Article ID: WMC005407 ISSN 2046-1690

Clear Aligners: strenghts and weaknesses

Peer review status: No

Corresponding Author: Dr. Debora Loli, DDS, Sapienza University of Rome - Department of Oral and MaxilloFacial Sciences - Italy

Submitting Author: Dr. Debora Loli, DDS, Sapienza University of Rome - Department of Oral and MaxilloFacial Sciences - Italy

Article ID: WMC005407 Article Type: Review articles Submitted on:20-Nov-2017, 10:30:33 PM GMT Published on: 23-Nov-2017, 12:17:09 PM GMT Article URL: http://www.webmedcentral.com/article_view/5407 Subject Categories: Keywords:, orthodontic treatment, strenghts and weaknesses, advantages How to cite the article:Loli D. Clear Aligners: strenghts and weaknesses. WebmedCentral ORTHODONTICS 2017;8(11):WMC005407 Copyright: This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source(s) of Funding: none

Competing Interests: none

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Clear Aligners: strenghts and weaknesses

Author(s): Loli D

Abstract Aim of this review is the knowledge of advantages and weaknesses of clear aligners. Keywords used are: Clear aligners are orthodontic devices that use elastic clear aligner, comparative effectiveness research, thermoplastic material that applies pressure to the orthodontic appliances. PubMed and Scopus were teeth to move into the aligner’s position, which are used. 25 articles were selected. an alternative to . They are esthetic, efficient, and comfortable compared to traditional fixed Review appliance for mild-to-moderate . Clear aligners have many advantages principally for adult patient but also some disadvantages. The clinician Several clinical papers5-12 have been published should know strenghts and weaknesses of aligners for throughout the last five years, showing the applicability a correct use on the basis on clinical indications. of the technique in correcting various types of Introduction . The foremost frustration is with patient compliance. Changing aligners prematurely leads to loss of tracking. Prior to the introduction of clear aligners, the most widely used appliance was an adjunct to fixed The second most common performance problem is the appliances, which was worn once the bands and extrusion of teeth, especially the maxillary lateral brackets were removed. incisor. It may happen because of delayed movements of adjacent teeth, particularly the canines13. The Positioner introduced by Kesling (1945) was originally made of vulcanite material and aided the The third significant weakness is the aligner’s settling- in process; but it was also useful in correcting inability to move the root apex, such as in torqueing or certain tooth positions that could not be finished for translational movements. The role of uncontrolled one reason or another by fixed appliances1. tipping and loss of complicates the progression of programmed aligners. Further Later, latex became the standard material to evaluation of patient characteristics, such as age, manufacture. But even earlier, Remmensnyder had bone quality, and tooth morphometrics could aid in introduced the Flex-O-Tite gum-massaging appliance aligner treatment planning14. in 1926 to aid in the treatment of gingival disease.2 He 15 reported that he was observing tooth movements as a Rossini et al suggested that most studies had side effect. methodological problems: small sample size, bias and confounding variables, lack of method error analysis, The first thermoformed plastic sheet to move teeth blinding in measurements, and deficient or missing was invented by Nahoum in 19643. He called it the statistical methods. The quality level of the studies Dental Contour Appliance. was not sufficient to draw any evidence-based Subsequently it was modified by Sheridan (1993) and conclusions. called the Essix Appliance4. Aligner is an effective procedure that is able to align The Invisalign method is gaining an increasing interest and level the arches in non-growing subjects. The as an alternative treatment option in adult patients to anterior movement achievable is comparable simplify the treatment plan. to that reported for the straight wire technique. Particularly since the introduction of Invisalign Aligner is not effective in controlling anterior extrusion appliances (Align Technology) in 1998, clear aligners movement. Contrasting results have been reported in have become an increasingly common addition to the relation to the posterior vertical control, and a definite orthodontic armamentarium. conclusion cannot be drawn. Methods  t is not effective in controlling rotations, especially of rounded teeth. Aligner is effective in controlling upper molar bodily movement when a distalization of 1.5 mm

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has been prescribed. disease21. It is not based on aligners alone. It requires the use of Routine follow-up dental checks are fast, such as auxiliaries (attachments, interarch , IPR, instruments needed. altered aligner geometries) to improve the They can be used also for mild vertical correction predictability of orthodontic movement. because of clear aligners can intrude the posterior Therefore clinical cases such as extraction cases, teeth and close the anterior openbite. Cases such as monolateral , skeletal crossbite, movements mild dentoalveolar open bite, which had previously of roots, presurgical cases, full-cusp Class II or III been treated exclusively with fixed appliances, can be malocclusions (also subdivision malocclusions), resolved efficiently, while simultaneously maintaining rotations severe over 15°, vertical movements major facial esthetics, using clear aligners22. of 2 mm can be very complex to challenge with The clinician can use ClinCheck such as diagnostic aligner. tool23. Despite claims about the effectiveness of clear The amount of (IPR) aligners, evidence is generally lacking. Shortened performed should be about the same as with fixed treatment duration and chair time in mild-to-moderate appliances. IPR should be limited for Bolton’s cases appear to be the only significant effectiveness of discrepancy and need to alter the tooth morphology. clear aligners over conventional systems that are IPR has not been shown to adversely affect dental or 16 supported by the current evidence . The retention to periodontal health24-25. avoid the risk of relapse in particular crossbite, diastemas and open bite is necessary.   Conclusions Patients experience esthetic improvement and comfort. Clear-aligner use have less impact on daily life during treatment than the use of fixed appliance and there The clinician may use clear aligners in clinical practical are no significant changes at 12 months 17. to facilitate some clinical cases. The knowledge of limits and advantages is fundamental. The treatment Aligners are also indicated in patients with offered several advantages in terms of maintenance of amelogenesis imperfecta or prosthetic crowns with oral hygiene and comfortable management of the porcelain surfaces or bridge; the clinician doesn’t removable appliance. Finally, patient satisfaction was worry about securing brackets onto such surfaces18. recorded as very high, because they underwent an With the aligners, even some patients with invisible orthodontic treatment and they reached less-than-perfect oral hygiene do not exhibit white optimal esthetics and, above all, their occlusion was enamel spots or decalcifications. functionally rehabilitated. In conclusion, for all the Some studies analyzed the entity of root resorption. above-mentioned reasons, the principal indication for 19 Gay et al investigated the incidence and severity of use of clear aligners is in adult patients with restorative root resorption in adult patients treated with aligners and/or multidisciplinary concerns or needs such as during class I treatments. Every patient showed a patients with risk of developing periodontal disease, minimum of one tooth with root length reduction. On allergy to metals, mild malocclusions. The retention to average, 6.39 teeth per patient were affected. Overall, reduce the risk of relapse in particular in crossbite, 41.81% of the measured 1083 teeth showed signs of diastemas and open bite is necessary.   apical root resorption, but only 3.69% a reduction of over 20% of the pre-treatment root length. Severe root References resorption affected mostly the upper lateral incisors and lower lateral and central incisors.

Compared with fixed appliances and untreated control 1. Kesling HD: The philosophy of the tooth patients, the periodontal tissue health as measured by positioning appliance. Am J Orthod papillary bleeding score and periodontal pocket depth 1945;31:297-304 improves with use of clear aligners during orthodontic 2. Remmensnyder O: A gum-massaging appliance in the treatment of pyorrhea. Dent Cosmos treatment.20 Patients undergoing orthodontic treatment 1926;28:381-384 ® with the Invisalign  System show a superior 3. Nahoum HI: The vacuum formed dental contour periodontal health in the short-term when compared to appliance. NY State Dent J 1964; 385-390 patients in treatment with fixed orthodontic appliances. 4. Sheridan JJ, LeDoux W, McMinn R: Essix Invisalignshould be considered as a first-line treatment retainers: fabrication and supervision for permanent retention. J Clin Orthod 1993; 27: option in patients with risk of developing periodontal

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37-45 Caprioglio A, Abbate GM. Periodontal health 5.  Boyd RL. Complex orthodontic treatment using status in patients treated with the a new protocol for the Invisalign Invisalign system and fixed orthodontic appliance. JCO. 2007;41(9):525–547. appliances: A 3 months clinical and 6. Boyd RL, Vlaskalic V. Three-dimensional microbiological evaluation Eur J Dent. 2015 diagnosis and orthodontic treatment of complex Jul-Sep; 9(3): 404–410 malocclusions with Invisalign appliance. Semin 22. Guarneri MP ; Oliverio T ; Silvestre I ; Lombardo Orthod. 2001;7–4:274–293. L ;  Siciliani G.Open bite treatment using clear 7. Djeu G, Shelton C, Maganzini A. Outcome aligners Angle Orthod. 2013;83:913–919 assessment of Invisalign and traditional 23. Duong T, Derakhshan M: Advantages of the orthodontic treatment compared with the American Invisalign system. In The Invisalign system. Berlin: Board of Orthodontic objective grading Quintessence, 2006 system. Am J Orthod Dentofacial 24. Mietke RR, Jost-Brinkmann PG: interproximal Orthop. 2005;128(3):292–298.  enamel reduction. In The Invisalign system. Berlin: 8. Giancotti A, Greco M, Mampieri G. Extraction Quintessence,2006 treatment using Invisalign technique. Prog 25. Fillion D, Teil II: Vor-und Nachteile der appximalen Orthod. 2006;7(1):31–43. Schmelzreduktion. Int Orthod Kieferorthop 1995; 9. Giancotti A, Ronchin M. Pre-restorative treatment 27:64-90 with the Invisalign system. JCO. 2006;40(11):679–682.  10. Honn M, Goz G. A premolar extraction case using the Invisalign system. J Orofac Orthop. 2006;67(5):385–394.  11. Kuncio D, Maganzini A, Shelton C, Freeman K. Invisalign and traditional orthodontic treatment post-retention outcomes compared using the American Board of Orthodontics objective grading system. Angle Orthod. 2007;77(5):864–869. 12. Lagravère MO, Flores-Mir C. The treatment effects of Invisalign orthodontic aligners: a systematic review. J Am Dent Assoc. 2005;136(12):1724–1729. 13. Nord S: An exploratory study to identify the conditions that induce loss of tacking in tooth movement with the Invisalign system. Masters Thesis, Temple University, 2005. 14. Carl T. Drake, Susan P. McGorray, Calogero Dolce, Madhu Nair, Timothy T. Wheeler. Orthodontic Tooth Movement with Clear Aligners ISRN Dent. 2012; 2012: 657973. 15. Rossini G, Parrini S, Castroflorio T., Deregibus A, Debernardi C.L. Efficacy of clear aligners in controlling orthodontic tooth movement: A systematic review. : September 2015, Vol. 85, No. 5, pp. 881-889. 16. Zheng M, Liu R, Ni Z, Yu Z. Efficiency, effectiveness and treatment stability of clear aligners: A systematic review and meta-analysis. Orthod Craniofac Res. 2017;00:1–7. 17. Feiou Lin, Linjie Yao, Chandradev Bhikoo, Jing Guo impact of fixed orthodontic appliance or clear-aligner on daily performance, in adult patients with moderate need for treatmentPatient Prefer Adherence. 2016; 10: 1639–1645 18. Weir T Clear aligners in orthodontic treatment.Aust Dent J. 2017 Mar;62 Suppl 1:58-62. 19. Gay G, Ravera S, Castroflorio T, Garino F, Rossini G, Parrini S, Cugliari G, Deregibus A. Root resorption during orthodontic treatment with Invisalign®: a radiometric study. Prog Orthod. 2017; 18: 12 20. Taylor MG, McGorray SP, Durret S, et al: Effect of Invisalign aligners on periodontal tissues. J Dent Res 2003;82:1483 21. Levrini L, Mangano A, Montanari P, Margherini S,

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