It has to do with braces that are bonded on the lingual surface of the teeth and are totally invisible as a result. The lingual braces that are used in our practice (www. Incognito.net) are computer made in the 3M laboratory in Germany, after that the orthodontist takes high precision impressions in the first diagnostic session. These braces are made of gold and are totally personalized, meaning that they are made in such a way as to fit the morphology of the lingual surface of only one particular patient. Their only disadvantage is their much higher cost when compared with all the other bracket types that are used in our practice.