The Art of Holding Smiles: A Contemporary Review on Orthodontic Retainers

Abstract

Retention represents a critical phase in orthodontic treatment, ensuring the stability of tooth alignment achieved after active therapy. This review explores the evolution, classification, and modern innovations in orthodontic retention. It highlights the design principles, materials, and clinical applications of both removable and fixed retainers, including traditional appliances such as the Hawley and newer options like Essix, Memotain, and CAD/CAM-fabricated retainers. Advances in biomaterials, particularly PEEK, shape memory alloys, and nanocomposites have enhanced the mechanical strength, biocompatibility, and aesthetic appeal of retainers, contributing to better patient comfort and compliance. The article also discusses the effects of different retainers on periodontal health, the importance of oral hygiene maintenance, and the survival and failure rates associated with various designs. Furthermore, emerging smart materials and digital fabrication technologies are paving the way for adaptive, precision-engineered retention systems. Overall, this review underscores that successful long-term orthodontic outcomes depend on individualized retainer selection, proper maintenance, and ongoing professional supervision. Through the integration of advanced materials and digital design, modern orthodontics continues to refine the art of maintaining smiles with durability, comfort, and long-term stability.

Introduction

Retention is the final and most essential phase of orthodontic treatment, aimed at maintaining the corrected tooth positions after active therapy. Because teeth naturally tend to relapse due to periodontal fiber elasticity, growth, and muscular forces, retainers are required to stabilize the dentition while tissues remodel. Over time, a wide range of removable and fixed retainers has been developed, from traditional Hawley appliances to modern thermoplastic, fiber-reinforced, and CAD/CAM-based designs. Advances in biomaterials such as PEEK, nanocomposites, and shape-memory alloys have improved durability, biocompatibility, and aesthetics. Retainer selection depends on treatment needs, patient compliance, comfort, hygiene, and long-term stability.

Types of Retainers

1. Removable Retainers

Used typically for 6–12 months post-treatment, they aid stabilization during tissue adaptation and are suitable for growing patients.

• Hawley Retainer: Acrylic base with a stainless-steel labial bow; adjustable, durable, and customizable.

• Wraparound Retainer: Full-arch wire for independent tooth movement; aesthetic and usable as a temporary bridge or night guard.

• Essix/Vacuum-Formed Retainer: Clear thermoplastic, comfortable, aesthetic, same-day delivery; can correct minor tooth movements.

• Crozat Appliance: Flexible, hygienic design but fragile.

• Osamu Active Retainer: Clear, elastic, and adjustable for minor relapse.

• Vander Linden Retainer: Designed for lower anterior control with minimal occlusal interference.

• Astics Translucent Labial Bow: Fiber-reinforced aesthetic alternative to Hawley with good strength and color stability.

• Reinforced Removable Retainer: Hawley-type retainer strengthened with embedded metallic mesh; durable but may feel bulky.

• Positioner: Silicone appliance for final finishing, minor corrections, and occlusal refinement; effective but bulky and less aesthetic.

2. Fixed Retainers

Bonded wires placed on the lingual surfaces, commonly in the lower anterior region, ideal for long-term or permanent retention, particularly when relapse risk is high.

• Resin Fiberglass Bonded Retainer: Uses tooth-colored glass fibers; rigid, aesthetic, comfortable, and effective for patients with rotational corrections.

Conclusion

Retention is a vital phase in orthodontic treatment, maintaining alignment and occlusal harmony achieved during active therapy. Its success depends on appropriate selection of retainer type, material, and duration based on individual needs. Fixed retainers offer continuous stabilization, while removable ones allow better hygiene and flexibility. Advances in biomaterials and digital technology such as PEEK, shape memory alloys, nanocomposites, CAD/CAM, and 3D printing have improved strength, precision, and comfort. Despite these innovations, long-term success relies on good oral hygiene, follow-up, and patient compliance. Emerging smart and bioresponsive materials may enable adaptive retainers that respond to oral changes, guiding future research toward enhanced durability and patient-centered outcomes8,16.

References

[1] Bearn DR. Bonded orthodontic retainers: A Review. Am J Orthod Dentofacial Orthop 1995;108:207-213. [2] Ali A. Bahreman, Retention Considerations in the Assessment of Long-Term Stability in Early Versus Late Orthodontic Treatment. Sem Orth, 2016ae [3] Andriekute A, Vasiliauskas A, Sidlauskas A. A survey Of protocols and trends in orthodontic retention. Prog orthod 2017; 18:1-8 [4] Nucera R, Lo Giudice A, Matarese G et al. (2019) Orthodontic Materials: Scientific and Clinical Aspects. Switzerland:Springer. [5] Eliades T, Eliades G (2009) Dental Materials in Orthodontics: Biomaterials and Clinical Applications. London: Thieme. [6] Lagravère MO, Carey J, Toogood, RW et al (2017) Evidence-Based Orthodontics: A Biomechanical and Clinical Guide. Ber-Lin: Springer. [7] Rami Reddy MS, Suma S, Chandrase Khar BR, Ankur Chaukse. Retention Appliances-A Review. International Journal of Dental Clinics. 2010; 2(3):31-36. [8] Malandkar, A., Toshniwal, N. G., Mote, N., Das, S., & Singh, N. (2019). An overview of current trends in retention. International Journal of Applied Dental Sciences, 5(3), 240–245. [9] Vaida, L.L.; Bud, E.S.; Halitchi, L.G.; Cavalu, S.; Todor, B.I.; Negrutiu, B.M.; Moca, A.E.; Bodog, F.D. The Behavior of Two Types of Upper Removable Retainers-Our Clinical Experience. Children 2020, 7, 295. [10] Lorenzoni, D.C.; Henriques, J.F.C.; Silva, L.K.D.; Alves, A.C.M.; Berretin-Felix, G.; Janson, G. Users’ perceptions and pref-Erences towards maxillary removable orthodontic retainers: A crossover randomized clinical trial. Braz. Oral Res. 2019,33, e078. [11] Ponitz, R.J. Invisible retainers. Am. J. Orthod. 1971, 59, 266–272 [12] ASTICS Translucent Labial Bow|Orthodontic Products. Available online:orthodonticproductsonline.com (accessed on 8 January 2023). [13] Al-Suliaman, S.; Hashim, H.A.; Cordovez, J.L. The reinforced removable retainer. J. Contemp. Dent. Pract. 2006, 7, 145–152. [PubMed] [14] Park, Y.; Hartsfield, J.K.; Katona, T.R.; Eugene Roberts, W. Tooth positioner effects on occlusal contacts and treatment outcomes. Angle Orthod. 2008, 78, 1050–1056. [CrossRef] [PubMed] [15] Pravindevaprasad, A.; Therese, B.A. Tooth positioners and their effects on treatment outcome. J. Nat. SciBiol. Med. 2013, 4,298–301. [CrossRef] [PubMed] [16] Bhojwani, P. R., Gilani, R., Paryani, M., Vishnani, R., Bajaj, P., & Mankar, N. (2022). Orthodontic retainers – A review. Journal of Research in Medical and Dental Science, 10(12), 180–183. https://www.jrmds.in [17] White LW. The combination retainer. Orthod Pract 2011;2(2):72–73. [18] Taner T, Haydar B, et al. Short-term effects of fiberotomy on relapse Of anterior crowding. Am J Orthod Dentofacial Orthop 2000;118:617–623. DOI: 10.1067/mod.2000.110637. [19] McDermott P, Field D, et al. Operator and Patient Experiences with Fixed or Vacuum Formed Retainers. Cork: International Association Of Dental Research, 2007; 17 abstract. [20] Sun J, Yu YC, et al. Survival time comparison between Hawley And Clear Overlay Retainers: a Randomized Trial. J Dent Res 2011;90(10):1197–1201. DOI: 10.1177/0022034511415274 [21] Booth FA, Edelman JM, Proffit WR. Twenty-year follow-up of patients With permanently bonded mandibular canine-to-canine retainers. Am J Orthod Dentofac Orthop 2008; 133: 70-6. [CrossRef] [22] Al-Nimri K, Al Habashneh R, Obeidat M. Gingival health and relapse Tendency: a prospective study of two types of lower fixed retainers. Aust Orthod J 2009; 25: 142. [23] Stormann I, Ehmer U. A prospective randomized study of different Retainer types. J Orofac Orthop 2002;63:42–50. DOI: 10.1007/s00056-002-0040-6. [24] Booth F, Edelman J, et al. Twenty year follow-up of patients with Permanently bonded mandibular canine-to-canine retainers. Am J Orthod Dentofacial Orthop 2008;133:70–76. DOI: 10.1016/j.ajodo.2006.10.023. [25] Årtun J. Caries and periodontal reactions associated with long-term Use of different types of bonded lingual retainers. Am J Orthod 1984;86:112–118. DOI: 10.1016/0002-9416(84)90302-6. [26] Gould TE, Westover J, Hartsock L, Patel J (2016) Biocompatibility of polyetheretherketone vs. stainless steel orthodontic de-Vices: an in-vivo study. Angle Orthodontist, 86: 952-6. [27] Jamal A, Ponnusamy S, Alkheraif AA, et al. (2018) A pilot study into the cytotoxicity and surface roughness of two ortho-Dontic retention wires. Progress in Orthodontics, 19: Jour [28] Parker A, Harris A (2019) Aesthetic orthodontics: Current concepts and treatment planning. British Dental Journal, 226:143-50. [29] Vande Vannet, B. (2024). Advancements in emerging orthodontic materials: A comprehensive review for practitioners and researchers. Stechnolock Archives of Materials Science, 3(1), 1–8. https://www.stechnolock.com [30] Martins RP, Buschang PH, Gandini LG (1999) Dentoalveolar changes with a Begg-type technique and with the preadjusted Edgewise appliance. American Journal of Orthodontics and Dentofacial Orthopedics, 116: 177-186. [31] Li Y, Tian L, Guo X, Wang X (2018) Shape memory polymer-based smart dental braces: concept, materials, and fabrication. International Journal of Polymeric Materials and Polymeric Biomaterials, 67: 536-43.

Copyright

Copyright © 2025 Dr. Simi Vinod , Dr. Sharmila Kumari V , Dr. Vishalini E , Dr. Jeevana Poovalingam , Dr. Keerthana S, Dr. Nivedhita AT , Dr. Karthikeyan MK , Dr. Raj Vikram N. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.