2 cases.

Keyword

Aligners; Digital models; Class II; Tooth movement

Figure

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  Figure 1 Power Ridges® feature (arrows) in Invisalign® clear aligners.

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  Figure 2 Horizontal rectangular attachments placed on the center of the labial surface of maxillary central incisors (4 mm long, 2 mm wide, and 1 mm thick).

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  Figure 3 Tooth measurements performed on digital models using the “Compare” software. A, Segmentation of the digital models (TS and T1). B, Best-fit surface registration algorithm automatically superimposes individual teeth from the segmented models (TS or T1) on the corresponding teeth in the unsegmented T0 model. C, Local tooth reference frame that the software automatically generates, defining the principal local coordinate tooth axes being generated (Automated Tooth Coordinates).

Reference

1. Nanda RS, Tosun Y. 2010. Biomechanics in orthodontics: principles and practice. Quintessence Pub Co.;Chicago: p. 99. https://search.worldcat.org/ko/title/892430513. DOI: 10.5005/jp/books/12999.

2. Andrews LF. 1972; The six keys to normal occlusion. Am J Orthod. 62:296–309. https://doi.org/10.1016/s0002-9416(72)90268-0. DOI: 10.1016/S0002-9416(72)90268-0. PMID: 4505873.

3. Archambault A, Lacoursiere R, Badawi H, Major PW, Carey J, Flores-Mir C. 2010; Torque expression in stainless steel orthodontic brackets. A systematic review. Angle Orthod. 80:201–10. https://doi.org/10.2319/080508-352.1. DOI: 10.2319/080508-352.1. PMID: 19852662. PMCID: PMC8978750.

4. Wagner JA, Nikolai RJ. 1985; Stiffness of incisor segments of edgewise arches in torsion and bending. Angle Orthod. 55:37–50. https://doi.org/10.1043/0003-3219(1985)055<0037:Soisoe>2.0.Co;2.

5. Rauch ED. 1959; Torque and its application to orthodontics. Am J Orthod. 45:817–30. https://doi.org/https://doi.org/10.1016/0002-9416(59)90222-2. DOI: 10.1016/0002-9416(59)90222-2.

6. Rossini G, Parrini S, Castroflorio T, Deregibus A, Debernardi CL. 2015; Efficacy of clear aligners in controlling orthodontic tooth movement: a systematic review. Angle Orthod. 85:881–9. https://doi.org/10.2319/061614-436.1. DOI: 10.2319/061614-436.1. PMID: 25412265. PMCID: PMC8610387.

7. Huang AT, Huang D. Huang AT, Huang D, editors. 2022. Power Ridges: how powerful are they?. Controversies in clear aligner therapy. Springer, Cham;Cham: p. 125–34. https://doi.org/10.1007/978-3-030-92810-0_8. DOI: 10.1007/978-3-030-92810-0_8.

8. Nucera R, Dolci C, Bellocchio AM, Costa S, Barbera S, Rustico L, et al. 2022; Effects of composite attachments on orthodontic clear aligners therapy: a systematic review. Materials (Basel). 15:533. https://doi.org/10.3390/ma15020533. DOI: 10.3390/ma15020533. PMID: 35057250. PMCID: PMC8778413.

9. 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. https://doi.org/10.1186/1472-6831-14-68. DOI: 10.1186/1472-6831-14-68. PMID: 24923279. PMCID: PMC4068978.

10. Grünheid T, Gaalaas S, Hamdan H, Larson BE. 2016; Effect of clear aligner therapy on the buccolingual inclination of mandibular canines and the intercanine distance. Angle Orthod. 86:10–6. https://doi.org/10.2319/012615-59.1. DOI: 10.2319/012615-59.1. PMID: 26000701. PMCID: PMC8603951.

11. Pavoni C, Lione R, Laganà G, Cozza P. 2011; Self-ligating versus Invisalign: analysis of dento-alveolar effects. Ann Stomatol (Roma). 2:23–7. https://pubmed.ncbi.nlm.nih.gov/22238719/. PMID: 22238719. PMCID: PMC3254387.

12. Kravitz ND, Kusnoto B, BeGole E, Obrez A, Agran B. 2009; How well does Invisalign work? A prospective clinical study evaluating the efficacy of tooth movement with Invisalign. Am J Orthod Dentofacial Orthop. 135:27–35. https://doi.org/10.1016/j.ajodo.2007.05.018. DOI: 10.1016/j.ajodo.2007.05.018. PMID: 19121497.

13. Haouili N, Kravitz ND, Vaid NR, Ferguson DJ, Makki L. 2020; Has Invisalign improved? A prospective follow-up study on the efficacy of tooth movement with Invisalign. Am J Orthod Dentofacial Orthop. 158:420–5. https://doi.org/10.1016/j.ajodo.2019.12.015. DOI: 10.1016/j.ajodo.2019.12.015. PMID: 32620479.

14. Robertson L, Kaur H, Fagundes NCF, Romanyk D, Major P, Flores Mir C. 2020; Effectiveness of clear aligner therapy for orthodontic treatment: a systematic review. Orthod Craniofac Res. 23:133–42. https://doi.org/10.1111/ocr.12353. DOI: 10.1111/ocr.12353. PMID: 31651082.

15. Jiang T, Jiang YN, Chu FT, Lu PJ, Tang GH. 2021; A cone-beam computed tomographic study evaluating the efficacy of incisor movement with clear aligners: assessment of incisor pure tipping, controlled tipping, translation, and torque. Am J Orthod Dentofacial Orthop. 159:635–43. https://doi.org/10.1016/j.ajodo.2019.11.025. DOI: 10.1016/j.ajodo.2019.11.025. PMID: 33583693.

16. Hahn W, Zapf A, Dathe H, Fialka-Fricke J, Fricke-Zech S, Gruber R, et al. 2010; Torquing an upper central incisor with aligners-acting forces and biomechanical principles. Eur J Orthod. 32:607–13. https://doi.org/10.1093/ejo/cjq007. DOI: 10.1093/ejo/cjq007. PMID: 20462912.

17. Gaddam R, Freer E, Kerr B, Weir T. 2021; Reliability of torque expression by the Invisalign® appliance: a retrospective study. Aust Orthod J. 37:3–13. https://doi.org/doi:10.21307/aoj-2021-001. DOI: 10.21307/aoj-2021-001. PMID: d27387a0f74a49249781cb7d7339519c.

18. Karras T, Singh M, Karkazis E, Liu D, Nimeri G, Ahuja B. 2021; Efficacy of Invisalign attachments: a retrospective study. Am J Orthod Dentofacial Orthop. 160:250–8. https://doi.org/10.1016/j.ajodo.2020.04.028. DOI: 10.1016/j.ajodo.2020.04.028. PMID: 34217574.

19. Mehta S, Patel D, Yadav S. 2021; Staging orthodontic aligners for complex orthodontic tooth movement. Turk J Orthod. 34:202–6. https://doi.org/10.5152/TurkJOrthod.2021.20116. DOI: 10.5152/TurkJOrthod.2021.20116. PMID: 35110192. PMCID: PMC8940221. PMID: 6c96ef387fff4146af954b482e1ad644.

20. Adel SM, Vaid NR, El-Harouni N, Kassem H, Zaher AR. 2022; Tip, torque & rotations: how accurately do digital superimposition software packages quantify tooth movement? Prog Orthod. 23:8. https://doi.org/10.1186/s40510-022-00402-x. DOI: 10.1186/s40510-022-00402-x. PMID: 35284950. PMCID: PMC8918442. PMID: d41f35533487482bb32df4e53f5a7cee.

21. Dahlberg G. 1940; Statistical methods for medical and biological students. Br Med J. 2:358–9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2179091/pdf/brmedj04110-0016c.pdf. DOI: 10.1136/bmj.2.4158.358-b. PMCID: PMC2179091.

22. Lin LI. 1989; A concordance correlation coefficient to evaluate reproducibility. Biometrics. 45:255–68. https://pubmed.ncbi.nlm.nih.gov/2720055/. DOI: 10.2307/2532051. PMID: 2720055.

23. Danz JC, Greuter C, Sifakakis I, Fayed M, Pandis N, Katsaros C. 2014; Stability and relapse after orthodontic treatment of deep bite cases-a long-term follow-up study. Eur J Orthod. 36:522–30. https://doi.org/10.1093/ejo/cjs079. DOI: 10.1093/ejo/cjs079. PMID: 23197574.

24. Sandhya V, Arun AV, Reddy VP, Mahendra S, Chandrashekar BS, Aravind . 2022; Biomechanical effects of torquing on upper central incisor with thermoplastic aligner: a comparative three-dimensional finite element study with and without auxillaries. J Indian Orthod Soc. 56:49–56. https://doi.org/10.1177/0301574220974340. DOI: 10.1177/0301574220974340.

25. Castroflorio T, Garino F, Lazzaro A, Debernardi C. 2013; Upper-incisor root control with Invisalign appliances. J Clin Orthod. 47:346–51. quiz 387https://pubmed.ncbi.nlm.nih.gov/23863556/.

26. Upadhyay M, Arqub SA. 2022; Biomechanics of clear aligners: hidden truths & first principles. J World Fed Orthod. 11:12–21. https://doi.org/10.1016/j.ejwf.2021.11.002. DOI: 10.1016/j.ejwf.2021.11.002. PMID: 34965910.

27. Simon M, Keilig L, Schwarze J, Jung BA, Bourauel C. 2014; Forces and moments generated by removable thermoplastic aligners: incisor torque, premolar derotation, and molar distalization. Am J Orthod Dentofacial Orthop. 145:728–36. https://doi.org/10.1016/j.ajodo.2014.03.015. DOI: 10.1016/j.ajodo.2014.03.015. PMID: 24880843.

28. Cheng Y, Gao J, Fang S, Wang W, Ma Y, Jin Z. 2022; Torque movement of the upper anterior teeth using a clear aligner in cases of extraction: a finite element study. Prog Orthod. 23:26. https://doi.org/10.1186/s40510-022-00421-8. DOI: 10.1186/s40510-022-00421-8. PMID: 35909188. PMCID: PMC9339452. PMID: f3e1a15f9ed34301b4003fff6fc9978f.