The history of the Lingual Technique
The lingual technique was developed from 1970 onwards out of the need to offer an “invisible” orthodontic treatment for an aesthetically demanding clientele. In the beginning, common brackets were bonded directly onto the lingual surfaces (=inner surfaces) of the teeth. It was mainly Craven Kurz in the USA and K. Fujita in Japan who treated the first patients with lingually attached brackets.
The first cases were treated with standard labial brackets, which were simply bonded lingually. The use of conventional brackets for the lingual technique soon proved to be problematic, so that the need for a special lingual bracket system arose. Kurz patented his own lingual bracket in 1976, Fujita in 1978.
First Boom and Disappointment
However, the first boom in lingual technique in the USA soon died out again, because often only modest results could be achieved with the less specific materials and procedures of the early years – “invisible appliance, invisible results”, as scoffers put it. However, this has changed so thoroughly up to now that treatment tasks of all degrees of difficulty can now be solved with the lingual technique without any loss of quality.
Some of the first orthodontists to work with lingual technology, including C. Kurz, joined forces in the 1970s in the ORMCO Lingual Technology Task Force, a group supported by a large orthodontic product manufacturing company.
From Ormco’s 7th Generation to Fully Customised Brackets: Incognito and WIN
The Ormco Task Force Lingual Technique developed a lingual bracket from the mid-1970s onwards, which was continuously improved. The bracket continued to be developed until the 7th generation, which has not been changed for over 20 years thereafter.
After 2010, ORMCO discontinued the 7th generation bracket and relied only on the STb bracket, which was originally developed by Takemoto and Scuzzo and purchased by ORMCO around 2010. Various dental laboratories have started to develop increasingly sophisticated laboratory processes for indirect bonding of lingual brackets in the mouth. Furthermore, numerous other companies have launched their own ready-made lingual brackets, of which probably only Ormco’s STb bracket has a wider distribution.
Since 2020, ORMCO has even offered a self-ligating lingual bracket, the ALIAS bracket, for which no reports are yet available. The Fujita bracket is widespread in Japan, but is only offered there.
Because tooth shapes are very variable, especially on the inner side, and also because there was a need to design a particularly flat, low-impact bracket, the idea of making a fully customised lingual bracket came up. The first bracket of this kind was the Incognito bracket developed by Dirk Wiechmann, which was on the market from 1996 and has been distributed by 3M-Unitek since 2010. Together with the pre-positioned brackets, fully individualised brackets always come with a set of precisely pre-bent wires. The combination of individualised brackets with these wires simplifies the lingual treatment considerably and enables short treatment times and particularly good results.
Wiechmann launched the WIN bracket in 2013, which looks very similar to the Incognito bracket. However, Incognito is made from an alloy containing gold using a casting process, while WIN is produced from a steel alloy using a laser sintering process. In the meantime, an individualised lingual bracket from China is also available, but no literature can be found about it.
The fully individualised brackets have the advantage of applying very little pressure and thus improving patient comfort, and thanks to their manufacturing process they have a much greater precision than any lingual bracket produced before. This precision is particularly important in the lingual technique because poor dimensional accuracy of the bracket slots as well as errors in bracket positioning have a greater impact here than in the usual technique with brackets on the outside.