The first forerunner of the aligner was H.D. Kesling’s “tooth positioner” that first appeared in 1945. This was an appliance made from rubber that looked similar to a sports mouth guard and enclosed both teeth quadrants. This was used at the end of the treatment in conjunction with a fixed brace to significantly shorten the time that it took to make the final corrections to the position of the teeth. Positioners are still available today but they have long since been made from flexible silicon. Many orthodontists came upon the idea of using two-piece positioners for just one teeth quadrant. These look very similar to today’s aligners.
From 1960 onwards, writers such as Nahoum and Ponitz started to describe one-piece plastic splints. These were mainly used to stabilise the results of treatment but were also used for minor corrections to the position of the teeth. At the end of the eighties, a Japanese man, Yoshii appeared with his Elasto devices made from highly flexible silicon that could be used for either one or two teeth quadrants. These have been sold in Germany since 1991 by the Hinz Kfo Laboratory. Tooth movements in the order of 3 mm were possible using a single Elasto appliance because of the great resilience of highly flexible silicon. In the 1990’s the American J. Sheridan developed his own Aligner System whereby the plastic splints could be repeatedly activated by gradually inserting slots and little pins. Sheridan’s ESSIX Aligner did gain a certain currency but, as before, its use was mainly confined to minor corrections of the front teeth.
At around the same time, towards the end of the 1990’s, two new aligner systems were developed that made it possible to achieve greater movement of the teeth: they were the Invisalign from the USA (1997) and the Clear Aligner System developed by T-W. Kim of Korea in 1998. The Invisalign treatment was introduced in 1999 at the American Orthodontics Conference. The innovative thing about Align was that a whole series of computer-aided models, right up to the desired end result, could be produced from one single impression of the teeth. These models could then be used to produce a randomly large series of aligners for a patient without having to take any new impressions. Fascinating though this may be, it was unfortunate that Align was then able to get a US patent to produce more than three aligners from a single impression. But any orthodontic technician had already been able to do this for some time without the aid of computer technology. So, what we have here is a trivial patent that, in the eyes of many specialists, has been wrongly granted. This patent enabled Align to sue any potential competitors right out of the market. The best known victim of this strategy was the American company OrthoClear in 2006. Not even in Germany are competitors of Align protected from such legal action. Align’s American patents prevent other companies from developing their products organically because this will always put them in danger of infringing the patent. In spite of this, there are presently companies in many European countries that compete with Align and its Invisalign product.
Invisalign was introduced onto the German market in 2001. In the same year, possibly as a result of inept public relations work on the part of the Align company, a statement was published by the German Association of Orthodontists (DGKFO) that rated Aligner treatment very negatively, thereby damaging the image of aligner therapy in general. In 2004, the DGKFO issued a revised statement which acknowledged the potential of Aligner treatment. In 2007, some orthodontists who were particularly interested in aligners set up the German Association of Aligner Orthodontists (DGAO). The association’s first conference was organised in 2010. Whether it makes sense to set up an association for every single treatment option remains to be seen – but if it pleases them…