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Clear aligner generations and orthodontic tooth movement

Updated: Feb 28, 2023

Orthodontic tooth movement is a complex process that needs the cooperation of various biological reactions, including cell signaling and bone remodeling. This involves the removal of mineralized bone by osteoclasts and the creation of a new bone structure by osteoblasts, which eventually becomes mineralized.

For smooth orthodontic tooth movement to occur, clear aligners are expected to fulfill elaborate criteria and given the massive developments of aligner technology, this is much better executed today than it would be a few decades earlier!

The past 15 years have witnessed the most progress in clear aligner technology in terms of its versatility to correct an array of dental anomalies as well as to accomplish a wider range of tooth movements.

That being said, the potential of clear aligners in delivering precise and effective results is promising! This article describes the different generations of clear aligners that have been available from the onset and how their uses have been highlighted in orthodontics.

This study was conducted by authors Hennessy, J and Al-Awadhi EA from Dublin, Ireland. It was published in the Journal of Orthodontics.

Clear aligners generations and orthodontic tooth movement.

Hennessy J(1), Al-Awadhi EA(2).

J Orthod. 2016 Mar;43(1):68-76. doi: 10.1179/1465313315Y.0000000004.

Author information:

  1. Dublin Dental University Hospital, Specialist Registrar in Orthodontics, Child Dental Health and Orthodontics, Lincoln Place, Dublin, Ireland.

  2. Dublin Dental University Hospital, Consultant, Child Dental Health and Orthodontics, Lincoln Place, Dublin, Ireland.

Clear aligner generations

In 1999, Align technology was the first to launch a clear aligner system using CAD/CAM technology, popularly known today as Invisalign. While it was first adopted to benefit orthodontics, today, it has expanded to general practitioners as well. The Invisalign system consists of a series of thermoplastic clear aligners that are switched every 1 to 2 weeks until the desired positioning of the teeth is achieved. Each aligner is staged to achieve anywhere from 0.25 to 0.30 mm of orthodontic tooth movement per tray.

Each generation of clear aligners has adapted new enhancements to achieve varied results.

  • First generation: The first generation of clear aligners worked based on a displacement-driven system, meaning that they relied solely on the shape of the aligners to achieve results. No auxiliary elements were incorporated, and limited research was available to support the efficacy of these aligners.

  • Second generation: In this generation, the use of auxiliary elements began gaining momentum. These auxiliaries were used to enhance the efficacy of orthodontic tooth movement and included the use of attachments, the incorporation of composite buttons, and intermaxillary elastics.

  • Third generation: By far the latest generation of clear aligners, the third generation further enhanced the concept of using auxiliaries and introduced optimized attachments that can be placed automatically by the manufacturer’s software. These aligners are intended to improve control of tooth movements by adapting their shape with consideration to the individual tooth morphology. These are typically placed when complex tooth movements like derotations, extrusions and root movements are required. The most commonly used types of attachments are ellipsoid, beveled, and rectangular attachments.

Various studies have been done on the three generations of aligners. See the table below:

The study was finally able to conclude that clear aligners can achieve reliable and effective results with mild and medium cases of malocclusion. More clinical research will promote advances in aligner technology, as well as the overall growth of the clear aligner market.

OEM clear aligner manufacturers such as K Line Europe are working hard to increase precision, reliability and comfort in orthodontic tooth movement through clear aligners.

Would you like to know more about the workings of our clear aligners?

Check out our blog post on the unique materials and techniques we use to ensure the best results possible!


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